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Scent-marking and territorial behaviour of Ethiopian wolves Canis simensis
Abstract
Scent-marking behaviour and inter-pack aggression were studied in wild Ethiopian wolf, Canis simensis, packs. Raised-leg urinations, followed by ground scratching, were the most frequently deposited scent-mark. Scent-marking rates were highest along or near territory boundaries, where distances between scent-marking sites were reduced and the proportion of multiple marks was increased, relative to other areas. Marking rates increased with wolf numbers during patrols but not during other activities. Although all adult members of a pack contributed to scent-marking, the dominant pair marked most frequently. Subadult males scent-marked occasionally but subadult females never did. Wolves vigorously over-marked neighbours' scent-marks. Most direct encounters between neighbouring wolves at territory borders were aggressive and involved repeated chases, and the larger group was most likely to win. Resident wolves were more tolerant of opposite-sex than same-sex neighbours. Resident wolves therefore signalled pack composition and status at home range borders by olfactory and auditory cues and by aggressive contests. Such signalling may reduce the occurrence of potentially costly inter-pack aggressive encounters at territory borders and provide information on reproductive status.
... Nilgai are abundant in South Texas, with estimates of over 36,700 animals (Traweek and Welch 1992). Nilgai can breed year-round, but the peak in nilgai breeding occurs between December-March (Fall 1972;Sheffield et al. 1983). Nilgai provide a significant economic benefit as a huntable resource in Texas but may compete for forage with native herbivores and livestock (Sheffield 1983;Kahn 2014), serve as a host for cattle fever ticks (Teel et al. 1996), and damage fences (Sheffield et al. 1983;Zoromski 2019). ...
... This suggests that the physical location of latrines is important. The most comprehensive review of nilgai biology implied regular use of latrines by both sexes and all age-classes (Leslie 2008) with reference to Blanford (1888), Brander (1923), Dharmakumar-sinhji (1959), Schaller (1967), Fall (1972), Prater (1980, Sheffield et al. (1983). Most of these studies are based on summaries of casual observations, with the exception of Sheffield et al. (1983) which documented latrine abundance but not usage by age-sex class, and Fall (1972) who monitored fresh defecations on latrines but noted observations of individual defecations observed in the field. ...
... The most comprehensive review of nilgai biology implied regular use of latrines by both sexes and all age-classes (Leslie 2008) with reference to Blanford (1888), Brander (1923), Dharmakumar-sinhji (1959), Schaller (1967), Fall (1972), Prater (1980, Sheffield et al. (1983). Most of these studies are based on summaries of casual observations, with the exception of Sheffield et al. (1983) which documented latrine abundance but not usage by age-sex class, and Fall (1972) who monitored fresh defecations on latrines but noted observations of individual defecations observed in the field. While we documented all age and sex classes defecated on latrines, our results revealed that latrine usage differed by nilgai sex and age-classes. ...
The use of scent for communication is widespread in mammals, yet the role of scent-marking in the social system of many species is poorly understood. Nilgai antelope (Boselaphus tragocamelus) are native to India, Nepal, and Pakistan. They were introduced to Texas rangelands in the United States during the 1920s to 1940s, and have since expanded into much of coastal South Texas and northern Mexico. The nilgai social system includes the use of latrines or repeated defecation at a localized site. We quantified and described physical and behavioral characteristics of nilgai latrine ecology to investigate drivers of latrine use at three sites in South Texas, during April 2018 to March 2019. Latrines were abundant (2.6–8.7 latrines/ha on unpaved roads, 0.4–0.9 latrines/ha off-roads), with no evidence for selection as to vegetation communities; latrines were dynamic in persistence and visitation rates. We found higher densities of latrines in Spring surveys, just after the peak of nilgai breeding activity, compared to Autumn surveys. Density of nilgai latrines was 3–10 times greater than estimated population densities, indicating individual nilgai must use multiple latrines. Camera traps and fecal DNA analysis revealed latrines were mainly (70%) visited by bulls and defecated on by bulls (92% in photos, 89% for DNA samples). The greatest frequency of visits occurred during the peak in the nilgai breeding season, from December–February; latrines were visited every 2–3 days on average. Body characteristics of photographed individuals and genetic analysis of feces indicated repeated visits from the same individuals. Nilgai cows occasionally used latrines; their use was sometimes followed by bulls showing flehmen responses after a female defecated or urinated on the latrine. We propose that dominant bulls use latrines for territory demarcation to display social dominance to both cows in estrus and subordinate bulls. Cows likely use latrines to communicate reproductive status. This study is the first intensive assessment focused on latrine ecology in nilgai. Our results directly contradict anecdotal descriptions of latrine use and behavior in nilgai but are consistent with predictions of antelope social systems based on body size, feeding type, and group dynamics.
... Primary costs are likely competition (Brown 1964, Hixon 1980, Carpenter 1987) and travel (Mitchell & Powell 2004, because competition is inherent to territoriality and energy is needed to access and defend resources. Territory holders with lower competitive ability may also pay higher costs to compete against more-competitive conspecifics (Packer et al. 1990, Sillero-Zubiri and Macdonald 1998, Cassidy et al. 2015, Sells and Mitchell 2020. Mortality risk may also be a primary cost where predator density is high if it affects how animals select and use their territory (Sargeant et al. 1987, Whittington et al. 2005, Rich et al. 2012). ...
... Packs generally comprise a dominant breeding pair and their offspring from multiple years who cooperatively defend the territory, hunt, and raise pups. Larger groups of carnivores may have greater competitive ability (Packer et al. 1990, Sillero-Zubiri and Macdonald 1998, Cassidy et al. 2015 and therefore reduced costs of competition with neighboring groups. Wolves are coursing predators who travel long distances, and such movement is energetically costly. ...
... Territory holders with lower competitive ability may pay higher costs to compete against morecompetitive conspecifics (Sells and Mitchell 2020). Among social carnivores, competitive ability appears linked to group size (Packer et al. 1990, Sillero-Zubiri and Macdonald 1998, Cassidy et al. 2015. As predicted if cost of competition varies inversely with pack size (Figs. ...
Improving estimation of wolf recruitment and abundance, and development of an adaptive harvest management program for wolves in Montana. Final Report for Federal Aid in Wildlife Restoration Grant W-161-R-1.
... Groups generally consist of a dominant breeding pair and their offspring from multiple years who cooperatively defend the territory, hunt and raise pups. Larger groups of carnivores may have the greater competitive ability [18][19][20] and therefore reduced costs of competition with neighbouring groups. Wolves are coursing predators who traverse long distances, and such movement is energetically costly. ...
... Primary costs are probably competition [12,16,17] and travel [8][9][10] because the competition is inherent to territoriality and energy is needed to access and defend resources. Territory holders with lower competitive ability may pay higher costs to compete against more-competitive conspecifics [18][19][20]. Mortality risk may also be a primary cost if it affects how animals select and use their territory [21,22]. From Sells & Mitchell [11]. ...
... Territory holders with lower competitive ability may pay higher costs to compete against more-competitive conspecifics [11]. Among social carnivores, competitive ability appears linked to group size [18][19][20]. As predicted if cost of competition varies inversely with group size (figures 4 and 5; table 1), territories were smaller for groups of greater size in this high-density population (estimated at 16 individuals per 1000 km 2 in occupied range [66]). ...
As an outcome of natural selection, animals are probably adapted to select territories economically by maximizing benefits and minimizing costs of territory ownership. Theory and empirical precedent indicate that a primary benefit of many territories is exclusive access to food resources, and primary costs of defending and using space are associated with competition, travel and mortality risk. A recently developed mechanistic model for economical territory selection provided numerous empirically testable predictions. We tested these predictions using location data from grey wolves (Canis lupus) in Montana, USA. As predicted, territories were smaller in areas with greater densities of prey, competitors and low-use roads, and for groups of greater size. Territory size increased before decreasing curvilinearly with greater terrain ruggedness and harvest mortalities. Our study provides evidence for the economical selection of territories as a causal mechanism underlying ecological patterns observed in a cooperative carnivore. Results demonstrate how a wide range of environmental and social conditions will influence economical behaviour and resulting space use. We expect similar responses would be observed in numerous territorial species. A mechanistic approach enables understanding how and why animals select particular territories. This knowledge can be used to enhance conservation efforts and more successfully predict effects of conservation actions.
... This may indicate that some packs may be visiting SMSs only to receive information and may be more reluctant to transmit information if a neighbouring pack has previously marked. Alternatively, marking itself may stimulate remarking at an SMS, which may operate as positive feedback to help ensure adequate territorial marking, a behaviour seen in both grey wolves (Peters & Mech, 1975) and Ethiopian wolves (Sillero-Zubiri & Macdonald, 1998), although these conclusions should be considered with caution as the trend was nonsignificant. Contrary to what one should expect if the function of SMS was purely territorial, during visits to SMSs both resident packs and dispersing coalitions investigated locations through sniffing, and they both deposited scent through marking. ...
... SMSs are unlikely to be used for navigation by dispersers; marking sites are found throughout African wild dog ranges and we have no evidence that dispersing individuals respect territory boundaries as other species do, such as Ethiopian wolves and red foxes, where floaters tend to inhabit gaps between territorial boundaries (Dekker et al., 2001;Sillero-Zubiri & Gottelli, 1995). Multifunctionality of latrines is not uncommon (Buesching & Jordan, in press), and is seen in European badgers (Stewart et al., 2002), honey badgers, Mellivora capensis (Begg et al., 2003), Ethiopian wolves (Sillero-Zubiri & Macdonald, 1998) and meerkats (Jordan et al., 2007). ...
Scent marks deposited as semiochemical signals are a primary mode of communication for a broad range of mammal species. Such scent signals are often deposited at specific, frequently visited marking sites called latrines. Despite descriptions of widespread latrine use by numerous mammal species, detailed understanding of site visit rates and latrine function is lacking. Here we report for the first time a quantitative assessment of scent-marking behaviours that represent interpack olfactory communication by African wild dogs, Lycaon pictus, at latrines visited by multiple resident neighbouring packs, hereafter called a ‘shared marking site’ (SMS). We show that multiple packs visited specific SMSs frequently and regularly throughout the year, with a notable decrease in visits during the 3-month denning season coinciding with a contraction in range size. In addition to resident neighbouring packs, dispersing individuals visited and scent-marked at SMSs, suggesting that latrines function at least in part as sites communicating information about residence and possibly reproductive status. Further detailed investigation of the relevance of latrine use to territorial behaviour, ranging, habitat use and dispersal in this species is required, particularly as it may have direct applied conservation implications for this wide-ranging but territorial endangered species.
... Chapter 4 demonstrates that groups of buffalo tend to avoid each other spatially and temporally, but the underlying mechanisms are unknown. Many social species defend their territories to have exclusive access to resources and different patterns of territory marking are adopted (Miura 1984, Grant et al. 1992, Sillero-Zubiri and Macdonald 1998, Lazaro-Perea 2001. Animals can defend their territories through fighting (Sillero-Zubiri and Macdonald 1998), but the quasi-absence of direct contacts observed in my study suggests that buffalo groups do not actively defend their home ranges. ...
... Animals can defend their territories through fighting (Sillero-Zubiri and Macdonald 1998), but the quasi-absence of direct contacts observed in my study suggests that buffalo groups do not actively defend their home ranges. Buffalo may thus adopt indirect strategies to inform ownership to intruders and therefore avoid conspecifics, such as scent-marking or vocalizations already observed in many species (Waser 1975, Sillero-Zubiri andMacdonald 1998). Buffalos use different types of vocalization for maintaining group cohesion (Mloszewski 1983), it is, therefore, possible that neighbouring groups interact with each other through vocalizations to inform on their location. ...
My thesis focused on understanding the social ecology of African buffalo in several southern African populations to better understand the risk of pathogen transmission within this species. Using GPS and genetic data from buffalo, the objectives of my thesis were to (1) quantify the dynamics of interactions within and between groups of buffalo and examine the influence of seasonality and inter-population variance on these dynamics; (2) investigate whether dispersal was sex-biased at different two organizational levels, i.e. between groups and between populations, to assess the influence of animal sex in pathogen spread between populations; and (3) examine the impact of intragroup dynamics on the spread of a directly transmitted pathogen as a model to link host social organization and pathogen transmission.
... When the origins of non-residents were examined, over half were known or probable neighbours, consistent with reports in Ethiopian wolves (Sillero-Zubiri & Macdonald 1998). However, this is almost certainly an underestimate: having not studied all adjacent territories I was not familiar with every neighbour, so it is possible that some strangers were actually neighbours. ...
... Although the role of subordinate foxes in territorial defence is uncertain(Arnold et al. 2011), there is mixed evidence that subordinates contribute to defence in other canids. Subordinate coyotes and Ethiopian wolves contribute to territorial defence by scent marking and physical eviction, though to a lesser extent than dominants(Gese & Ruff 1997;Sillero- Zubiri & Macdonald 1998;Gese 2001) and in coyotes increased pack size does not reduce the scent marking rate of any other pack member ...
