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-Plot showing the number of videos of Dromiciops gliroides recorded daily as a function of the coefficient of variation (CV) of temperature estimated for each day during the activity period (dark period of the day). The solid line is the average activity estimated from the model. The dashed lines represent the values of activity estimated for summer (which included mid-and late summer estimates) and autumn (which included early and midautumn estimates).
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The importance of a frugivore’s behavior and movement on seed dispersal patterns, although widely recognized, is sometimes difficult to obtain. This is particularly true for small and nocturnal animals that inhabit structurally complex environments, such as Dromiciops gliroides. We studied different behavioral traits of this species in its natural...
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Context 1
... new-moon nights, individuals were more active than during half-and full-moon nights. On average, during new-moon nights we expected to record almost twice the number of videos recorded during half-moon nights (Table 1; Fig. 3). When temperatures were more homogeneous D. gliroides was more active than during nights with more variable temperatures (Fig. 4). For example, for a night with an average coefficient of variation (and with all other variables at average values) we expected to record about 2.9 videos, but for nights with minimum coefficient of variation, the model predicts 10.8 records of activity (Table 1). Although we did not find evidence of the effect of ripe fruit ...
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... (Table 1; Fig. 3). Seasons seemed to have significant effects on this species' activity levels, with lower activity during mid-and late summer. For instance, under this model we expected to record 0.24 and 0.43 videos per day during mid-and late summer, respectively, and 2.66 and 1.34 during early and midautumn, respectively (see Table 1; Fig. ...
Citations
... Marsupial predators synchronize their activities to periods at which their prey is most active, while preys avoid the times when encounter rates are high (Moss and Croft 1988;Righetti et al. 2000). At freezing days, no or low activity reduces energy loss by thermoregulation (Gillette 1980;Franco et al. 2011), while at times of high energetic needs, activity is extended (Atramentowicz 1982;di Virgilio et al. 2014). Differences in activity pattern among species and populations may represent strategies adopted by individuals to deal with locally limiting factors, thus revealing a level of plasticity in the clade. ...
... Most of the available information relates to the first and third aspects, and information about the second aspect has received limited attention. Another important aspect of activity, the time budgetallocation of time and other resources to different activities (e.g., feeding, browsing, moving)was evaluated only in two studies (McManus 1971;di Virgilio et al. 2014). ...
... Thermal constraints also limit activity of D. gliroides, a small (16-32 g), microbiotheriid marsupial living in temperate rainforests of Chile and Argentina. When nightly air temperatures were relatively constant, D. gliroides remained active for longer periods than during nights with more variable temperatures (Franco et al. 2011;di Virgilio et al. 2014). To survive in this challenging environment, monito del monte exhibits daily torpor and hibernation (multiday torpor, Geiser 1994). ...
... Thus, D. bozinovici feeds on both mistletoes simultaneously ( Figure 3) and deposits T. corymbosus' seeds over D. mutabilis branches while feeding on its fruits. As this marsupial has short gut passage times (about 30 min) and feeding bouts of 16-20 min, it probably defecates seeds during the next feeding bout (di Virgilio et al., 2014;Salazar & Fontúrbel, 2016) via a mechanism similar to that which produces multiple T. corymbosus infections within the same host plant (Fontúrbel et al., 2015). Nothofagus trees with mistletoe hyperparasitism represent 30% of the infected individuals. ...
... Animals must adjust their behavior to optimize their foraging time while minimizing risks (Di Virgilio et al. 2014) and respond to climate changes and food availability, which may lead to seasonal behavioral variation (Stokes et al. 2001;Donati et al. 2016;Pagon et al. 2013). In turn, animal activity is linked with structural characteristics depending on their habitat requirements, such as escape from predation, foraging efficiency, or reproduction demands (Sieving et al. 1996;Rodriguez-Cabal and Branch 2011;Bro-Jørgensen 2008;Connolly and Orrock 2018). ...
... In turn, animal activity is linked with structural characteristics depending on their habitat requirements, such as escape from predation, foraging efficiency, or reproduction demands (Sieving et al. 1996;Rodriguez-Cabal and Branch 2011;Bro-Jørgensen 2008;Connolly and Orrock 2018). For example, small nocturnal mammals perceive moonlight as an indirect cue of predation risk, so they modify their behavior by reducing the use of open space or foraging activity on the brightest nights (Griffin et al. 2005;Stokes et al. 2001;Di Virgilio et al. 2014;Kotler et al. 2010;Orrock et al. 2004). These animals are more oriented by smell and hearing than vision and they are more active below a threshold of moonlight illuminance. ...
