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Population sizes and breeding rhythms of two species of manakins in relation to food supply
... In temperate and tropical systems, seasonal shifts in the availability of fruit leads to many frugivores tracking their fruit resources over space and time e.g., resplendent quetzal Pharomachrus mocinno tracking the abundance of Lauraceous fruits (Wheelwright 1983), temperate tits Paridae and thrushes Turdus spp. (Sorensen 1981), tropical Australian fruit pigeons (Crome 1975;Innis 1989), manakins (Worthington 1982) and the Central African hornbills, Ceratogymna atrata and C. cylindricus (Whitney and Smith 1998). ...
... In addition to changing occurrence patterns, such tracking of food resources can influence life-history, resulting in breeding seasons coinciding with periods of high food abundance and is apparent at a coarse scale for several avian resource specialists, e.g., piñon jays Gymnorhinus cyanocephalus (Ligon 1978), kakapo Strigops habroptilus (Cockrem 2006) and red crossbills Loxia curvirostra complex (Hahn 1998). Similar trends are apparent for some frugivores e.g., the phainopepla Phainopepla nitens (Walsberg 1977;Chu 1999;Crampton 2004), southern temperate zone fruit pigeons (Powlesland et al. 1997), Australian tropical fruit pigeons (Crome 1975;Innis 1989), oilbirds (Snow 1962), resplendent quetzal (Wheelwright 1983;Solorzano, Castillo, Valverde and Avila 2000), manakins (Worthington 1982) and white-crowned fruit pigeons Columba leucocephala (Bancroft, Bowman, and Sawicki 2000). Although these studies provide a link between the abundance of fruit and consumer responses, they cannot identify subtle effects of resource variation on frugivore ecology (e.g., clutch initiation) because they do not consider variation in fruit abundance and associated responses at scales sensitive enough to detect fine-scale responses. ...
... This is a similar spatio-temporal pattern observed in another mistletoe specialist, phainopepla Phainopepla nitens (Walsberg 1977;Chu 1999;Crampton 2004) and exemplifies the expected tight response by dietary specialists to constraints imposed by the spatial and temporal availability of their key resources. The data suggest that painted honeyeaters timed their departure from the study area as a response to the rapid decline in fruit abundance and suggests that breeding is limited by predictable food shortages, as has been suggested for some frugivorous manakins in lowland rainforests (Worthington 1982) and the phainopepla (Chu 1999). The influence of temporal variability in food abundance has been implicated in the timing of breeding for other honeyeaters e.g., silver-crowned friarbirds Philemon argenticeps (Noske and Franklin 1999), noisy friarbirds P. corniculatus (Tokue and Ford 2006) and New Holland honeyeaters (Ford 1980;Paton 1982), as well as other frugivores in a range of systems (Snow 1962;Crome 1975;Wheelwright 1983;Powlesland, Dilks, Flux, and Tisdall 1997;Chu 1999;Bancroft et al. 2000;Crampton 2004). ...
PhD thesis examining frugivore / food resource relationships using the dietary specialist Painted Honeyeater and mistletoe and as a model study system.
... 75% of the 97 avian lekking species are frugivorous; [23]). At the proximate level, the distribution and availability of resources, such as fruit, can influence lek placement, size and density [12,24,25]. Lekking display behaviour is also energetically demanding [26,27], leading to the hypothesis that resource availability should be positively correlated with male survival and recruitment, and therefore with lek stability. ...
... previously for P. filicauda [15], but within the ranges reported for other Pipridae [16,17]. Previous work has shown that leks are located in food-rich areas [12,25] and that resource availability can influence lek size and population density [24]. Therefore, lek placement in environmental hotspots could influence survival of territory holders directly [12] or indirectly if these males use public information to increase foraging efficiency [52]. ...
... In the northern Neotropics, where ENSO effects rainfall patterns, El Niñ o droughts have been shown to induce synchronized flowering and increased seed set that subsequently increases the abundance of frugivorous vertebrates [32,33]. More broadly, a number of empirical studies have highlighted negative effects of fruit scarcity on body condition [61], breeding phenology [24] and population dynamics [32,62]. We found that territorial male P. filicauda had both higher survival and individual body condition following El Niñ o years, associated with presumably greater fruit abundance, and lower condition and survival following La Niñ a years. ...