The red fox (Vulpes vulpes) is a contentious species of global importance as a predator, competitor, vector of disease and pest. Understanding their social system is essential for successful species management and mitigating human-wildlife conflict. Foxes are solitary foragers that form groups in certain circumstances. It is unclear whether these groups are beneficial or simply the ‘best of a bad job’ due to ecological constraints. Further, little is known about how stable or cohesive fox groups are, which can have implications for disturbance or removal. I addressed these issues to further our understanding of how fox groups operate.
I set up camera traps in residential gardens where foxes were fed (food patches), to study social and competitive relationships in the high density fox population of suburban Bristol, UK. I collected over 152,000 photos of foxes and identified 192 individuals.
Social groups were difficult to define, but the most reliable definition encompassed shared space use, a sighting threshold and the number of social connections. Group membership was relatively stable; foxes associated in communities, mainly within their territory boundary and maintained long term relationships that lasted until death or emigration. However, in all seasons the majority of relationships lasted less than a day and were probably between foxes from different social groups, indicating that intergroup contacts were not uncommon and occurred year round.
Food patches were hotspots for sociality. Foxes improved their foraging efficiency by selecting high quality patches and coinciding their foraging activity with anticipated food availability, which increased contact rates at high quality patches. Females foraged according to their seasonal energetic demands, while males reduced their foraging effort in the winter mating season in favour of mate-searching behaviour. This contributed to a significant alteration in social structure in winter, with an increased rate of territory intrusion by strangers, a greater proportion of short term relationships and reduced social connectivity, demonstrating a role of females in maintaining group cohesion in winter.
Dominant foxes occupied central network positions and therefore had a major influence on group connectedness; the demise of a dominant male led to significant social perturbation in one territory, supporting the importance of breeders in canid groups. Dominance also facilitated priority access to food, but so too did resident group membership, perhaps through familiarity with local resources and conspecifics. Subordinates compensated for intragroup competition by utilising lower quality patches and risky extraterritorial foraging, which was observed at an unexpectedly high rate year round. Contrary to the resource dispersion hypothesis, this indicated that group size was not limited by within-territory resources.
To my knowledge, this is the most detailed study of fox sociality to date. Despite low contact rates fox groups were relatively stable and more similar in complexity to other canids than previously acknowledged. High individual flexibility in space use and year-round extraterritorial movement may have functioned to mitigate competition, but also explained how foxes responded so rapidly to local demographic change, providing evidence for the futility of management by removal.
... Many territories are held by a solitary individual or breeding pair. Group territoriality is relatively uncommon but likely influences a territory's economic defendability; e.g., larger packs of Ethiopian wolves (Canis simensis; Sillero-Zubiri and Macdonald, 1998) and prides of lions (Packer et al., 1990) appear more competitive in confrontations with smaller groups. ...
... Mattisson et al. (2013) also reported an uncertain effect of competition on territory sizes in gray wolves, but similarly did not control for territory size. 4 Larger groups appear to have greater competitive ability (Cassidy et al., 2015;Packer et al., 1990;Sillero-Zubiri and Macdonald, 1998). 5 Food resources in these scenarios likely were relatively evenly distributed, as striped parrotfish fed on algae that grew abundantly throughout their territories (Clifton, 1989), and coyotes relied heavily on snowshoe hares (Lepus americanus, Patterson and Messier, 2001). ...
Territorial behavior is a fundamental and conspicuous behavior within numerous species, but the mechanisms driving territory selection remain uncertain. Theory and empirical precedent indicate that many animals select territories economically to satisfy resource requirements for survival and reproduction, based on benefits of food resources and costs of competition and travel. Costs of competition may vary by competitive ability, and costs of predation risk may also drive territory selection. Habitat structure, resource requirements, conspecific density, and predator distribution and abundance are likely to further influence territorial behavior. We developed a mechanistic, spatially-explicit, individual-based model to better understand how animals select particular territories. The model was based on optimal selection of individual patches for inclusion in a territory according to their net value, i.e., benefits (food resources) minus costs (travel, competition, predation risk). Simulations produced predictions for what may be observed empirically if such optimization drives placement and characteristics of territories. Simulations consisted of sequential, iterative selection of territories by simulated animals that interacted to defend and maintain territories. Results explain why certain patterns in space use are commonly observed, and when and why these patterns may differ from the norm. For example, more clumped or abundant food resources are predicted to result, on average, in smaller territories with more overlap. Strongly different resource requirements for individuals or groups in a population will directly affect space use and are predicted to cause different responses under identical conditions. Territories are predicted to decrease in size with increasing population density, which can enable a population's density of territories to change at faster rates than their spatial distribution. Due to competition, less competitive territory-holders are generally predicted to have larger territories in order to accumulate sufficient resources, which could produce an ideal despotic distribution of territories. Interestingly, territory size is predicted to often show a curvilinear response to increases in predator densities, and territories are predicted to be larger where predators are more clumped in distribution. Predictions consistent with empirical observations provide support for optimal patch selection as a mechanism for the economical territories of animals commonly observed in nature.
... The posture used during scent marking and also the frequency that an animal scent marks are commonly related with its sex and dominance rank (Leuchtenberger and Mourao 2009;Müller and Manser 2008;Sillero-Zubiri and Macdonald 1998). Dominant males tend to mark more often, and it is also common that the dominant overmark the scent of other members of its group (Leuchtenberger and Mourao 2009;Sillero-Zubiri and Macdonald 1998). ...
... The posture used during scent marking and also the frequency that an animal scent marks are commonly related with its sex and dominance rank (Leuchtenberger and Mourao 2009;Müller and Manser 2008;Sillero-Zubiri and Macdonald 1998). Dominant males tend to mark more often, and it is also common that the dominant overmark the scent of other members of its group (Leuchtenberger and Mourao 2009;Sillero-Zubiri and Macdonald 1998). Overmarking may be a strategy of reproductive suppression, especially when the dominant individual has reproductive priority within the group (Palagi et al. 2004). ...
... To study the spatial distribution of scent marking, researchers have been limited to tracking field signs in snow [30][31][32][33] . This method may not provide information on animal identity that is important for social species, as their scent marking activity and strategy may differ according to factors such their place in the social hierarchy 34 . Tracking in the snow is also restrictive because it cannot be used in warm climates or at times of year in which snow is absent. ...
... Over-marking is an important social process, implicated in pair-bonding 100,101 , as an agonistic response to territorial encroachment 32 , or for amplification of within-group scent marks to convey additional information on pack size and composition to would-be-intruders (e.g. 34 ). The novel bio-logging approach proposed here provides a record of scent marking activity over a period long enough to assess revisitation and over-marking activities for the first time. ...
For canid species, scent marking plays a critical role in territoriality, social dynamics, and reproduction. However, due in part to human dependence on vision as our primary sensory modality, research on olfactory communication is hampered by a lack of tractable methods. In this study, we leverage a powerful biologging approach, using accelerometers in concert with GPS loggers to monitor and describe scent-marking events in time and space. We performed a validation experiment with domestic dogs, monitoring them by video concurrently with the novel biologging approach. We attached an accelerometer to the pelvis of 31 dogs (19 males and 12 females), detecting raised-leg and squat posture urinations by monitoring the change in device orientation. We then deployed this technique to describe the scent marking activity of 3 guardian dogs as they defend livestock from coyote depredation in California, providing an example use-case for the technique. During validation, the algorithm correctly classified 92% of accelerometer readings. High performance was partly due to the conspicuous signatures of archetypal raised-leg postures in the accelerometer data. Accuracy did not vary with the weight, age, and sex of the dogs, resulting in a method that is broadly applicable across canid species’ morphologies. We also used models trained on each individual to detect scent marking of others to emulate the use of captive surrogates for model training. We observed no relationship between the similarity in body weight between the dog pairs and the overall accuracy of predictions, although models performed best when trained and tested on the same individual. We discuss how existing methods in the field of movement ecology can be extended to use this exciting new data type. This paper represents an important first step in opening new avenues of research by leveraging the power of modern-technologies and machine-learning to this field.
... White markings associated with intraspecific communication may help explain the evolution of divergent coat patterns related to visual communication and circadian cycle combined. Unlike acoustic and chemical signals, which may reach a potential prey or a predator, even if its view is obstructed [18,19,20], visual signals decrease the possibility of prey/predator intercepting a message intended for closer conspecifics warning about their presence. In turn, acoustic and chemical communication play important roles in advertising territory occupation and ownership [18,20,21]. ...
... Unlike acoustic and chemical signals, which may reach a potential prey or a predator, even if its view is obstructed [18,19,20], visual signals decrease the possibility of prey/predator intercepting a message intended for closer conspecifics warning about their presence. In turn, acoustic and chemical communication play important roles in advertising territory occupation and ownership [18,20,21]. This highlights white marks, as well as acoustic and chemical communication, as functional traits that may increase the fitness of organisms and/or their influence on other organisms and on ecosystem functions [22]. ...
Melanism in the cat family has been associated with functions including camouflage, ther-moregulation and parasite resistance. Here we investigate a new hypothesis proposing that the evolution of melanism in cats has additionally been influenced by communication functions of body markings. To evaluate this hypothesis, we assembled a species-level data set of morphological (body marks: white marks on the backs of ears) and ecological (circadian activity: arrhythmic/nocturnal, and environmental preference: open/closed) characteristics that could be associated with communication via body markings, and combined these data with a dated molecular phylogeny. Next, we tested the association between melanism and communication, first by relating species' body marks with their ecological conditions, using a Bayesian implementation of the threshold model. Second, to explore the evolution of characteristics potentially influencing melanism in cat species, we modeled their evolution relative to melanism using models of coordinated vs. independent character changes. Our results suggest that white marks are associated with intraspecific communication between individuals that have non-melanistic phenotypes, as well as towards melanistic individuals (without white marks). The absence of white marks in a melanistic individual tends to be a limiting condition for intraspecific visual communication at night, resulting in an evolutionary dilemma for these species, i.e. to be almost invisible at night, but not to communicate visually. The comparative analysis of several evolutionary models indicated more support for the evolution of melanism being coordinated with the evolution of arrhythmic activity and white marks on the backs of ears.
... White markings associated with intraspecific communication may help explain the evolution of divergent coat patterns related to visual communication and circadian cycle combined. Unlike acoustic and chemical signals, which may reach a potential prey or a predator, even if its view is obstructed [18,19,20], visual signals decrease the possibility of prey/predator intercepting a message intended for closer conspecifics warning about their presence. In turn, acoustic and chemical communication play important roles in advertising territory occupation and ownership [18,20,21]. ...
... Unlike acoustic and chemical signals, which may reach a potential prey or a predator, even if its view is obstructed [18,19,20], visual signals decrease the possibility of prey/predator intercepting a message intended for closer conspecifics warning about their presence. In turn, acoustic and chemical communication play important roles in advertising territory occupation and ownership [18,20,21]. This highlights white marks, as well as acoustic and chemical communication, as functional traits that may increase the fitness of organisms and/or their influence on other organisms and on ecosystem functions [22]. ...
Melanism in the cat family has been associated with functions including camouflage, ther-moregulation and parasite resistance. Here we investigate a new hypothesis proposing that the evolution of melanism in cats has additionally been influenced by communication functions of body markings. To evaluate this hypothesis, we assembled a species-level data set of morphological (body marks: white marks on the backs of ears) and ecological (circadian activity: arrhythmic/nocturnal, and environmental preference: open/closed) characteristics that could be associated with communication via body markings, and combined these data with a dated molecular phylogeny. Next, we tested the association between melanism and communication, first by relating species' body marks with their ecological conditions, using a Bayesian implementation of the threshold model. Second, to explore the evolution of characteristics potentially influencing melanism in cat species, we modeled their evolution relative to melanism using models of coordinated vs. independent character changes. Our results suggest that white marks are associated with intraspecific communication between individuals that have non-melanistic phenotypes, as well as towards melanistic individuals (without white marks). The absence of white marks in a melanistic individual tends to be a limiting condition for intraspecific visual communication at night, resulting in an evolutionary dilemma for these species, i.e. to be almost invisible at night, but not to communicate visually. The comparative analysis of several evolutionary models indicated more support for the evolution of melanism being coordinated with the evolution of arrhythmic activity and white marks on the backs of ears.
... In extreme cases, they can lead to the death of one or more of the individuals involved (e.g., insects 7 and mammals 8 ). In general, such agonistic interactions serve to defend territories, food resources, or access to sexual partners (e.g., poisonous frogs, 9 birds, 10 and mammals [11][12][13][14]. ...
Lethal intergroup encounters occur in many species because of sexual selection. While documented in mountain gorillas, they are absent in western gorillas as, instead, it is predicted by their higher feeding (frugivory) and mate competition (single-vs. multi-male groups). We investigate whether the injuries on three dead silverbacks and one adult female from four groups of western gorillas in the Central African Republic, resulted from interactions with gorillas or leopards. We identified two distinct injury patterns caused by gorillas (isolated lacerations, round wounds) and leopards (punctures clustered on head/neck) by analyzing injuries caused by mountain gorillas and leopards to gorillas and non-gorilla species, respectively. The western gorilla injury pattern is similar to that of mountain gorillas suggesting that lethal encounters occur, albeit infrequently, as predicted by sexual selection in a one-male society. While sexual dimorphism and polygynous sociality favored the evolution of violent encounters, multiple males in groups may influence their frequency.