... The circadian activity of this small marsupial has received special attention. For example, some authors have evaluated its movement behavior (Franco et al. 2019) and frugivore activity during Tristerix corymbosus fruiting season (Di Virgilio et al. 2014). Others have focused on the variation of activity patterns between native and exotic habitats (Fontúrbel et al. 2014) and along a habitat disturbance gradient (Rodríguez-Gómez and Fontúrbel 2020). ...
Spatial and temporal heterogeneity can affect animal activity patterns under environmental conditions that fluctuate over time and space. The activity timing and habitat structure are essential components of the animals' choices. Here we studied the spatio-temporal activity dynamics of an arboreal marsupial (Dromiciops gliroides) with a key ecological role, endemic to the Andean Patagonian forest. Using camera traps and live traps, we determined temporal variations and the effect of the spatial variables at the micro (habitat structure)- and macro (forest type and geographic location)-scales on the activity patterns of D. gliroides. We built a hierarchical regression model to accommodate variation at both temporal and spatial levels. At a temporal level, we found that D. gliroides was affected by seasonality, increasing their activity toward the end of the summer and the beginning of autumn. At a spatial level, habitat structure was extremely important for this marsupial, particularly shrub cover which positively affected D. gliroides activity. Behavioral adjustments that we documented may be driven by differences in resource availability or predator avoidance. These findings help to understand the mechanisms modulating the activity of D. gliroides, essential for the conservation of this species with an ecological role that allows extended positive consequences to the whole forest community. Our results further support the importance of understory conservation for the survival of this species and warn about the negative consequences of habitat degradation.
... Fruits of several plant species are important in the diet of Dromiciops (Amico et al. 2009(Amico et al. , 2011Vazquez et al. 2021a). Besides, temperature variation influences Dromiciops activity patterns, being these animals more active during nights with constant temperatures (Di Virgilio et al. 2014). ...
The Monitos del monte (genus Dromiciops) are endemic marsupials displaying a key ecological role inside the Patagon-ian temperate forest, a region of hotspot for biodiversity. Here, we predicted the potential distribution of D. gliroides and D. bozinovici and evaluated their conservation issues by quantifying the protected surface of both species. We found that Annual precipitation, Precipitation of Warmest Quarter and Precipitation Seasonality, Max Temperature of Warmest Month and Isothermality were the main environmental determinants in the models. Each species showed particular requirements, suggesting an environmental niche partitioning. On the other hand, we found that only 15% of the total potential distribution area for D. bozinovici and 24% for D. gliroides are currently protected. Although both species are threatened by habitat loss and degradation, the current situation for D. bozinovici is more critical. Overall, our study provides useful information for the management of the most critical areas for Dromiciops conservation.
... Marsupial predators synchronize their activities to periods at which their prey is most active, while preys avoid the times when encounter rates are high (Moss and Croft 1988;Righetti et al. 2000). At freezing days, no or low activity reduces energy loss by thermoregulation (Gillette 1980;Franco et al. 2011), while at times of high energetic needs, activity is extended (Atramentowicz 1982;di Virgilio et al. 2014). Differences in activity pattern among species and populations may represent strategies adopted by individuals to deal with locally limiting factors, thus revealing a level of plasticity in the clade. ...
... Most of the available information relates to the first and third aspects, and information about the second aspect has received limited attention. Another important aspect of activity, the time budgetallocation of time and other resources to different activities (e.g., feeding, browsing, moving)was evaluated only in two studies (McManus 1971;di Virgilio et al. 2014). ...
... Thermal constraints also limit activity of D. gliroides, a small (16-32 g), microbiotheriid marsupial living in temperate rainforests of Chile and Argentina. When nightly air temperatures were relatively constant, D. gliroides remained active for longer periods than during nights with more variable temperatures (Franco et al. 2011;di Virgilio et al. 2014). To survive in this challenging environment, monito del monte exhibits daily torpor and hibernation (multiday torpor, Geiser 1994). ...