Lekking is a rare, but iconic mating system where polygynous males aggregate and perform group displays to attract females. Existing theory postulates that demographic and environmental stability are required for lekking to be an evolutionarily viable reproductive strategy. However, we lack empirical tests for the hypotheses that lek stability is facilitated by age-specific variation in demographic rates, and by predictable, abundant resources. To address this knowledge gap, we use multistate models to examine how two demographic elements of lek stability-male survival and recruitment-vary with age, social status and phase of the El Nino Southern Oscillation (ENSO) in a Neotropical frugivorous bird, the wire-tailed manakin (Pipra filicauda). Our results show that demographic and environmental conditions were related to lek stability in the Ecuadorean Amazon. Apparent annual survival probability of territorial males was higher than that of non-territorial floaters, and recruitment probability increased as males progressed in an age-graded queue. Moreover, annual survival of territorial males and body condition of both floaters and territory holders were higher following years with El Nino conditions, associated with reduced rainfall and probably higher fruit production in the northern Neotropics, and lower after years with wet, La Nina conditions that predominated our study. Recruitment probabilities varied annually, independent of ENSO phase, and increased over our study period, but the annual mean number of territorial males per lek declined. Our results provide empirical support for hypothesized demographic and environmental drivers of lek dynamics. This study also suggests that climate-mediated changes in resource availability can affect demography and subsequent lek stability in a relatively buffered, lowland rainforest.
... This is usually thought to be where female densities are highest (Hoglund and Robertson 1990b;Théry 1992;Balmford et al. 1993). However, female home range use is often heterogeneous because the locations of resources vary over the breeding season (Hoglund and Robertson 1990b;Bradbury et al. 1989a;Worthington 1982). Males may therefore do best by settling at sites where females' movements are channelled by environmental features. ...
... Second, female mate choice appears to be based on long-term sampling of males rather than on song performance on the day of a visit (Westcott 1992, Chapter 4). Third, the locations of fruiting events varies both within and between breeding seasons (Worthington 1982;D. Graham, pers. ...
... When females do need to relocate mates, it is unlikely that for males settlement at sites where females spend time, i.e. feeding sites, would provide an adequate solution to the problem of display site selection. The ephemeral nature of fruiting events (Worthington 1982;D. Graham, pers. ...
... A number of studies have estimated arthropod abundances on BCI. Depending on the study, weekly, monthly, seasonal, and annual arthropod abundance has been examined in leaf litter, in the understory, in light gaps and at various levels in the forest canopy [Gradwohl & Greenberg, 1982;Levings & Windsor, 1982;Richards & Windsor, 2007;Smythe, 1974Smythe, , 1982Stunz et al., 2003;Wolda, 1982;Worthington, 1982]. All types and size classes of BCI arthropods show some evidence of seasonal and interannual fluctuations [Smythe, 1974[Smythe, , 1982Wolda, 1982Wolda, , 1992. ...
... We hypothesize that the unusually high rainfall in 2010, particularly in December, largely eliminated the arthropod peak expected in December [Oppenheimer, 1982;Smythe, 1982;Worthington, 1982]. With few arthropods available, it is probable that many capuchins could not find sufficient dietary protein to survive. ...
... The December arthropod peak is also hypothesized to be important to other BCI vertebrates. Worthington [1982], for example, speculated that the December arthropod peak might cue breeding activities in BCI manikins. If edible arthropods were in unusually short supply in December/January on BCI and there were no other viable protein sources, we predict many capuchins would rapidly experience negative nitrogen balance, with the ensuing cascade of debilitating metabolic consequences predicted for insufficient dietary protein [Wardlaw & Insell, 1996]. ...