... For example, Ethiopian wolves and coyotes (C. latrans) have been shown to actively seek intruders following encounters with scents (Bowen and Cowan 1980;Sillero-Zubiri and Macdonald 1998). While our results did not show statistical significance about the slight delay in the revisitation of dingoes to sites, distinguishing these potential responses is an important avenue of future study and investigations would benefit from using larger sample sizes. ...
Chemical information in canid urine has been implicated in territoriality and influences the spacing of individuals. We identified the key volatile organic compound (VOC) components in dingo (Canis lupus dingo) urine and investigated the potential role of scents in territorial spacing. VOC analysis, using headspace gas chromatography–mass spectrometry (GC–MS), demonstrated that the information in fresh urine from adult male dingoes was sufficient to allow statistical classification into age categories. Discriminant function analyses demonstrated that the relative amounts or combinations of key VOCs from pre-prime (3–4 years), prime (5–9 years), and post-prime (≥10 years) males varied between these age categories, and that scents exposed to the environment for 4 (but not 33) days could still be classified to age categories. Further, a field experiment showed that dingoes spent less time in the vicinity of prime male dingo scents than other scents. Collectively, these results indicate that age-related scent differences may be discriminable by dingoes. Previous authors have suggested the potential to use scent as a management tool for wild canids by creating an artificial territorial boundary/barrier. Our results suggest that identifying the specific signals in prime-age male scents could facilitate the development of scent-based tools for non-lethal management.
... Subdominant females scent marking more than subdominant males (despite equal social status between the sexes) is consistent with observations in the intrapack context (Jordan et al., 2013), and aligns with mate defence theory, as has been described in other species (e.g. Ethiopian wolves, Sillero-Zubiri & Macdonald, 1998). ...
Keywords: canid carnivore communication latrine Lycaon scent marking social behaviour territoriality Individual patterns of scent marking can aid our understanding of the function of animal latrines. African wild dogs are pack-living social carnivores that regularly visit latrines, called shared marking sites, used by multiple neighbouring packs. Here we analysed scent marking by individual African wild dogs video captured at continuously monitored marking sites. Scent marking differed by sex and dominance status depending on social context (interpack versus intrapack exchanges). Dominants marked more frequently than subdominants, and patterns, particularly the order of overmarking, differed between the sexes. Dominant females were more likely than dominant males to overmark when the previous scent mark had been left by an individual from a different pack. Dominant males were more likely to leave the final, or top mark, regardless of social context or origin. Results are consistent with a resource defence advertisement function for wild dog latrines. However, sex-specific scent marking suggests the resource defended may differ between dominant females, which are more attentive to interpack scent marks, and dominant males, which are focused on overmarking a mate. The pattern of dominant male scent marking indicates that unambiguous advertisement of a bonded reproductive pair may be a critical component of communicating with neighbours about pack residence and territoriality.
... In extreme cases, they can lead to the death of one or more of the individuals involved (e.g., insects 7 and mammals 8 ). In general, such agonistic interactions serve to defend territories, food resources, or access to sexual partners (e.g., poisonous frogs, 9 birds, 10 and mammals [11][12][13][14]. ...
Abstract
Inter-group encounters leading to physical confrontation, and sometimes death, occur in many social animal species. The explanation put forward in polygynous species is sexual selection: strong competition between males for females, which exacerbates the violence of the encounters. In gorillas, the existence of lethal inter-group encounters has been recorded only in one very well studied subspecies, the mountain gorilla (Gorilla b. beringei) rising the question whether its absence in the other species, the western gorillas (G. gorilla), is linked to the strictly one-male society (as opposed to multi-male groups in mountain gorillas). Here, we aimed to investigate whether the cases of injured or dead western gorillas were the results of aggressive interactions with other gorillas or, alternatively, of the predation by leopards as mainly suggested by the literature. First, we analysed the injuries on four adults (three dead silverbacks and one injured adult female) recorded over 26 years of monitoring of four habituated groups in Central African Republic. We then identified two distinct injury patterns on victims of gorillas and leopards (based on wound body location, wound number in an area, wound types), by using available photos in the literature or the web of injuries issued during fights between mountain gorillas or leopard attacks to humans, monkeys, and duikers. Mountain gorillas mainly caused isolated lacerations and other gorilla-specific type of wounds over the whole body. Leopard caused mainly punctures, often clustered on the victim head, mainly the neck. A positive correlation existed between wound diversity and the number of wounds in the whole body or in a specific area in mountain gorilla victims but not in leopard victims, showing likely a more effective fighting technique of a predator. The injury pattern of western gorillas showed larger similarities with that of mountain gorillas, when compared to the leopard one. This is the first study suggesting that lethal encounters between adult western gorillas occur, even though rarely, in line with the theory of sexual selection in harem society species. Our findings shed light also on the species traits (e.g. large sexual dimorphism in body size, one- or multi-male polygynous sociality) and individual features (e.g. age of the leading male, group composition) that may have favoured the evolution of violent and lethal encounters in animal species.
... The first step in obtaining detailed information about the development of social interaction and communicative skills is the compilation of ethograms, or behavioral repertoires, based on direct observation (Bekoff et al. 1984). Although free ranging carnivore's ecology and behavior studies are successfully accomplished by following and observing them directly, direct observation 2003), and scent marking (Peters & Mech 1975;Bekoff 1978;Macdonald 1980;Sillero-Zubiri & Macdonald 1998). ...
The hoary fox, Lycalopex vetulus, is a small insectivorous canid endemic to grasslands of Central Brazil. Herein we characterize hoary fox social behavior, based on qualitative and quantitative differences in intraspecific communication among males, females, and subadults. A family group, two reproductive pairs and three other adult individuals of unidentified social status were directly observed from 1995 to 2001, for the continuous recording of all occurrences of behavioral events. Hoary fox exhibited behaviors related to communication and food consumption. A total of 4,240 behavioral events were recorded, most in the categories ‘Consumption’ (58%) and ‘Olfactory’ (23%). The frequencies of signaling types varied among individuals according to sex, age, and socioecological phase. Olfactory signalings were more frequent in adult males, and during the Mating and Dispersal phases. Acoustic signalings were more frequent in adult females and individuals rearing the young. ‘Consumption’ and ‘Tactile’ behaviors were more frequent in subadults. The hoary fox intraspecific communication is characteristic of solitary canids, but during mating season and rearing period, individuals become more ‘socialized.’ Data on courtship and mating, partnership dissolution phase, and the breakup of the family group until young dispersal, are necessary for a better understanding of intraspecific communication of the hoary fox.
... Among carnivores, olfactory signals generally play a key role in intraspecific communication (Beauchamp et al., 1976;Gorman, 1980;Brown & Johnston, 1983;Kranz, 1996;Molteno et al., 1998). In different species and under different ecological conditions, chemical signals found in feces, urine, and anal mucus can serve as reliable indicators of an individual's sex or reproductive status (Brown & Macdonald, 1985), as well as in maintaining the social organization of the group (Jorgenson et al., 1978;Brown, 1979;Macdonald, 1985;Gese & Ruff, 1997;Sillero-Zubiri & Macdonald, 1998). ...
Latrines are important sites for intraspecific olfactory communication in mammals, especially for solitary or widely distributed species. Communal latrines give visitors access to information about other visitors, notably conspecific chemical cues, even in their absence. Chemical communication has evolved to allow information transfer among individuals that, due to other ecological constraints, do not co-occur in time. Latrines can be difficult to find and monitor but provide useful information about the behavioral ecology of otters. The aim of this study was to describe the behaviors of Neotropical otters (Lontra longicau-dis, Olfers, 1818) in two communal latrines using video-camera traps. A total of 1,651 one-minute footage of otters visiting the latrines were used to elaborate an ethogram that included individuals (1) passing by, (2) rubbing, (3) scent marking , (4) scratching, (5) in vigilance, (6) smelling, (7) defecating, (8) urinating, (9) digging, (10) self-grooming, and (11) interacting with others. These results suggest that latrines are not only used by Neotropical otters to deposit feces and urine but that they also play a role in intraspecific communication. We suggest that L. longicaudis latrines function as information centers where individuals can monitor the location and activities of potential sexual partners and/or competitors.
... Little investigation has been conducted into the use of urine and faeces as chemical signals for most ursids, despite observations of urination during pedal marking and rubbing 51,52 . Urine is used by some mammals for chemical communication, including giant pandas (Ailuropoda melanoleuca) 53,54 and wolves (Canis simensis; C. lupus) 55,56 . Giant pandas and brown bears (Ursus arctos) also possess anal glands, which giant pandas use extensively for chemical communication 30,57 . ...
Scent originates from excretions and secretions, and its chemical complexity in mammals translates into a diverse mode of signalling. Identifying how information is encoded can help to establish the mechanisms of olfactory communication and the use of odours as chemical signals. Building upon existing behavioural and histological literature, we examined the chemical profile of secretions used for scent marking by a solitary, non-territorial carnivore, the brown bear (Ursus arctos). We investigated the incidence, abundance, and uniqueness of volatile organic compounds (VOCs) from cutaneous glandular secretions of 12 wild brown bears collected during late and post-breeding season, and assessed whether age-sex class, body site, and individual identity explained profile variation. VOC profiles varied in the average number of compounds, compound incidence, and compound abundance by age-sex class and individual identity (when individuals were grouped by sex), but not by body site. Mature males differed from other age-sex classes, secreting fewer compounds on average with the least variance between individuals. Compound uniqueness varied by body site and age for both males and females and across individuals. Our results indicate that brown bear skin-borne secretions may facilitate age-sex class and individual recognition, which can contribute towards further understanding of mating systems and social behaviour.
... Little investigation has been conducted into the use of urine and faeces as chemical signals for most ursids, despite observations of urination during pedal marking and rubbing 48,49 . Urine is used by some mammals for chemical communication, including giant pandas (Ailuropoda melanoleuca) 50,51 and wolves (Canis simensis; C. lupus) 52,53 . Giant pandas and brown bears (Ursus arctos) also possess anal glands, which giant pandas use extensively for chemical communication 27,54 . ...
Scent originates from excretions and secretions, and its chemical complexity in mammals translates into a diverse mode of signalling. Identifying how information is encoded can help to establish the mechanisms of olfactory communication and explore the use of odours as chemical signals. Building upon existing behavioural and histological literature, we sought to examine the chemical profile of secretions used for scent marking by a solitary, non-territorial carnivore, the brown bear ( Ursus arctos ). We investigated the incidence, abundance, and uniqueness of volatile organic compounds (VOCs) from cutaneous glandular secretions of 12 wild brown bears, and assessed whether age-sex class, body site, and individual identity explained profile variation. The average number of compounds varied by age, but not solely by sex or body site. VOC profiles varied in composition and structure by age and individual identity (when individuals were grouped by sex), but not solely by sex or body site. Individual compound uniqueness varied by body site and age for both males and females and across individuals. Our results indicate that brown bear skin-borne secretions may facilitate age-sex class and individual recognition, which can contribute towards further understanding of mating systems and social behaviour.
... Furthermore, quantity judgements seem to play an important role also in regard to intergroup conflicts over food, mates and territory (Parker 1974). Studies on lions, chimpanzees, wolves and dogs (Bonanni et al. 2011;Harrington and Mech 1979;McComb et al. 1994;Sillero-Zubiri and Macdonald 1998;Wilson et al. 2001) revealed that animals withhold their participation in intergroup conflicts over resources if the number of animals in the rival group is larger than in their own group. Given that intergroup conflicts, at least in wolves, are one of the major causes of death (see chapter 2), being able to discriminate between quantities can make a huge a difference. ...
Understanding and making sense of the physical world may involve both learning and reasoning. In the current chapter, we explore studies comparing wolves’ and dogs’ speed and flexibility in learning, object permanence and means-end understanding, as well as different aspects relating to inferential reasoning and numerical competence.No major differences emerged in wolves’ and dogs’ associative learning abilities, neither in terms of the speed of learning nor in terms of their flexibility, however in general wolves were faster decision makers than dogs. Both dogs and wolves showed an equally bad performance in other areas such as the invisible displacements in the object permanence tasks and the means-end string-pulling task. Regarding their inferential skills, there may be some suggestions that wolves’ outperform dogs, however the number of studies are limited and a more in depth exploration of this area of research is needed.More consistent differences emerged in dogs’ and wolves’ numerical competence. Overall, both species successfully distinguished between stimuli of different quantities, up to 32 items and ratios up to 0.60 - 0.80 with performance following Weber’s law. In the tasks with smaller quantities, wolves outperform dogs and their success in the sequential tasks may suggest that they base their choices at least partly on numerical information, whereas dogs might base their quantity judgements partly on perceptual features, allowing them to succeed in some tasks but not in those where this information is not perceptually available.
... Algunos estudios han encontrado que ciertas especies de hormigas (Formica xerophila) (Tanner 2010; Anner y Adler 2009); lobos (Cannis lupus) (Sillero-Zubiri 1998;Mech y Harper 2002); osos negros (Ursus americanus) (Horner 1990); y algunos primates, como chimpancés (Pan troglodytes) (Mitani 2005;Wilson et al. 2004) y grupos de seres humanos (Kelly 2005), tienen enfrentamientos violentos con grupos vecinos. Estos enfrentamientos pueden ser tan violentos que pueden causar heridas graves y desencadenar en la muerte de algunos individuos. ...