New World marsupials have a striking diversity of activity patterns. Until now, knowledge on diel activity was normally granted by means of simple classifications, like diurnal or nocturnal. Although most activity occurs during the night, diurnal and crepuscular activities are not uncommon. New World marsupials tend to be active soon after sunset, using the first half of the night more intensely. A second peak of activity is also observed. Temporal plasticity in the group is evident: activity varies in response to changes in abiotic factors (e.g., temperature, food availability, moonlight) and intra- and interspecific interactions (e.g., predators, competitors). Several studies have focused on the effects of moonlight on suppressing activity of potential preys like marsupials. Results, however, are inconclusive; some species reduce while others increase activity in bright moon nights. The effect of seasonality in food availability and temperature were also highly investigated. Overall, marsupials increase activity in periods of reduced food availability and avoid exposure to cold environments. Future studies should focus on new methodologies which will open new possibilities for investigating activity patterns and for testing hypotheses concerning the response of New World marsupials to anthropogenic changes in the environment.
... They can run vertically through the bark of the Nothofagus at speeds of up to 1 m s À1 and can leap with enormous precision between distant branches up to 1 m apart. 20,22 This is attained by visual and cerebellar adaptations to discriminate distances in absolute darkness, 23,24 and most likely given their Australidelphia condition, they possess trichromacy (color vision in the ultraviolet-infrared spectrum). 25 The recent discovery that the fur of monitos fluoresces pink under UV light exposure supports this idea. ...
... Every peak or ''rewarming'' is a period of euthermia when animals remain in the site, mostly sleeping. 24,112,140 After reproduction in March (end of summer, the graph starts in April), Dromiciops gliroides starts to reduce activity and energy expenditure and accumulate almost twice its body size in fat. 140 Fat accumulation was estimated from body mass fluctuations using quantitative magnetic resonance, which indicated that animals could double their body mass in autumn. ...
With the expansion of human settlements and the environmental changes brought on by human activity and pollutants toxicology and risk assessment of mammal species is becoming increasingly of interest to toxicologists involved in environmental research. This book focuses specifically on environmental risk assessment in marsupial and placental mammals. Marsupial ecotoxicology is poorly understood in scientific research and as such environmental risk assessment in marsupials is an area of rapidly growing interest. This book will be an ideal companion to toxicologists and ecologists interested in risk assessment in the environments of mammals. Particularly those with an interest in the impact introduced by human activity. The book will also be of interest to those working in conservation biology, biological invasion, biocontrol and habitat management.
... The thermograph was calibrated by placing a thermocouple on different surfaces of the mesocosm substrate and confirming that the reading at that point was identical to that generated by the pixel on the thermograph screen. The thermocouple was placed on ice and on glass (Quijano 2008;Franco et al. 2011;Di Virgilio et al. 2014). After reproduction, D. gliroides reduce activity and energy expenditure and accumulate almost twice their body size in fat (Franco et al. 2017). ...
During the past 60 years, mammalian hibernation (i.e., seasonal torpor) has been interpreted as a physiological adaptation for energy economy. However, direct field comparisons of energy expenditure and torpor use in hibernating and active free-ranging animals are scarce. Here, we followed the complete hibernation cycle of a fat-storing hibernator, the marsupial Dromiciops gli-roides, in its natural habitat. Using replicated mesocosms, we experimentally manipulated energy availability and measured torpor use, hibernacula use, and social clustering throughout the entire hibernation season. Also, we measured energy flow using daily food intake, daily energy expenditure (DEE), and basal metabolic rate (BMR) in winter. We hypothesized that when facing chronic caloric restriction (CCR), a hibernator should maximize torpor frequency to compensate for the energetic deficit, compared with individuals fed ad lib. (controls). However, being torpid at low temperatures could increase other burdens (e.g., cost of rewarming, freezing risks). Our results revealed that CCR animals, compared with control animals, did not promote heat conservation strategies (i.e., clustering and hibernacula use). Instead , they gradually increased torpor frequency and reduced DEE and, as a consequence, recovered weight at the end of the season. Also, CCR animals consumed food at a rate of 50.8 kJ d 21 , whereas control animals consumed food at a rate of 98.4 kJ d 21. Similarly, the DEE of CCR animals in winter was 47:3 5 5:64 kJ d 21 , which was significantly lower than control animals (DEE p 88:0 5 5:84 kJ d 21). However, BMR and lean mass of CCR and control animals did not vary significantly, suggesting that animals maintained full metabolic capacities. This study shows that the use of torpor can be modulated depending on energy supply, thus optimizing energy budgeting. This plasticity in the use of het-erothermy as an energy-saving strategy would explain the occurrence of this marsupial in a broad latitudinal and altitudinal range. Overall, this study suggests that hibernation is a powerful strategy to modulate energy expenditure in mammals from temperate regions.