... Unlike aggregated flowering which is likely to decrease pollination success through stigma blocking and hybridization (Stiles 1975), aggregated fruiting could be beneficial to the plants by increasing the probability that seeds are dispersed away from conspecifics, potentially increasing seedling survival (Howe & Primack 1975, Janzen 1970, Ross & Harper 1972, Schupp 1993, Wheelwright & Orians 1982. Aggregated fruiting would not provide a constant food source to animal vectors, but the abundance of frugivores has been shown to vary temporally in many tropical habitats, presumably reflecting movements in response to variation in fruit availability (Levey 1988, Loiselle & Blake 1991, Van Schaik et al. 1993, Wheelwright & Orians 1982, Worthington 1982. ...
... The Psychotria were temporally aggregated in their fruiting phenologies. Fruit production was concentrated in the late wet season, a period of high fruit availability, especially among understorey fleshy-fruited plants (Foster 1982, Worthington 1982. Such a pattern suggests a high potential for both intra-and extrageneric competition for dispersers. ...
... Seasonal changes in the spatial behaviour in these year-round residents suggest that their ability to disperse seeds is highest during the Psychotria fruiting season. During the breeding season (February to July), manakins are sedentary and gather in leks (Foster 1977, Krijger et al. 1997, Worthington 1982 where seeds are often dropped under single display perches to the point of attracting seed predators (Krijger et al. 1997, Stiles et al. 1989. From August to December, adult and first-year individuals spend more time foraging and move longer distances to find fruit (Worthington 1982). ...
Plants potentially compete for seed dispersal. Selection may favour temporally segregated fruiting phenologies to minimize this competition and also to maintain resident populations of dispersal agents. Alternatively, selection may favour temporally aggregated fruiting phenologies when the effectiveness of seed dispersal agents varies seasonally or when large, synchronous fruit displays enhance dispersal. These evolutionary scenarios assume that plants share seed dispersal agents. This assumption and temporal overlap in fruiting phenologies were evaluated for the Miconia and Psychotria of central Panama. These two genera accounted for 18 and 27%, respectively, of 1096 fleshy fruits found in regurgitation or faecal samples taken from 2054 birds of 103 species netted in the forest under- storey. Two species of manakins accounted for 62% (123/200) of all Miconia fruit taken. Three species of manakins and three species of migratory thrushes accounted for 97% (282/292) of all Psychotria fruits taken. There is a high potential for intrageneric competition for seed dispersal for both plant genera. Null model analyses showed that the fruiting phenologies of Miconia (14 species) are segreg- ated in time, while fruiting of Psychotria (21 species) is highly aggregated. The Miconia were found in up to 24% of the diet samples for the two manakin species, suggesting that Miconia may be a critical resource for both species. The Psychotria fruited when the diversity of understorey fruits was greatest, suggesting a high potential for both intra- and extrageneric competition. The abundance and nomad- ism of the six bird species that consumed most Psychotria fruit peaked when the Psychotria fruited, supporting the enhancement hypothesis.
... -At La Selva, fruiting roughly mirrors rainfall. In more seasonal, drier forests, peak fruiting occurs in the late-dry/early-wet season (Janzen 1967, Beals 1970, Smythe 1970, Croat 1975, Crome 1975, Foster 1982a, Worthington 1982. However, for La Selva trees Frankie et al. (1 974: 908) found "little reason to suspect that . . . ...
... Molting and breeding vs. fruit abundance.-The breeding season of tropical fruit-eating birds shows considerable yearly variation (Skutch 1950, Snow and Snow 1964, Snow 1976 but usually corresponds to a time of high or increasing fruit availability (Snow 1962a, b, Crome 1975, Worthington 1982, Wheelwright 1983, Murray 1986. Molt also occurs during a period of fruit abundance (Snow and Snow 1964, Fogden 1972, Snow 1976, Worthington 1982. ...
... breeding season of tropical fruit-eating birds shows considerable yearly variation (Skutch 1950, Snow and Snow 1964, Snow 1976 but usually corresponds to a time of high or increasing fruit availability (Snow 1962a, b, Crome 1975, Worthington 1982, Wheelwright 1983, Murray 1986. Molt also occurs during a period of fruit abundance (Snow and Snow 1964, Fogden 1972, Snow 1976, Worthington 1982. Indeed, the molting season at La Selva generally corresponded to the period of high fruit abundance for the two most common heavy frugivores. ...