Palabras clave: Área de acción, Cebus capucinus, competencia intergrupal, isla Barro Colorado, zonas compartidas. Resumen La hipótesis de riesgo sugiere que, en especies en que los enfrentamientos entre grupos puede ser fatales, el temor de encontrarse con un grupo vecino resulta en un patrón muy particular: las áreas compartidas son evitadas. Los monos Cariblancos (Cebus capucinus) muestran un modelo similar, aunque en esta especie las agresiones intergrupales rara vez son fatales. Para probar la hipótesis de riesgo en esta especie, comparamos el comportamiento de cuatro grupos en la isla Barro Colorado, Panamá. Si la hipótesis de riesgo fuese cierta, los monos evitarían las áreas compartidas porque son peligrosas y los patrones de comportamiento de cada grupo en el centro y en el borde de sus áreas de acción serían diferentes. Encontramos diferencias significativas en los modelos de comportamiento en las
... For example, Ethiopian wolves, gray wolves, and pine martens use raised-leg urination, a behavior thought to reinforce territorial boundaries by dispersal of urinary odor plumes. Urine deposition above, rather than on, the ground may improve scent dispersal (Peters and Mech, 1975;Macdonald, 1980;Pulliainen, 1981;Alberts, 1992;Sillero-Zubiri and Macdonald, 1998). Turning to another mammalian radiation, many primate species that have evolved glands dedicated for scent deposition, including ring-tailed lemurs, mandrills, drills, and sifakas, are largely terrestrial (Delbarco-Trillo et al., 2011;Drea, 2015;Vaglio et al., 2016). ...
Aeroscapes—dynamic patterns of air speed and direction—form a critical component of landscape ecology by shaping numerous animal behaviors, including movement, foraging, and social and/or reproductive interactions. Aeroecology is particularly critical for sensory ecology: air is the medium through which many sensory signals and cues propagate, inherently linking sensory perception to variables such as air speed and turbulence. Yet, aeroscapes are seldom explicitly considered in studies of sensory ecology and evolution. A key first step towards this goal is to describe the aeroscapes of habitats. Here, we quantify the variation in air movement in two successional stages (early and late) of a tropical dry forest in Costa Rica. We recorded air speeds every 10 seconds at five different heights simultaneously. Average air speeds and turbulence increased with height above the ground, generally peaked midday, and were higher overall at the early successional forest site. These patterns of lower air speed and turbulence at ground level and overnight have important implications for olfactory foraging niches, as chemotaxis is most reliable when air movement is low and steady. We discuss our results in the context of possible selective pressures and observed variation in the foraging ecology, behaviors, and associated morphologies of resident vertebrates, with a focus on mammals. However, these data also have relevance to researchers studying socioecology, invertebrate biology, plant evolution, community ecology and more. Further investigation into how animals use different forest types, canopy heights and partition activities across different times of day will further inform our understanding of how landscape and sensory ecology are interrelated. Finally, we emphasize the timeliness of monitoring aeroecology as global wind patterns shift with climate change and human disturbance alters forest structure, which may have important downstream consequences for biological conservation.
... Costs arise as a consequence of mortality or injury (Manson & Wrangham, 1991;Plowes & Adams, 2005;Rosenbaum et al., 2016;, loss of resources, or energetic costs of fleeing. Conflicts can also bring individual and group benefits, for example, through increased access to resources or mating opportunities (Arseneau et al., 2015;Cant et al., 2002;Harris, 2010), or via group augmentation or group winner effects, because larger groups are often more successful during intergroup fights, and can therefore acquire or defend valuable resources or territories (Cassidy et al., 2015;Cheney & Seyfarth, 1987;Clutton-Brock, Gaynor, et al., 1999;Clutton-Brock, O'Riain, et al., 1999;Gros-Louis et al., 2003;Markham et al., 2012;Sillero-Zubiri & Macdonald, 1998). ...
Intergroup conflict is widespread in nature and is proposed to have strong impacts on the evolution of social behavior. The conflict–cohesion hypothesis predicts that exposure to intergroup conflict should lead to increased social cohesion to improve group success or resilience in future conflicts. There is evidence to support this prediction from studies of affiliative responses to outgroup threats in some animal societies. However, most of these studies have focused on behavioral changes over short time periods (minutes and hours after exposure to an outgroup), and hence very little is known about the dynamics and durability of responses to intergroup conflict over the longer term. We investigated this question by simulating intergroup encounters in wild banded mongooses (Mungos mungo) and measuring social behavior before, during, and after these encounters over a 5-day period. We also ran control trials with non-threatening stimuli. Banded mongooses reacted immediately to intrusion stimuli by vocalizing, grouping together, and advancing on the stimulus. In the first 5 min after simulated intrusions, we saw an elevation in grooming levels, but in the hour after exposure grooming rates declined sharply, contrary to our expectation. In the two subsequent days, grooming rates remained at this depressed rate. In control trials, the initial increase in grooming was not seen, but grooming declined compared to the longer-term time periods. Grooming changed across time, but not in the same pattern as during intrusions, suggesting that intrusions had an impact above and beyond that of the experimental setup. The dynamics of grooming responses were short lived and more complex than we initially expected. We suggest this unexpected result may be linked to the frequency of aggressive intergroup encounters in this system. As control and experimental trials were run at different times of year, future work would be needed to confirm that these relative patterns are replicable. Our results indicate short-lived impacts of outgroup threat on measures of social cohesion in this species, but cannot confirm longer-term changes.
... Scent-marking is very frequent in carnivores and many other mammals for interspecific and, mostly, intraspecific communication. Odors derived from marking with urine, saliva or feces are not only important for territory delimitation and defense (Ralls 1971;Johnson 1973;Sillero-Zubiri and Macdonald 1998), but also play a prominent role in assessing the health status of conspecifics in many mammalian species (Poirotte et al. 2017;Kavaliers and Choleris 2018;Kavaliers et al. 2020). The frequent marking behavior observed also suggests that carnivore carcass sites may concentrate more persistent infective stages excreted by urine or feces from the host than in the surrounding landscape. ...
High infection risk is often associated with aggregations of animals around attractive resources. Here, we explore the behavior of potential hosts of non-trophically transmitted parasites at mesocarnivore carcass sites. We used videos recorded by camera traps at 56 red fox ( Vulpes vulpes ) carcasses and 10 carcasses of other wild carnivore species in three areas of southeastern Spain. Scavenging species, especially wild canids, mustelids and viverrids, showed more frequent rubbing behavior at carcass sites than non-scavenging and domestic species, suggesting that they could be exposed to a higher potential infection risk. The red fox was the species that most frequently contacted carcasses and marked and rubbed carcass sites. Foxes contacted heterospecific carcasses more frequently and earlier than conspecific ones and, when close contact occurred, it was more likely to be observed at heterospecific carcasses. This suggests that foxes avoid contact with the type of carcass and time period that have the greatest risk as a source of parasites. Overall, non-trophic behaviors of higher infection risk were mainly associated with visitor-carcass contact and visitor contact with feces and urine, rather than direct contact between visitors. Moreover, contact events between scavengers and carnivore carcasses were far more frequent than consumption events, which suggests that scavenger behavior is more constrained by the risk of acquiring meat-borne parasites than non-trophically transmitted parasites. This study contributes to filling key gaps in understanding the role of carrion in the landscape of disgust, which may be especially relevant in the current global context of emerging and re-emerging pathogens.
Graphical abstract
... For example, while many species occupy home ranges with undefended boundaries, others maintain actively defended territories (Powell, 2000). In species with intense and potentially lethal intergroup competition, individuals tend to avoid areas near territorial boundaries, where they are likely to encounter neighbouring individuals (Mech & Harper, 2002;Sillero-Zubiri & Macdonald, 1998;Wrangham, Wilson & Hauser, 2007), and are more alert when moving through these locations (Kurihara & Hanya, 2018;Tórrez-Herrera et al., 2020;Wrangham, Wilson, et al., 2007). Indeed, Moorcroft et al. (1999) showed how individual coyotes' (Canis latrans) avoidance of areas with a high probability of encountering the scent marks of individuals from neighbouring pair of individuals with a hard territorial border between their home ranges; and (c) a predator with a large home range that encompassed the home ranges of multiple prey individuals. ...
Ecologists have long been interested in linking individual behaviour with higher level processes. For motile species, this ‘upscaling’ is governed by how well any given movement strategy maximizes encounters with positive factors and minimizes encounters with negative factors. Despite the importance of encounter events for a broad range of ecological processes, encounter theory has not kept pace with developments in animal tracking or movement modelling. Furthermore, existing work has focused primarily on the relationship between animal movement and encounter rates while the relationship between individual movement and the spatial locations of encounter events in the environment has remained conspicuously understudied.
Here, we bridge this gap by introducing a method for describing the long‐term encounter location probabilities for movement within home ranges, termed the conditional distribution of encounters (CDE). We then derive this distribution, as well as confidence intervals, implement its statistical estimator into open‐source software and demonstrate the broad ecological relevance of this distribution.
We first use simulated data to show how our estimator provides asymptotically consistent estimates. We then demonstrate the general utility of this method for three simulation‐based scenarios that occur routinely in biological systems: (a) a population of individuals with home ranges that overlap with neighbours; (b) a pair of individuals with a hard territorial border between their home ranges; and (c) a predator with a large home range that encompassed the home ranges of multiple prey individuals. Using GPS data from white‐faced capuchins Cebus capucinus , tracked on Barro Colorado Island, Panama, and sleepy lizards Tiliqua rugosa, tracked in Bundey, South Australia, we then show how the CDE can be used to estimate the locations of territorial borders, identify key resources, quantify the potential for competitive or predatory interactions and/or identify any changes in behaviour that directly result from location‐specific encounter probability.
The CDE enables researchers to better understand the dynamics of populations of interacting individuals. Notably, the general estimation framework developed in this work builds straightforwardly off of home range estimation and requires no specialized data collection protocols. This method is now openly available via the ctmm R package.
... Territorial behaviours, such as scent marking, vocal 40 advertisement, boundary patrols and aggression are used to establish and maintain these 41 territories (Boitani & Fuller, 2000). Demonstrating space-associated intolerance is therefore 42 often used to confirm the presence of territorial defence (Eibl-Eibesfeldt, 1970;Vine, 1973), 43 for example, through increased rates of aggression when encountering intruders in the (Gittins, 1980;Sillero-Zubiri & Macdonald, 1998;49 David P Watts & Mitani, 2001). Territorial defence may also be further influenced by the 50 resources present in the area, with greater defence of, and competition over, areas of high 51 resource quality (Johnsson, Carlsson, & Sundstrom, 2000;Pröhl & Berke, 2001). ...
Many species show territoriality, in which territory owners have exclusive or priority use of a region. In humans, tolerance of others within our space also depends greatly on our social relationships with them. This has been hypothesized as one potential driver of the evolution of long‐term, inter‐group relationships, through enabling shared access of resources and easing disputes over space.
However, extremely little is known about the importance of social relationships between neighbouring groups in non‐humans for how space is used and shared.
Using 16 years of data on the simultaneous movement and interaction patterns of 17 mountain gorilla groups, we investigated how the occurrence of aggressive and affiliative behaviour during inter‐group encounters was influenced by both their social and spatial context.
We found evidence of territorial defence, with rates of aggression increasing towards the centre of home ranges. Groups which had previously split from each other showed higher levels of affiliation during encounters with each other and experienced lower levels of aggression when within the other's peripheral home range. However, encounters within core areas of the home range consistently elicited higher aggression, regardless of the groups' history. Our findings indicate that not only are the social relationships between groups retained after they split from one another but also that these relationships enable groups to access certain areas with a reduced risk of aggression.
This suggests that reduced aggression when accessing areas within neighbours' home ranges may be an advantage for the maintenance of inter‐group relationships and a potential driver in the evolution of long‐term, post‐dispersal relationships and complex multi‐level societies.
... Because the probability of winning an encounter often depends on "the asymmetry in fighting ability" and "pay-off asymmetry" (Smith and Parker 1976), we here also examined factors potentially affecting the outcome of inter-group encounters. In many species, differences in group size can result in asymmetries in fighting abilities during inter-group encounters leading larger groups to win over smaller groups (Sillero-Zubiri and Macdonald 1998;Kitchen et al. 2004;Palmer 2004;Crofoot et al. 2008;Furrer et al. 2011;Majolo et al. 2020). Moreover, if an encounter location has been intensively used by a group, it might be of a higher value than other locations resulting potentially in a higher motivation to defend the area (Kitchen et al. 2004;Crofoot et al. 2008;Wilson et al. 2012;Brown 2013;Koch et al. 2016b). ...