... For example, captive D. gliroides individuals seem to be more active during summer than during other seasons (Aizen, 2003;Kelt & Martínez, 1989), but recently, several authors have studied Dromiciops activity in the field. For instance, found that this species presents a nocturnal activity (from 19:00 h to 07:00 h), with a significant monthly variation related to resource abundance and distribution, closely related to fleshy fruit availability (di Virgilio et al., 2014;Fontúrbel et al., 2017b). ...
... leaves, Hymenophyllum spp. ferns, and lined with many moss species F I G U R E 7 A hypothetical (but realistic) annual budget of energy and activity of a M B = 40 g (lean mass) Dromiciops gliroides, summarized from descriptions of the reproductive cycle (Muñoz-Pedreros et al., 2005), seasonal variations in activity, adiposity, and body mass (Celis-Diez et al., 2012;Franco et al., 2017), and food availability Quijano, 2008;di Virgilio et al., 2014). After reproduction, D. gliroides reduce activity and energy expenditure (dashed line) and accumulate almost twice their body size in fat (Franco et al., 2017). ...
... They can run vertically up the bark of the Nothofagus at speeds of up to 1 m/s and can leap with enormous precision between distant branches up to 1 m far (Balazote-Oliver et al., 2017;Mejías et al., 2021). This is attained by visual and cerebellar adaptations to discriminate distances in absolute darkness(di Virgilio et al., 2014;Gurovich & Ashwell, 2020), and most likely given their Australidelphia trichromate condition (color vision in the ultraviolet-infrared spectrum;Arrese et al., 2002). The recent discovery that Dromiciops fur fluoresces pink with UV light supports this idea (C. ...
The arboreal marsupial monito del monte (genus Dromiciops, with two recognized species) is a paradigmatic mammal. It is the sole living representative of the order Microbiotheria, the ancestor lineage of Australian marsupials. Also, this marsupial is the unique frugivorous mammal in the temperate rainforest, being the main seed disperser of several endemic plants of this ecosystem, thus acting as keystone species. Dromiciops is also one of the few hibernating mammals in South America, spending half of the year in a physiological dormancy where metabolism is reduced to 10% of normal levels. This capacity to reduce energy expenditure in winter contrasts with the enormous energy turnover rate they experience in spring and summer. The unique life history strategies of this living Microbiotheria, characterized by an alternation of life in the slow and fast lanes, putatively represent ancestral traits that permitted these cold‐adapted mammals to survive in this environment. Here, we describe the ecological role of this emblematic marsupial, summarizing the ecophysiology of hibernation and sociality, updated phylogeographic relationships, reproductive cycle, trophic relationships, mutualisms, conservation, and threats. This marsupial shows high densities, despite presenting slow reproductive rates, a paradox explained by the unique characteristics of its three‐dimensional habitat. We finally suggest immediate actions to protect these species that may be threatened in the near future due to habitat destruction and climate change. We present a review summarizing the recent advances on the biology of the enigmatic monito del monte, a relict Gondwanan mammal from southern South America.
... Dromiciops gliroides is an omnivorous species, consuming fruits and insects. Most descriptions of the diet are qualitative and based on fecal analysis and laboratory preference trials Celis-Diez et al., 2012;Cortés et al., 2011;Di Virgilio et al., 2014;Quijano, 2008). This marsupial is considered an ecological architect (Fontúrbel & Jiménez, 2011) because it can regulate the spatial distribution of the mistletoe Tristerix corymbosus (Amico et al., 2017;García et al., 2009). ...