Understory fruit and fruit-eating birds were censused monthly for a year in gaps, intact forest, and second-growth sites of a lowland Costa Rican rain forest. Both fruits and birds displayed significant seasonal variation. Peak fruit abundance corresponded with peak fruit-eating bird abundance. Fruits were most abundant in the mid-to-late rainy season (August-January). Crop sizes were larger on second-growth plants than on either gap or intact forest plants. Also, fruit was much more common in second growth than in gaps and more common in gaps than in intact forest. Fruit-eating birds followed the same general patterns of spatial and temporal variation. They were significantly most abundant in second growth, significantly least abundant in intact forest, and most common from October to January. A large increase in the frugivore population in October was due to an influx of temperate and altitudinal migrants. In addition, populations of some resident frugivore species increased concurrently, suggesting altitudinal migration in some of these species as well. The two most common understory frugivores molted during the period of fruit high and bred during the period of fruit low. I suggest that insect abundance may be more important than fruit abundance in determining breeding cycles of these birds. Given the extent of spatial and temporal variation in fruit and frugivore abundance, and the apparent tracking of fruit resources by birds, large areas of diverse habitats are probably necessary for the long-term maintenance of frugivore populations.
... Associations between vegetation structure and avian diversity (MacArthur and MacArthur, 1961;Karr and Roth, 1971) have long been attributed to 1. Frugivory Frugivore densities and movements are often closely correlated with local fruit abundance (Worthington, 1982;Levey, 1988;Blake and Loiselle, 1991;Blake, 1989, 1991;Fleming, this volume). Seasonal changes in fruit availability stimulate various responses in birds. ...
... Seasonal changes in fruit availability stimulate various responses in birds. In time of 9. Regulation olVertebratl' Populations 247 fruit shortage, the frugivorous red-capped manakin (PiPra mentalis) stops breeding, spends more time foraging, and eats more insects (Worthington, 1982). This manakin also moves among forest types to track fruit abundance (Martin and Karr, 1986;Levey, 1988). ...
... The timing of avian reproduction generally coincides with seasonal peaks in food supply (Lack 1968, Daan et al. 1988. Thus, most studies of frugivorous birds in the Neotropics or Australia have concluded that breeding activity is associated with periods of fruit abundance (Snow and Snow 1964, Frith et al. 1976, Worthington 1982; but see Herrera 1998). Variation in the number or density of breeding birds among sites or years reflects general patterns of fruit availability (Crome 1975a, Wiley and, and many frugivores exhibit seasonal movements in response to fruit availability (Crome 1975b, Wheelwright 1983, Innis 1989, Powell and Bjork 1995. ...
... The first prebasic molt in most pigeons occurs 50 to 100 days postfledging (Skutch and Gardner 1991); thus, adults may terminate nesting early enough to allow juveniles to exploit abundant energy-rich fruits to facilitate molt well before migration. In other species, molt occurs during periods of fruit abundance (Snow and Snow 1964, Fogden 1972, Worthington 1982, Poulin et al. 1992. Second, we suspect that the palatability of Metopium fruit may decrease in the fall. ...
White-crowned Pigeons (Columba leucocephala) varied their timing of breeding and nesting intensity in response to variation in production of the four most important fruit species in their breeding-season diet in the upper Florida Keys. From 1988 through 1990, we monitored fruit production year-round in five habitats in which pigeons foraged and monitored all pigeon nests along two transects on Middle Butternut Key. Annually, pigeon breeding was positively correlated with summer rains and with the peak in overall fruit production. However, within the breeding season, only the availability of Metopium toxiferum was positively correlated with rainfall and the number of new clutches initiated. Both the timing and magnitude of breeding varied annually. In 1988, when Metopium was more available, more pigeons nested, the nesting season started earlier and lasted longer, and a large peak in nesting occurred when Metopium fruit ripened. During 1989 and 1990, when the relative availability of Metopium was lower, fewer pigeons nested, the nesting season was shorter, and the seasonal peak in nesting associated with Metopium fruit was reduced or absent. Nesting patterns did not appear to vary with changes in the relative availability of other fruits. White-crowned Pigeons appear to prefer Metopium fruits to other species. Because pigeons do not supplement nestling diets with arthropods, but augment their diets with protein-rich crop milk, they may depend on lipid-rich fruits such as Metopium to provide the energy for breeding and crop-milk production. Metopium fruit production may be influenced by rainfall and climatic conditions, both of which may vary spatially within the range of White-crowned Pigeons in Florida. Evidence that pigeons shift foraging sites when Metopium availability varies emphasizes the need to preserve large tracts of seasonal deciduous forest in the Keys and to protect Metopium trees in suburban areas where they are removed because they cause contact dermatitis in humans.