When resources are limited and defensible, inter-group encounters in animals are often of aggressive nature. Individuals can participate in inter-group encounters to defend mates, infants, and food resources, but also to attract out-group individuals for additional mating opportunities. Since inter-group conflicts have mainly been studied in group-living species, we examined the mate, infant and food resource defense and mate attraction hypotheses in pair-living Javan gibbons (Hylobates moloch) in Gunung Halimun-Salak National Park, Indonesia. To this end, we investigated factors influencing male and female participation and outcome of encounters (i.e. win vs. lose). We observed 234 complete encounters between three habituated and five
unhabituated gibbon groups over 43 months, of which 72% were aggressive. Males were the main participants and they were more likely to participate when cycling females or dependent infants were present, supporting the mate and infant defense hypotheses. Males were also more likely to participate when more fruits were available,
contradicting the food resource defense hypothesis. Females participated by singing more often when they were cycling and when there were singing opponents, suggesting an advertisement function of their reproductive status through songs. The probability of winning an inter-group encounter was only higher when cycling females were present, supporting the mate defense hypothesis. The intensity of space use or aggression level had no effect on the outcome of inter-group encounters. Our results highlight that mate and infant defense are crucial for male Javan gibbons, especially in view of their pair-living system, long interbirth intervals and slow infant development.
... Many territorial species establish their home ranges with "marks." Canine species do so with urine (Sillero-Zubiri and Macdonald, 1998), and Western banded geckos (Coleonyx variegatus) establish their preferred defecation sites away from their diurnal resting sites, typically in areas that have already been marked by conspecifics (Carpenter and Duvall, 1995). However, with relatively few exceptions, fish exhibit neither discrete glands for generating such chemical markers, nor do they present readily apparent marking behavior (Liley, 1982). ...
Three types of discharge were observed to be released from captive specimens of the hedgehog seahorse Hippocampus spinosissimus: feces and two other newly discovered types. Of the latter two, one ("type 2 discharge") was a translucent mucus that was expelled from the anus and was clearly not feces; upon microscopic observation, it remained in the water column longer than feces and was more likely to adhere to artificial holdfasts. Seahorses were significantly more likely to perch on holdfasts containing this discharge (p<0.01), possibly via their detecting of its smell (i.e., olfactory behavior). Preliminary tests revealed that the active components of type 2 discharge are significantly water-soluble (p<0.05). We surmise that this discharge expulsion behavior may be the mechanism by which seahorses "mark their territory" and establish site fidelity.
... For a clearer idea of the discrimination made (numerical judgment or quantity judgement), a real-life situation study would be more apt. Both pack dogs and wolves have been shown to appropriately adjust their behaviour in inter-group conflicts, depending upon the opponent group size compared to the self-group size 33,34 . Another relevant real-life situation where keeping track of numbers may be necessary is for a mother to be aware of how many pups she has. ...
Animals in their natural environment often face situa-tions where it may be advantageous for them to be able to make decisions based on numerical or quantity discrimination. Canids like pet dogs, wolves and coy-otes have been known to have a preliminary sense of number. We tested 303 unique free-ranging dogs for seven food-choice tasks, skewed in terms of stimulus: olfactory, visual and reward obtained. The dogs pri-marily used olfactory cues in the decision-making process, rather than visual cues, to discriminate between different quantities in a context-dependent manner.
Remote monitoring of communal marking sites, or latrines, provides a unique opportunity to observe undisturbed scent marking behaviour of African wild dogs ( Lycaon pictus ). We used remote camera trap observations in a natural experiment to test behavioural scent mark responses to rivals (either familiar neighbours or unfamiliar strangers), to determine whether wild dogs exhibit the “dear enemy” or “nasty neighbour” response. Given that larger groups of wild dogs represent a greater threat to smaller groups, including for established residents, we predicted that the overarching categories “dear enemy” vs. “nasty neighbour” may be confounded by varying social statuses that exists between individual dyads interacting. Using the number of overmarks as a metric, results revealed an interaction between sender and receiver group size irrespective of familiarity consistent with this prediction: in general, individuals from large resident packs overmarked large groups more than they overmarked smaller groups, whereas individuals from smaller packs avoided overmarking larger groups, possibly to avoid detection. Monitoring a natural system highlights variables such as pack size that may be either overlooked or controlled during scent presentation experiments, influencing our ability to gain insights into the factors determining territorial responses to rivals.
Celem niniejszej pracy był szczegółowy przegląd badań naukowych nad komunikacją wizualną, dźwiękową, zapachową i dotykową (w tym komunikacją sejsmiczną) wśród różnych rzędów ssaków, przeprowadzonych w minionych latach. Skupiono się na zróżnicowaniu kontekstów komunikacji, zachowaniach związanych z porozumiewaniem się, narządach zmysłów umożliwiających komunikację oraz na sposobach przezwyciężania przez zwierzęta ograniczeń środowiskowych, które utrudniają wymianę informacji. Ponadto zwrócono uwagę na występowanie międzygatunkowej i nieukierunkowanej komunikacji u ssaków. Analiza danych literaturowych pozwoliła stwierdzić, że ssaki cechują się dużym zróżnicowaniem sposobów porozumiewania się w zależności od środowiska i trybu życia oraz wykształciły liczne adaptacje anatomiczne i/lub behawioralne usprawniające proces komunikacji, a większość interakcji społecznych zwierząt z tej gromady ma charakter multimodalny. Słowa kluczowe: Mammalia, behawior socjalny, interakcje wewnątrz- i międzygatunkowe, komunikacja, narządy zmysłów, maskowanie sygnału
Latrines are accumulations of two to several hundred faeces resulting from the repeated use of the same defecation sites by the same or several individuals. Many carnivores deposit their faeces in such dedicated latrine sites, which are often shared by several animals either from the same social group or from neighbouring territories. Although latrines are assumed to play an important role in olfactory communication, detailed knowledge of specific information exchange is still lacking. Four different categories of data are important in trying to understand the function of latrines in animal societies: (i) spatial distribution patterns; (ii) temporal usage patterns; (iii) individual visit and contribution patterns; and (iv) information content of the signal. While the spatial distribution of latrines in relation to territory boundaries, landmarks and resources has been studied in a variety of species, only a few studies concentrated on temporal variation in latrine usage. Even fewer studies provide insights into inter‐individual differences in visit and contribution patterns or the olfactory information content of latrines. In this review, we outline potential functional hypotheses for latrine use and develop a research framework for the study of latrine function. We then present three model species – European badger, Meles meles , meerkat, Suricata suricatta , and banded mongoose, Mungos mungo – for which we have detailed data for at least three of the four above‐mentioned categories, which we will use to test these hypotheses. Throughout the chapter, we review the different techniques used to collect these data in different species, discuss the limitations of using spatial data alone to test functional hypotheses, and highlight the value of a combined approach.
The function of holding territories is primarily to have access to resources like food and mates. However, it is costly in terms of energy and time investment. Solitary-living, territorial species are known to reduce these costs by being more aggressive towards unfamiliar strangers and less aggressive towards neighbors. However, in social, territorial species, neighbors can impose a greater threat than strangers. We tested whether the highly social Asiatic wild dogs/dholes (Cuon alpinus) exhibit the “nasty neighbor” or the “dear enemy” phenomena in Tadoba Andhari Tiger Reserve (TATR), Maharashtra, India. We conducted scat translocation experiments where we presented fresh scats collected from unique donor groups to a resident dhole group and tested the type and the intensity of behavioral response (duration) to the stimulus. Dholes responded differentially to the two treatments suggesting they exhibit neighbor-stranger discrimination. Overall, strangers elicited a stronger response with longer duration and larger packs were less likely to respond to the stimulus than smaller packs. Differences found between categories of dhole scent marks establish the importance of olfactory communication, especially “counter-marking” in the species. Within recipient packs, individual status affected the response to trials wherein the alpha pair reacted more intensively to strangers than others. Our study provides experimental evidence to demonstrate that dholes exhibit the “dear enemy” phenomenon.
Significance statement
Animals defend territories from other members of their own species, but intrusions are commonplace in the wild. Different intruders may pose different levels of threats, and hence, intruders are treated differentially to minimize the energetic costs of territorial defense. In some animals, neighbors with well-established territories may become less aggressive towards each other. This is known as the dear enemy effect. By contrast, at times neighbors may represent a greater threat than strangers which is known as the “nasty neighbor” effect. We experimentally show that dholes exhibit the dear enemy phenomenon by responding more intensively to strangers than familiar neighbors. We show how response varied based on hierarchy in a pack as well as the pack sizes. Furthermore, we found that, both in core as well as buffer areas of their own territory, this relationship was consistent.
Understanding the use of space by endangered African wild dogs (Lycaon pictus) can contribute to their conservation because persecution by livestock farmers is a major cause of mortality when wild dogs range outside protected wildlife areas. Scent-marking is likely to be a key mechanism by which African wild dog packs organise their mutual use of space, and here, we report the discovery that African wild dog packs repeatedly shared a scent-marking latrine. We present the first systematic records of scent communication between packs of African wild dogs. Camera trapping for 13 months recorded four wild dog packs in northern Botswana repeatedly scent-marking with urine and faeces at a latrine where two dirt roads crossed a large game trail, in the overlap zone of two of the packs’ home ranges. This site was visited by wild dogs at a mean interval of 12.2 days, with a mean of 10.3 days between consecutive visits by different packs, and a mean of 28.7 days between consecutive visits by the same pack. Dominant dogs scent-marked every time they visited this site for a minute or longer. Sniffing and countermarking of scent-marks from previous visits showed that this shared marking site acted as a bulletin board, with 12 exchanges of information between packs over a period of 13 months.
Significance statement
African wild dogs are endangered large carnivores, whose populations suffer continual attrition from lethal conflict with livestock owners. Deterring wild dogs from leaving protected wildlife areas will reduce this conflict-related mortality. All terrestrial mammals mark their home ranges with scent, and using artificial scent-marks to simulate African wild dog home range boundaries along protected area borders has the potential to reduce conflict killings by deterring the dogs from leaving the protected areas. Our discovery of multiple African wild dog packs scent-marking at a persistent, shared latrine, where scent-marking depended on sex and social status, is a breakthrough in our understanding of inter-pack communication in this endangered species and a key step towards developing artificial home range boundary markers that will deter them from leaving protected wildlife areas.
Loggerhead sea turtles (Caretta caretta) are currently listed as vulnerable, with a decreasing population trend, by the International Union of Conservation of Nature. From 2015 to 2019, coyotes (Canis latrans) depredated 24.12% of loggerhead nests on the night they were laid on South Island beach at the Tom Yawkey Wildlife Center, near Georgetown, SC, resulting in an estimated 3,816 eggs lost each year. Over that time, a South Carolina Department of Natural Resources Turtle Technician Team patrolled the beach at dawn every morning to cage and catalog loggerhead nests and eggs but were unable to cost-effectively protect the nests the night the eggs were laid. To test a new method to dissuade coyote depredation, we used dispensers filled with gray wolf (Canis lupus) urine to simulate wolf activity on seven sections of the beach and left seven sections untreated as controls. We observed a significant reduction in depredation rates where urine was present relative to control areas (G-test adjusted with the Williams correction, G=5.749, df=1, p=0.0165). The results suggest this may be an example of exploitative competition in the absence of interference competition. With daily teams already patrolling the beaches, using wolf urine as a deterrent could be an inexpensive, non-invasive way to reduce coyote depredation on loggerhead and other sea turtle nests elsewhere.
The spatiotemporal distribution of parasites in ecosystems is heterogeneous. High infection risk is often associated with aggregations of animals around attractive resources. Here, we explore the behavior of potential hosts of non-trophically transmitted parasites at mesocarnivore carcass sites. We used videos recorded by camera traps at 56 red fox ( Vulpes vulpes ) carcasses and 10 carcasses of other wild carnivore species in three areas of southeastern Spain. In general, scavenging species, especially wild canids, mustelids and viverrids that display rubbing behavior, were more exposed to infection risk at carnivore carcass sites than non-scavenging and domestic species. The red fox was the species that most frequently contacted carcasses and marked and rubbed carcass sites. Foxes contacted heterospecific carcasses more frequently and earlier than conspecific ones, and close contact was more frequently observed at heterospecific carcasses. Thus, foxes seemed to avoid contacting carcasses in those periods and at carcass types of maximum risk of acquiring parasites. Overall, our results suggest that infection risk at carnivore carcass sites may take place mainly for visitor-carcass contact or contact with feces and urine rather than direct contact between visitors. Moreover, contact events between scavengers and carnivore carcasses are far more frequent than consumption events, which indicates that scavenger behavior is more constrained by the risk of acquiring meat-borne parasites than non-trophically transmitted parasites. This study contributes to filling key gaps in understanding the role of carrion in the landscape of disgust, which may be especially relevant in the current global context of emerging and re-emerging pathogens.
Synopsis
Female–female reproductive suppression is evident in an array of mammals, including rodents, primates, and carnivores. By suppressing others, breeding females can benefit by reducing competition from other females and their offspring. There are neuroendocrinological changes during suppression which result in altered behavior, reproductive cycling, and communication. This review, which focuses on species in Rodentia, explores the current theoretical frameworks of female–female reproductive suppression, how female presence and rank impacts reproductive suppression, and some of the proposed mechanisms of suppression. Finally, the understudied role of olfactory communication in female–female reproductive suppression is discussed to identify current gaps in our understanding of this topic.