... However, in a study using camera traps to evaluate the fruit removal of the mistletoe T. corymbosus, the authors found that D. gliroides F I G U R E 3 Fleshy fruit species present in the Patagonian temperate forest and dispersed by Dromiciops gliroides, classified according to their life form. The graph shows the total fleshy fruit species (left column) and the preference of D. gliroides (right column) for each type of life form consume generally 3 fruits (1-10 fruits) per plant (Di Virgilio et al., 2014), whereas their feces usually have between 1 and 31 seeds (Amico et al., , 2011(Amico et al., , 2017Vitali et al., 2021). In other studies, seeds of several species, including A. chilensis (1-6 seeds), Azara microphylla (4-27 seeds), B. darwini (3-10 seeds), G. mucronata (55 seeds), R. magellanicum (9-15 seeds), S. patagonicus (1-6 seeds), and Ugni molinae (21-105 seeds), were also detected in D. gliroides feces Celis-Diez et al., 2012;Mora & Soto-Gamboa, 2011;Vitali et al., 2021). ...
Seed dispersal by vertebrate animals is critical for the establishment of fleshy-fruited plant species. In regions with impoverished faunas, such as the Patagonian temperate forest, the arboreal marsupial Dromiciops gliroides plays a key role as a seed disperser. Here, we assessed the ecological role of D. gliroides as a seed disperser and their possible effects on the plant structure of the Patagonian temperate forest. We found that the passage through the digestive tract of D. gliroides increased germination rate in four of the five groups of plants evaluated. Additionally, we found that D. gliroides disperses all the epiphytes, almost a quarter of the vines and parasites, and could disperse about half of the trees and shrubs present in the Patagonian temperate forest. Taken together, our results demonstrate the keystone dispersing role played by D. gliroides within the Patagonian temperate forest and highlight the importance of its conservation for the preservation of this highly endemic flora. K E Y W O R D S Dromiciops gliroides, fleshy fruit, germination, Patagonian temperate forest, seed dispersal
... For example, captive D. gliroides individuals seem to be more active during summer than during other seasons (Aizen, 2003;Kelt & Martínez, 1989), but recently, several authors have studied Dromiciops activity in the field. For instance, found that this species presents a nocturnal activity (from 19:00 h to 07:00 h), with a significant monthly variation related to resource abundance and distribution, closely related to fleshy fruit availability (di Virgilio et al., 2014;Fontúrbel et al., 2017b). ...
... leaves, Hymenophyllum spp. ferns, and lined with many moss species F I G U R E 7 A hypothetical (but realistic) annual budget of energy and activity of a M B = 40 g (lean mass) Dromiciops gliroides, summarized from descriptions of the reproductive cycle (Muñoz-Pedreros et al., 2005), seasonal variations in activity, adiposity, and body mass (Celis-Diez et al., 2012;Franco et al., 2017), and food availability Quijano, 2008;di Virgilio et al., 2014). After reproduction, D. gliroides reduce activity and energy expenditure (dashed line) and accumulate almost twice their body size in fat (Franco et al., 2017). ...
... They can run vertically up the bark of the Nothofagus at speeds of up to 1 m/s and can leap with enormous precision between distant branches up to 1 m far (Balazote-Oliver et al., 2017;Mejías et al., 2021). This is attained by visual and cerebellar adaptations to discriminate distances in absolute darkness(di Virgilio et al., 2014;Gurovich & Ashwell, 2020), and most likely given their Australidelphia trichromate condition (color vision in the ultraviolet-infrared spectrum;Arrese et al., 2002). The recent discovery that Dromiciops fur fluoresces pink with UV light supports this idea (C. ...
The arboreal marsupial Monito del Monte (genus Dromiciops, with two recognized species) is a paradigmatic mammal. It is the sole living representative of the order Microbiotheria, the ancestor lineage of Australian marsupials. Also, this marsupial is the unique frugivorous mammal in the temperate rainforest, being the main seed disperser of several endemic plants of this ecosystem, thus acting as keystone species. Dromiciops is also one of the few hibernating mammals in South America, spending half of the year in a physiological dormancy where metabolism is reduced to 10% of normal levels. This capacity to reduce energy expenditure in winter contrasts with the enormous energy turnover rate they experience in spring and summer. The unique life-history strategies of this living Microbiotheria, characterized by an alternation of life in the slow and fast lanes, putatively represent ancestral traits that permitted these cold-adapted mammals to survive in this environment. Here we describe the ecological role of this emblematic marsupial, summarizing the ecophysiology of hibernation and sociality, actualized phylogeographic relationships, reproductive cycle, trophic relationships, mutualisms, conservation and threats. This marsupial shows high densities, despite presenting slow reproductive rates, a paradox that is explained by the unique characteristics of its three-dimensional habitat. We finally suggest immediate actions to protect these locally abundant but globally threatened species.