Chemical communication is important for many species of mammals. Male brown bears, Ursus arctos , mark trees with a secretion from glands located on their back. The recent discovery of pedal glands and pedal-marking at a site used for tree-rubbing led us to hypothesize that both types of marking form part of a more complex communication system. We describe the patterns of chemical communication used by different age and sex classes, including differences in the roles of these classes as information providers or receivers over four years at a long-term marking site. Using video recordings from a camera trap, we registered a total of 285 bear-visits and 419 behavioral events associated with chemical communication. Bears visited the site more frequently during the mating season, during which communication behaviors were more frequent. A typical visit by male bears consisted of sniffing the depressions where animals pedal mark, performing pedal-marking, sniffing the tree, and, finally, rubbing against the trunk of the tree. Adult males performed most pedal- and tree-marking (95% and 66% of the cases, respectively). Males pedal-marked and tree-rubbed in 81% and 48% of their visits and sniffed the pedal marks and the tree in 23% and 59% of visits, respectively. Adult females never pedal marked, and juveniles did so at very low frequencies. Females rubbed against the tree in just 9% of their visits; they sniffed the tree and the pedal marks in 51% and 21% of their visits, respectively. All sex and age classes performed pedal- and tree-sniffing. There were significant associations between behaviors indicating that different behaviors tended to occur during the same visit and were more likely if another individual had recently visited. These associations leading to repeated marking of the site can promote the establishment of long-term marking sites. Marking sites defined by trees and the trails leading to them seem to act as communication hubs that brown bears use to share and obtain important information at population level.
Nilgai antelope (Boselaphus tragocamelus) are an exotic ungulate species in Texas.
Native to India, Nepal, and Pakistan, nilgai have expanded into much of coastal southern Texas and northeastern Mexico since their introduction in 1924–1949. The presence of nilgai in Mexico and South Texas has complicated the eradication of cattle fever ticks (CFT; Rhipicephalus annulatus and R. microplus). Cattle fever ticks can transmit bovine babesiosis to cattle, a serious economic threat to the U.S. cattle industry. With CFT quarantine areas established in South Texas, ranches with infested cattle must comply with extensive eradication requirements. Wildlife can hinder eradication efforts because white-tailed deer (Odocoileus virginianus) and nilgai are alternative hosts for CFT. Control methods, such as acaricide-treated baits, are available for deer. Nilgai do not respond to bait, which is a major challenge for controlling the spread of CFT. One unique aspect of nilgai ecology is their use of latrines, or repeated defecation at a localized site. In addition, nilgai are not impeded by standard livestock fencing, and often push under fences at well-established crossing sites. The existence of these repeatedly visited areas present an opportunity for CFT treatment through application of acaricides using remotely
iv activated sprayers. With limited information on nilgai ecology, there is pressure to understand nilgai latrine and fence crossing behavior to design efficient CFT treatment measures. I analyzed the density, size, activity, and placement of nilgai latrines. I used trail cameras to assess frequency, time of day, sex, and age of nilgai that used latrines and all animals that used fence crossings. Also, I used genetic markers to determine how many individual nilgai use latrines. Knowledge of nilgai movement and behavior will help identify areas to target with remotely activated acaricide sprayers. The results of this study will have important implications for the development of treatment methods for eradication of CFT in the U.S
Although there are recent claims of a lack of evidence of self-consciousness in many tested species, the ability to recognize oneself in a mirror, which seems an exceedingly rare capacity in the animal kingdom, may not be the only way to check for animal self-awareness (i.e. the capacity to become the object of your own attention). A new testing approach, based on a different sensory modality (such as the sniff-test for self-recognition, STSR), recently proved to be effective with dogs. We applied this sniff test to a group of four captive grey wolves, living in male-female couples in two different enclosures at the Wolf Park in Indiana, USA. In this preliminary study, wolves showed some signs of the ability to recognize themselves through the “olfactory mirror” and exhibited some clues of mark-directed responses, particularly scent-rolling, which may shed more light on this still unclear behavior and represent a sort of olfactory equivalent to passing the original mirror test.
Carnivores rely heavily on scent to communicate with conspecifics. Scent glands located on the underside of the feet provide an especially efficient way of leaving a scent trail. Although domestic dogs (Canis familiaris) are well-known for their olfactory abilities and scent marking behaviours, their use of pedal scent for communication remains unknown. We studied the reaction of intact dogs of both sexes to male and female pedal scent as well as a control sample of scent taken from the ground, using sniffing time and nostril usage as an indicator of interest level and emotional valence. In male subjects, only the sniffing duration for other males differed from the control samples, with no clear difference detected between male and female scent. Females showed no difference in the sniffing duration for any sample type. Conversely, male nostril use did not differ between the sample types, whereas females demonstrated a right nostril bias when sniffing the scent from other females and a left nostril bias when sniffing the control. We have shown that dogs recognize scent taken from the pedal glands from other dogs, although the extent to which they use this information to determine the sex of the scent depositor remains unclear.
The dominant social-evolutionary paradigm implicitly equates social actions and behaviors causing associations by extrapolating from models of social actions to explain behaviors affecting association. This extrapolation occurs when models of helping behavior are applied to explain aggregation or fusion, and when models of discriminatory helping behavior are applied to explain discriminatory segregation or discriminatory rejection. Here, I outline an alternative theoretical approach that explicitly distinguishes a social action as a helping or harming behavior, and an association as the context for a social action. Based on this distinction, I define a list of terms that allows a classification of association phenomena and the conceptual framework necessary to explain their evolution. I apply the resulting theory, which I call “association theory,” to identify a series of steps common to major and minor transitions in social evolution. These steps include the evolution of association, the evolution of differential treatment, the evolution of association preference, and the evolution of genetic kin recognition. I explain how to measure the parameters of association theory and I apply the theory to test Hamilton’s rule. I evaluate the evidence for association theory, including how it resolves anomalies of a former paradigm. Finally, I discuss association theory’s assumptions, and I explain why it may become the dominant framework for analyzing social evolution.
We studied life history strategies in the Eurasian beaver (Castor fiber), a territorial, monogamous, long-lived mammal, to increase our understanding of the mechanisms and trade-offs affecting the onset of natal dispersal, mate change, spatial movement patterns, and the duration of territory occupancy.
The mean age at dispersal in our study area was 3.4 years, with some individuals remaining within their natal family group until age 7. Subordinates delayed dispersal with increasing age of the same-sex parent. This suggests that either parents are more tolerant towards their offspring at an increasing age, or that subordinates can perceive senescence and thus ”queue” in the natal territory to take it over after the death of the parents. In addition, individuals were more likely to disperse with increasing age and at lower population densities. This suggests that subordinates gain competitive abilities with increasing age, and that they can perceive changes in population density. We found that subordinates often conducted extra-territorial movements, which lasted longer compared to extra-territorial movements by territory holders (dominants), and they usually intruded into multiple territories, which likely is a mechanism to detect a suitable timing for dispersal by gaining knowledge on available territories and population density fluctuations.
Further, we found that mate change in beavers was non-adaptive, most likely caused by the intrusion of a younger, incoming individual replacing the same-sex territory holder, and to a lower degree by the accidental loss of a partner. We then investigated spatial movement patterns of dominant beavers, and found that there was a territory size-dependent trade-off between patrolling and foraging: beavers in smaller territories had reduced costs of patrolling (they travelled at lower speed), but stayed further from the shore when foraging, possibly due to resource depletion. Beavers in smaller territories also conducted more extra-territorial movements, likely to assess possibilities for territory expansion. Additionally, older beavers spent more time on land and close to territory borders suggesting a behavioral change with age due to senescence or experience.
The duration of territory occupancy ranged between 1 and 11 years (mean ± SD: 6.2 ± 2.8 years), and was a predictor for the lifetime reproductive success of an individual. Beavers that delayed dispersal and established in intermediate-sized territories occupied them for longer compared to younger dispersers and individuals establishing in smaller or larger territories. This suggests that an individual should await its physical and behavioral maturation before the acquisition of a territory, and demonstrates that intermediate-sized territories follow the optimization criterion, ensuring sufficient resource availability and decreased costs of territorial defense at the same time.
The high population density in our study area is likely a major factor affecting many of the observed patterns, leading to an intense competition for territories, in effect causing delayed dispersal, non-adaptive mate change, and is driving spatial movement patterns related to patrolling and resource availability.
Phonosemantics is a school of thought which believes that each sound or phoneme carries a specific psychological impression allotted by nature. And these psychological impressions were used to evolve different languages. Work has been done on this ground, but there is still scope for further research into the subject. The paper presents a new hypothesis, explaining the psychological representations of all the important IPA alphabets. The paper proposes a model of psychological mind, on which all the basic phonemes are placed, enabling us to understand the basic relationship between psychological semantic values and their phonetic values. To prove the correctness of the allocation, the paper applies these semantic features to 245 words of different languages, along with some additional evidences. The paper resolves the confusion regarding the same name for different objects, different names for the same object, the question of arbitrariness, and other queries raised by modern linguists.
In social animals, areas where the home ranges of neighboring groups overlap are often underused. The Risk Hypothesis posits that the costs of intergroup conflict create a “landscape of fear,” discouraging the use of such shared areas. To test this hypothesis, we observed the behavior of white-faced capuchins (Cebus capucinus) in central vs. peripheral areas of their home ranges. If capuchins perceive areas of home range overlap as “risky,” we predicted they would change activity budgets, vocalization rates, and foraging behavior in these areas. A spatially explicit behavioral comparison based on nearly 100 h of focal follows revealed that capuchins socialize less in the periphery (vs. the center) of their home range. Time spent resting, foraging, and engaging in vigilance, as well as vocalization rates, varied in consistent ways across all four study groups, but these differences did not reach statistical significance. Fruit trees near range borders (vs. the center) contained more ripe fruit, and groups spent more time in these trees, with more individuals entering to feed and consuming more fruits. However, capuchins did not alter their foraging behavior in potentially risky peripheral areas in a manner consistent with predictions of optimal foraging theory: intake rates at patch departure were not significantly lower and groups depleted trees to a greater extent along the periphery vs. in the center of their range. These results suggest that while peripheral areas are perceived as risky and this “landscape of fear” contributes to behavioral changes, they also provide resources whose value may outweigh the cost of intergroup encounters.
The Canidae are successful, being a widespread, abundant, speciose, and adaptable family. Several canids in particular have recently experienced rapid expansions in range and abundance, with similar situations mirrored on several continents by different species. Despite extreme behavioral diversity between and within species, monogamy is a common denominator in canid societies. In this review, we ask why canids are monogamous and how monogamy is related to their success. We begin with an overview of canid social monogamy, describing the pair bonding, paternal care, and often alloparental care that is characteristic of the family, and discuss theories on the evolution of mammalian social monogamy. We discuss why and how monogamy is maintained in canids, either voluntarily or enforced, and how ecological conditions influence either the functional advantages of monogamy or ability for enforcement and thus whether social monogamy is maintained. Social monogamy does not necessitate exclusive mating and many canids exhibit extra-pair paternity. We consider the costs and benefits of extra-pair mating for male and female canids and how ecological conditions can shift this cost/benefit balance and thus affect its prevalence. Monogamy may be responsible for many of the unusual canid reproductive characteristics through facilitating alloparental care and monogamy enforcement, and the domestic dogs' departure from monogamy supports our interpretation that it is an adaptation to resource availability. In asking whether monogamy is responsible, at least in part, for their success, we propose the monogamy as pro-cooperative hypothesis, suggesting four characteristics have contributed to canid success: (1) ecological flexibility, (2) high mobility, (3) high reproductive rates, and (4) sociality/cooperation, with the latter two being consequences of monogamy. These four interconnected traits enhance one another and it is their combination, with monogamy at its foundation enabling cooperative sociality and thereby enhanced reproduction and survival, that together comprise the formula of canid success.
Among many hypotheses in the literature that explain overmarking in mammals, most studies favour a sexual selection hypothesis. However, results in the literature are conflicting. In this study, we tested two hypotheses that could explain overmarking by males: (i) as a part of sexual selection, more specifically to mask scent of receptive females and (ii) as a form of communication serving to aid group cohesion. We observed each of the three zebra species in eight different herds at four zoos. In total, we recorded 1395 eliminations (760 defecations, 635 urinations) performed by 78 individuals including 8 stallions. Stallions investigated 248 eliminations and overmarked 124. The rate of overmarking by stallions was higher than those of all other sex and age categories. Stallions of all species overmarked all age and sex categories, except Grévy’s zebra stallions did not overmark foal eliminations. In contrast to our first hypothesis, when attracted to the elimination, stallions overmarked non-oestrus females more often than oestrus ones. Thus, our results did not support the hypothesis that overmarking by males has a sexual selection function, but it could be explained by the group cohesion hypothesis. Based on our results, it seems that overmarking by equid males plays a greater role in intra-specific communication than in intra-sexual competition. In addition, this behaviour might play different roles in different species based on their social organisation.
Significance statement
Overmarking is ubiquitous among terrestrial mammals; however, the function of this behaviour has not been fully explained. In addition, previous studies came to differing conclusions. In this study, we tested two hypotheses possibly explaining overmarking by adult males in three equid species. We found that adult males overmarked at a much higher rate than individuals of all other sex and age categories. In contrast to many other studies, our results did not support the hypothesis that overmarking by males has a sexual selection function, but it could be explained by a group cohesion hypothesis.
Births of the Ethiopian wolf (Canis simensis) in the Bale Mountains of Ethiopia coincided with the end of the rainy season and were synchronized among adjacent packs. During any given year, births in packs of one subpopulation coincided closely but were out of synchrony with those in a nearby subpopulation. From this we infer the existence of a mechanism for synchronizing breeding locally. We suggest that mating synchrony helps breeding females to reduce the capacity of dominant males to intersperse, monopolizing them with philandering.
Between October 1991 and February 1992, 41 of 53 known adult and subadult Ethiopian wolves (Canis simensis) in five adjacent packs in the Bale Mountains National Park, Ethiopia, died or disappeared. Brain smears from two carcasses were positive for rabies by the immunofluorescence test, and rabies virus was isolated from the brains by mouse inoculation. Based on monoclonal antibody tests on the mouse brains, we identified the virus as a minor variant of the serotype 1 rabies viruses found in domestic dogs and wild canids of Africa. Sera from two of 15 Ethiopian wolves had rabies virus neutralizing antibody.
Trespassing and defence on bird breeding territories can be due to males seeking extra-pair copulations with fertile females (the sperm competition hypothesis), to non-territory holders prospecting for potential vacancies (the non-territory holder hypothesis), or to conspecifics unaware of territory boundaries or seeking superior territories during the territory establishment phase of the breeding season (the territory establishment hypothesis). Nine predictions on the variation in trespassing on territories in relation to season, time of day, participating sex, spatial origin of intruders, social dispersioin, number of broods, nest predation rate, breeding synchrony, and breeding habitat together fully separate the three alternative hypotheses. Existing evidence to a large extent supports the sperm competition hypothesis.
The Ethiopian wolf (Canis simensis) is a rare and endangered carnivore found in only a few mountain ranges of the Ethiopian highlands. We studied its diet and feeding behavior in Bale Mountains National Park, Ethiopia, from 1988 through 1992. Observations of foraging behavior (n = 380) and scat analysis (n = 689) suggested that the Ethiopian wolf specializes in eating rodents. Rodents accounted for 96% of the prey occurrences and 97% volume in the droppings. The giant molerat (Tachyoryctes macrocephalus) was the main food item, followed in importance by three species of rats (Arvicanthis blicki, Lophuromys melanonyx, and Otomys typus). Ethiopian wolves foraged solitarily throughout the day, but occasionally small packs ( ltoreq 6) hunted hares, young antelopes, and sheep. During foodchoice experiments, wolves significantly preferred Tachyoryctes to Arvicanthis and Lophuromys, Arvicanthis to Lophuromys, and either of them to Stenocephalemys, which was invariably discarded. Lepus starcki was preferred to any of the species of rats. The contribution of different species of prey to the diet of the Ethiopian wolf correlated with abundance of prey.
The relationship between urine-marking and caching was studied in two captive groups of wolves (Canis lupus). It was found that urine-marking never occurred when a cache was stocked, rarely occurred during later investigations if some food was still present, but usually occurred soon after the cache was emptied. The animal marking an empty cache was often not the one which had exploited it. Once an empty cache was marked it received little further attention, as opposed to caches that were empty but not urine-marked. These results suggest that urine-marking may enhance foraging efficiency in wolves by signalling that a site contains no more edible food despite the presence of lingering food odors.
The eleven different functions for which mammals use urine marking are reviewed in this paper, and the urine marking behavior of the red fox (Vulpes vulpes) is described in detail. A new hypothesis is advanced that urine marking may serve as a "book keeping system" in the red fox's scavenging behavior. Foxes consistently investigate and urine mark inedible food remnants (e.g., bones, bird wings, and dried out pieces of hide). When a fox re-investigates a marked remnant, the urine mark signals "no food present," and the fox investigates this object for only a brief period of time. This use of urine marking may increase the efficiency of its scavenging behavior, i.e. more food-items found per hour of scavenging. This efficiency may be particularly important during periods of food shortage. The hypothesis is tested in three different experiments, using free-ranging red foxes as subjects. Experiment I establishes that fox do urine mark food remnants. Experiment II shows that foxes investigate for a significantly shorter period of time (P<0.001) food remnants exhibiting both the odor of food and the odor of urine as compared to remnants exhibiting just the odor of food. Experiment III suggests that there a hierarchy of stimuli which determines different responses in the fox's scavenging behavior. The experiments also suggest that there is a degree of social behavior in the scavenging activities of red foxes. Foxes appear to use each other's urine marks to increase the efficiency of their scavenging behavior. Thus this study definitely support LEYHAUSEN'S (1965) statement that the social life of solitary animals is frequently more complex than we realize. Solitary species probably show many ingeniously adapted mechanisms for occupying niches where highly social species could not be maintained. The social evolution and ecological advantages of solitary species deserve to be the focus of future research.
The wolf (Canis lupus) is a wide-ranging social carnivore with a complex spatial organization (MECH, 1972; 1973). The precise manner in which this organization is maintained is unknown, but territory advertisement using olfactory and acoustic modes seems to be involved. The acoustic mode includes primarily howling. Within a wolf pack, howling may be useful to reassemble separated members (MECH, 1966; THEBERGE & FALLS, 1967), and may communicate information on individual identity, location, and other behavioral and environmental contingencies (THEBERGE & FALLS, 1967). Between packs, however, howling may serve to advertise territory, communicating the locations of packs and thus minimizing contact between them (JOSLIN, 1967). The objective of the present study was to determine the possible role of howling in territorial maintenance by investigating the responses of wolves in northeastern Minnesota to simulated wolf howling.
The present paper presents a first order description of the precopulatory behavior of the golden jackal (Canis aureus syriacus) without using emotionally-toned words. The coarse structure of this behavior which extends over 4 months prior to copulation is described. During this time, jackals roam the fields in pairs, each pair in a particular area. From time to time they perform certain series of actions while circling each other in a specific manner. The term "T-sequence" is used for this behavior which might be defined as precopulatory. A detailed fine-grain description of selected actual sequences of four captive pairs and three wild pairs is presented. Common features and variation in performance, with special emphasis on the latter, are summarized. Precopulatory behavior of jackals might be viewed as a complex of three groups of events superimposed on one another: the group of events which constitute the T-sequences (such as circling, standing perpendicularly to the mate, putting the head on the mate's back, etc.) is superimposed on a group of patterns which are performed during the first phase of precopulatory behavior - sniffing the ground, urination and scraping. Later, a third group of patterns is superimposed on the first two groups: this group includes the male licking the female's vulva, the female mounting the male and other patterns. At this stage, the frequency of appearance of patterns of the first two groups decreases gradually; the male starts to mount the female, and a few days later copulations follow. Variation in performance was found in the following acts: 1) In certain pairs the male always forms the top of the T during T-sequences, in others the female, and in still other pairs both mates take turns at forming either the top or the base of the T. Relative body position during T-sequences is in correlation with the distribution of events between the mates. It also affects the time of onset of the week of copulations. 2) Some "agonistic" patterns were observed during T-sequences only in captivity. 3) Certain behavior patterns are performed by some pairs but not by others. 4) Some behavior patterns are performed in different "styles" by different individuals. The performance of T-sequences is related to the following factors: a) sequential relation of events to copulation, b) time of day, c) change in environment, d) howling, e) duration of pair bond, f) individual differences. Motivational models as well as quantitative analysis were avoided, since the variability of the material calls for the development of special methods for fine-grain analysis. This material deserves phenomenological treatment, in the sense that regularity should be looked for first in the structure of concrete specific behavior sequences, and only then in the behavior in general.
Otters (Lutra lutra) deposit feces as scent marks (“spraints”) throughout their range, and observations on this behavior in Shetland were used
to test the hypothesis that carnivores in group ranges use scent marking to signal priority of use of resources to other group
members. Sprainting was seasonal (high rates coinciding with low prey availability), and there was no significant, overall
difference in sprainting rates between otters of different sex or status. There were no concentrations of spraints near group
territorial boundaries. Sprainting was associated with the beginning of feeding bouts, as well as with the utilization of
other resources, such as fresh water and dens (“holts”). More than 30% of spraints were deposited in places that flooded within
hours, and the spraints were functional only for a short time. It is argued that the temporal pattern of use and subsequent
replenishment of resources makes it advantageous for otters to signal to other group members when they are exploiting a “patch”
and for other members to avoid resources already partly depleted by a prior arrival. With such a signaling system there is
no need for actual aggressive encounters to reinforce the message of scent marking. Sprainting could be the mechanism for
the observed spaced-out use of resources among the inhabitants of a group territory.
During two studies that investigated the responses of wolf packs to either human simulations or pre-recorded playbacks of wolf, Canis lupus, howling, single adult wolves from five different packs approached my location and howled on a total of six occasions. The howls uttered by these close-approaching wolves were significnatly deeper in pitch than comparable samples of howls recorded from animals that did not approach. In addition, howls of two of the five animals differed in structure from most of the other howls recorded during both studies. These close-approach howls were characterized by the presence of harmonically unrelated frequency sidebands near the end of the howl. This feature was rate in howls recorded during occasions when wolves kept their distance. These results indicate that the structure of wolf howling during aggressive interactions with strange wolves follows Morton's (1977) motivation-structural rules, which state that natural selection will favour the use of low-frequency, harsh sounds by hostile animals. This relationship follows from the physical constraints of vocal production: animals of larger size can produce sounds of lower pitch and harsher tonal quality. As body size is a primary determinant in the outcome of aggressive interactions, vocalizations signalling size (i.e.low-pitched, harsh sounds) will be of selective value for individuals engaged in aggressive interactions.
The Passive Range Exclusion (PRE) Hypothesis provides a mechanism whereby species that rest or breed in communal residences, but forage independently on dispersed food items, may avoid entering the core home ranges of neighbouring groups. A stochastic simulation shows that as the occupants of a communal residence travel outwards to feed, their activities create a gradient in food availability. Food closest to the point of origin tends to be discovered first and at the highest rate. As the foraging period continues, the probability of encountering unexploited food increases with distance from the residence. Areas of relatively high food availability persist as ridges between neighbouring communal residences. The simulation predicts that once such a gradient is established, a strategy of preferential feeding in these areas optimize food intake. Feeding excursions deep into neighbouring ranges are disadvantageous because areas of lower food availability are encountered and travel times back to the home residence become longer. The observed reluctance of individuals to forage close to neighbouring residences can therefore be explained partly or wholly as a result of exploitation competition and feeding optimization, without necessarily invoking territorial arguments about interference competition and conflict avoidance.At lower forager and food patch densities the simulation indicates that the gradient is insufficient to award significant benefit to border feeding. Hence border feeding strategies and the range exclusion that results should diminish as food or forager densities decrease. We use the European badger (Meles melesL.) as a test case for the hypothesis and show that exploitation competition between groups may be an important factor in shaping this species' home ranges.
Yearling male song sparrows Melospiza melodia on Mandarte Island, British Columbia, were either territorial or nonterritorial. Some territorial yearlings failed to gain mates. Mated yearlings with territories and floaters were much more common than unmated yearlings with territories. Floaters made up a higher proportion of the population in years of high population density. Unmated territorial birds accounted for a higher proportion of all yearling males at low population densities. Most floaters and unmated territorial yearlings remained unmated during their first breeding season. Floating males were more likely to disappear from the island after the 1st year of life. Nearly all birds that survived to 2 yr of age defended territories and bred. Birds that were floaters as yearlings and later gained a territory did not reproduce better in later life than birds that acquired territories as yearlings. Males that obtained territories and mates as yearlings thus raised more than twice as many breeding offspring during their lifetimes. Yearling territorial males without mates survived well but did not breed more successfully than floaters over their life spans. -from Authors
Radio-equipped red foxes (Vulpes vulpes) on the Cedar Creek area in Minnesota were spatially distributed, with individual families occupying well defined, nonoverlapping, contiguous territories. Territory boundaries often conformed to natural physical boundaries and appeared to be maintained through some nonaggressive behavior mechanism. Individual foxes traveled extensively throughout the family territory each night. Fox territories appeared to range from approximately 1 to 3 square miles in size, dependent largely on population density. Red foxes used a sequence of dens to rear their pups, and the amount and location of food remains at individual dens changed as the pups matured. The denning season was divided into pre-emergence, confined-use, and dispersed-use periods of 4 to 5 weeks each. Remains of adult waterfowl were collected at rearing dens on six townships in three ecologically different regions of eastern North Dakota. Remains of 172 adult dabbling ducks and 16 adult American coots (Fulica americana) were found at 35 dens. No remains from diving ducks were found. The number of adult ducks per den averaged 1.6, 5.9, and 10.2 for paired townships in regions with relatively low, moderate, and high duck populations, respectively. Eighty-four percent of the ducks were females. The species and sex composition of ducks found at dens during early and late sampling periods reflected the nesting chronology of prairie dabbling ducks. Occupied rearing dens were focal points of red fox travel, and the locations of dens may have had considerable influence on predation. Thirty-five of 38 dens found on the six township study areas were on pastured or idle lands. The distribution of rearing dens on the Sand Lake and Arrowwood national wildlife refuges suggested that, on these areas, fox dens were concentrated because of the topography and land-use practices.
Data were colleted on the scent-marking patterns of radio-collared and visually identifiable tigers for 4 years in Royal Chitwan National Park, Nepal. Five categories of marking were recorded: urine spraying; scraping with deposits of urine faeces, and anal gland secretions; clawing; cheek rubbing; and vegetation flattening. Urine spraying and scraping were the predominant forms of marking in this population. Tigers marked more heavily at territorial boundaries than in the interior of territories. Furthermore, in border areas marks were highly clumped at contact zones where major routes of travel approached territorial boundaries. This pattern appears to be a result of the density of vegetation which channels travel. The intensity of marking in these zones represented a higher frequency of marking rather than an increase in time spent in these areas. Marking was most intensive when tigers were establishing territories, and animals on adjacent territories appeared to mark in response to each other. Females marked intensively just prior to oestrus; this behaviour was reduced during oestrus. Males marked more frequently when females were in oestrus than during other stages of the females' cycle. A model is proposed where an odour field signals the risk of encountering a conspecific, thus allowing animals to compare the costs of possible encounters with the benefits of use of a given area.
Seven major types of sampling for observational studies of social behavior have been found in the literature. These methods differ considerably in their suitability for providing unbiased data of various kinds. Below is a summary of the major recommended uses of each technique: In this paper, I have tried to point out the major strengths and weaknesses of each sampling method. Some methods are intrinsically biased with respect to many variables, others to fewer. In choosing a sampling method the main question is whether the procedure results in a biased sample of the variables under study. A method can produce a biased sample directly, as a result of intrinsic bias with respect to a study variable, or secondarily due to some degree of dependence (correlation) between the study variable and a directly-biased variable. In order to choose a sampling technique, the observer needs to consider carefully the characteristics of behavior and social interactions that are relevant to the study population and the research questions at hand. In most studies one will not have adequate empirical knowledge of the dependencies between relevant variables. Under the circumstances, the observer should avoid intrinsic biases to whatever extent possible, in particular those that direcly affect the variables under study. Finally, it will often be possible to use more than one sampling method in a study. Such samples can be taken successively or, under favorable conditions, even concurrently. For example, we have found it possible to take Instantaneous Samples of the identities and distances of nearest neighbors of a focal individual at five or ten minute intervals during Focal-Animal (behavior) Samples on that individual. Often during Focal-Animal Sampling one can also record All Occurrences of Some Behaviors, for the whole social group, for categories of conspicuous behavior, such as predation, intergroup contact, drinking, and so on. The extent to which concurrent multiple sampling is feasible will depend very much on the behavior categories and rate of occurrence, the observational conditions, etc. Where feasible, such multiple sampling can greatly aid in the efficient use of research time.
A study of spotted hyenas in the Serengeti revealed that Ss regularly left their clan's territory to feed on the nearest migratory herds (commuting trips). Commuting locations matched the movements of the migratory herds throughout the year. Commuters appeared to minimize contact with resident clans and use areas where they were assured of locating migratory herds. The proportion of clan members commuting declined as prey abundance in the clan's territory increased. Territories were visited by nonresidents (commuters) throughout the year, but the number of foraging commuters increased substantially when large migratory herds entered a territory. During encounters between residents and intruders, residents adjusted their behavior according to the context of the encounter: Residents ignored commuters in transit, responded aggressively to commuters at kills, and engaged in prolonged clashes with neighboring clans. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
The distribution of otter dens (holts) and otter droppings (spraints) which also function as scent markers, is described for an area of coast in north-west Scotland, and some observations are presented of the otters' movements and foraging. Otter holts were spaced out at an average distance of 11 km, and spraints were concentrated around the holts. The foraging areas were probably used communally, and the difference between this utilization and that observed elsewhere is discussed.
Brown hyaenas scent mark by making latrines and depositing onto grass stalks two distinct secretions produced in their anal pouch. The latter behaviour is called pasting. Pastings are found spaced throughout a territory but mainly in the interior where the hyaenas spend most of their time. Latrines are clumped near to, but not along, the border. Computer analyses show that intruders encounter scent marks very soon after entering a territory. Comparison with other species indicates that the length of border to be marked by each individual in a group is the important factor in determining whether they mark throughout the territory or just along the border.
African wild dogs were studied from 1967 to 1978 on the Serengeti Plains in northern Tanzania. The main objectives were to determine the status of the sub-population and to elucidate the ecology and behavior of this social carnivore. This paper describes the decline of the sub-population, the dynamics of pack composition, and patterns of dispersal.
1.
The study provides information on the intra-specific variation in social behaviour found within carnivores in terms of food supply. Jackals were chosen for study because they live in a variety of habitats, in several of which they had already been studied by others.
2.
An area was selected where at least a section of the jackal population obtained 92% of its food from one feeding site of only 10 m2 area (based on analysis of 2,120 faeces). The jackals were observed by day and by night (with infra-red equipment) and many of them could be individually recognised. Other data were gathered by detailed field tracking. Examples of the jackals' behaviour and the interactions both within and between groups are described.
3.
Some of the jackals of this area were organised into two groups (numbering about 20 and 10 individuals respectively); these two groups had a stable composition and occupied neighbouring ranges which, for one of them, could be termed a territory. The limit of this territory was delineated by faeces arranged in piles or middens. Food marking experiments and subsequent faecal analysis confirmed that these middens marked a genuine territorial boundary.
4.
These findings are compared with those of other authors and it is clear that the flexibility of carnivore social systems in general, and that of jackals in particular, is considerable. The limits to the flexibility of social systems differ for various carnivore species. The description of selection pressures which have fashioned inter-specific differences in the possibilities for intra-specific variation within carnivore communities is an important task for the future.
1.
Food and foraging behaviour of the European badger (Meles meles L.) are described for a study area in south-central England, with the aim of understanding the biological function of badgers' spatial organisation. Animals were followed with the aid of radio-location and observed through infra-red night glasses.
2.
The diet consisted largely of one species of earthworm, Lumbricus terrestris.
3.
Worm abundance was measured by formalin-sampling of different vegetation types, and prey appeared to be super-abundant.
4.
Prey availability was restricted; badgers caught worms on the surface at night, where worms could be found in small and temporally highly unstable patches. Factors influencing the existence of these worm-patches are discussed.
5.
A hypothesis is presented which suggests that the physiography of the area determined worm-patch dispersal, and thereby the range size of the badgers, whilst the number of badgers in each range, i.e. the group size, is determined by the quality of the food patches.
6.
It is suggested that one of the selective advantages of a larger group size is the joint territorial defense.
Monogamous pairings have been regarded as the fundamental social unit in all canid species, including those living in packs.
In Ethiopian wolves, however, habitat saturation limits dispersal, which raises the question of whether they avoid inbreeding
and, if so, by what mechanism. In two study areas Ethiopian wolf packs had stable memberships. Each pack comprised two to
eight adult males, one to three adult females, including a clear-cut dominant individual of each sex, together with one to
six yearlings and up to six pups (n = 9 packs). Males remained in their natal packs, apparently throughout their lives. Some females also failed to disperse
while others dispersed in their second or third year and became floaters. Dominant females monopolized breeding, and were
succeeded either by their most dominant daughters (three cases) or by floaters (two cases). In the former case there is potential
for incest; however, 70% of 30 copulations observed were between the dominant female of one pack and a male from an adjoining
pack. In Ethiopian wolves, under conditions where dispersal is constrained and the potential for inbreeding is high, extra-pack
matings (and associated multiple paternity) result in outbreeding. We raise the possibility that extra-pair copulations may
be widespread in canid societies and that the monogamy supposedly fundamental to the family may be more sociological than
genetic.
Spotted hyaenas use a loud call, the whoop. In this study, whoops served three main functions: (1) to display identity; (2) to request support; and (3) to convey information about the location of the caller. An analysis of ontogenetic changes revealed a common functional framework of loud calling for cubs and adults. Cubs primarily whooped to provide information about their location and to request support, while adults mainly whooped to display their identity, males more so than females. Females whooped during agonistic encounters with other female clan members and clashes with neighbouring clans, when locating offspring and when rallying group members to defend communal resources. Whooping in males was mainly used for inter- and intra-sexual display. Self-advertisement (vocal display) was the most common function of whooping at the communal den. Both sexes displayed vocally, but males called at higher rates than females. High-ranking females displayed vocally at a higher rate than subordinates to assert their priority of access to kills in the clan's core range. Breeding females also whooped to deter potentially infanticidal non-clan members from approaching cubs at the communal den. Spotted hyaenas are polygynous, and male vocal display rates are an important component of inter-male competition. Display rates may also influence mate choice by the dominant and more aggressive females. Dominant males exerted more effort when whooping than subordinates by having higher display rates, more often using the energetically more costly type S whoop, and producing more calls per bout. All top ranked males are old, and have probably held long tenure in the clan. If females only mate with dominant males they may select mates on the basis of age, familiarity, display effort or a combination of these factors.
The giant molerat Tachyoryctes macrocephalus is a high-altitude specialist endemic to the Bale Mountains, Ethiopia, and an important prey species for the endangered Ethiopian wolf Canis simensis. We assessed molerat prevalence, habitat preferences and availability to wolves, using direct observation and transect sampling for field signs. Mean densities of molerats ranged from 17/ha to 40/ha, and they were most prevalent in Afroalpine grasslands, particularly along swamp shores in the Web Valley. Wolf densities were greatest in habitats with highest molerat populations. Molerats spent just under an hour a day above ground, and their peak activity periods correlated positively with wolf foraging activity. Molerat distribution may be restricted by thermoregulatory and burrowing requirements: field signs were most abundant where soil depth was greater than 50 cm. Conservation measures aimed at the Ethiopian wolf in the Bale Mountains should take account of the role of the giant molerat.
This paper reviews experimental and field studies on scent marking behaviour. The occurrence and effects of scent marking are considered in particular, and a number of areas for further research are made apparent. Marking behaviour in mammals is often stated to be ‘territorial’ or, more specifically, to play a role in territorial defence. In fact there is a shortage of evidence to support this view; many of the relevant observations are anecdotal or interpreted with preconceived notions of function in mind. While marking is clearly associated with aggressive behaviour in many species and may therefore be related in some way to territorial behaviour, its role in aggression is not understood. Moreover, there is evidence to support a number of other theories of function some of which are unrelated to territory. It seems that, as with any other mode of communication, scent marking has become adapted for use in a variety of contexts. It probably has more than one function in any one species and different functions in different species.
Howls were recorded from seven captive wolves temporarily individually isolated from their pack-mates. Sound spectrograms of these recordings were then digitized and 14 variables were measured and subjected to multivariate statistical analyses. Both principal components analysis and discriminant analysis indicated that individuals could be reliably discriminated primarily on the basis of the fundamental frequency of howls and the variability of frequency within howls. The significance of the presence of vocal signatures in this long distance vocalization is discussed in the context of wolf social organization.
Thesis (Ph. D.)--University of Wyoming, 1978. Includes bibliographical references (leaves [84]-87). Microfilm. s
Thesis (Ph. D.)--University of Oxford, 1994.
BLDSC reference no.: D22601/78. Thesis (doctoral)--University of Oxford, 1977.
Observational study of behavior: sampling methods The use of fecal marking sites by spotted hyaenas and civets
- J Altmann
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Faeces matching in the European badger (Meles meles): a possible role in range exclusion
- P D Stewart
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- C Newman
- C Cheeseman
Stewart, P. D., Macdonald, D. W., Newman, C. & Cheeseman, C. (In prep.). Faeces matching in the European badger (Meles meles): a possible role in range exclusion.
Coyote communication. In Coyotes: biology, behavior and management
- P N Lehner
Lehner, P. N. (1978). Coyote communication. In Coyotes: biology, behavior and management: 127±162. Bekoff, M. (Ed.). New York: Academic Press.
Dispersal and philopatry
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Pusey, A. E. & Packer, C. (1987). Dispersal and philopatry. In Primate societies: 250±266. Smuts, B. B., Cheney, D. L., Seyfarth, R. M., Wrangham, R. W. & Struhsaker, T. T. (Eds).
Pattern of scent marking with urine and feces amongst social communities
- Macdonald D. W.
Macdonald, D. W. (1980). Pattern of scent marking with urine and feces amongst social communities. Proc. R. Soc. Lond. 45: 107±139.
The carnivores: order Carnivora
- D W Macdonald
Macdonald, D. W. (1985). The carnivores: order Carnivora. In Social odours in mammals: 619±722. Brown, R. E. & Macdo-nald, D. W. (Eds).
WILDTRAK. Non-parametric home-range analysis for Mackintosh computers
- I A Todd
Todd, I. A. (1992). WILDTRAK. Non-parametric home-range analysis for Mackintosh computers. U.K.: Department of Zoology, University of Oxford.
Group territories of carnivores: empires and enclaves
- H Kruuk
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Ericaceous forests and heathlands in the Bale Mountains of South Ethiopia Ecology and man's impact. Hamburg: Stiftung Walderhaltung in Afrika Minitab Release 8.21 for DOS
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Scent marking in the Canidae In Play, exploration and territory in mammals
- D G Kleiman
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Faeces matching in the European badger
- Stewart P. D.