... Unfortunately, most species in tropical forests are rare (Terborgh et al. 1990, Thiollay 1999), making it difficult to obtain data sufficient to document those patterns and processes. In contrast to most other members of tropical bird communities, manakins (Pipridae) typically are common to abundant in the understory of tropical forests (Karr, Robinson et al. 1990) and, as a consequence, are excellent candidates for studies on various aspects of population dynamics (Worthington 1982, Théry 1992, Graham 1996. Surprisingly, although the breeding biology and behavior of many species of manakins are relatively well known (e.g . ...
... Skutch 1967, Hilty and Brown 1986, Stiles and Skutch 1989, most previous studies that focused on aspects of population dynamics of manakins (e.g. Worthington 1982, Théry 1992, Graham 1996 have been relatively short (Ͻ5 years). Many species of manakins, including all species studied here, are heavily dependent on fruit (Levey 1988, Marini 1992, Rosselli 1994. ...
We used capture and recapture data (1985 to 1994) to examine seasonal variation in habitat use, movements within and among habitats, and survival rates of manakins (Manacus candei, Corapipo altera, Pipra mentalis, P. pipra) in northeastern Costa Rica. Manakins were captured in young and old second-growth woodlands in the lowlands and in old-growth forest at approximately 50, 500, and 1,000 m. Manakin species differed in their use of habitats, with old-growth forest species showing large and predictable seasonal variation in capture rates. Corapipo capture rates in lowland (nonbreeding) habitats were greater during the wet season than during the dry season and were greater in old-growth forest than in second growth. Capture rates at 500 m were higher in the dry season. Pipra mentalis capture rates were high in second growth and old growth. Capture rates were higher in the wet season and were correlated with capture rates of Corapipo, indicating that at least some individual P. mentalis migrate along the elevational gradient. P. pipra capture rates were highest at 1,000 m; few individuals descended to lowlands in the wet season. Manacus capture rates were highest in young second growth and did not vary between wet and dry seasons. Use of second-growth habitats by species typically associated with old-growth forests illustrates the value of maintaining a mosaic of habitats to accommodate seasonal changes in use of habitats. Contrary to expectations based on lek mating systems, there was little evidence that movements within habitats (i.e. recapture distances) varied between sexes. Yet, recapture percentages were higher in all species for adult females than males. Adult survival rates were ∼0.75 for Manacus in young second growth, 0.62 for Corapipo in old-growth forest at 50 m and 0.66 at 500 m, and 0.70 for Pipra mentalis in lowland old-growth forest. Results support the suggestion that geographic variation in survival rates may be common in the tropics and illustrate the need for examining survival rates separately by age and sex.
... The seven study species discussed here differ in at least two major life-history attributes: habitat type and social system (Table 1). Four species inhabit mostly forested habitats: Spotted Antbird (Hylophylax n. naevioides; Willis 1972, Hau et al. 1998, Bicolored Antbird (Gymnopithys leucaspis bicolor; Willis 1967), Song Wren (Cyphorhinus phaeocephalus; Edwards 2000, Robinson andRobinson 2001), and Red-capped Manakin (Pipra mentalis; Worthington 1982). The remaining species, termed ''edge'' or ''open habitat'' species here, occupy second growth (Golden-collared Manakin, Manacus vitellinus, Worthington 1982) or open woodland (Blue-gray Tanager, Thraupis episcopus, Brawn et al. 1996; Claycolored Robin, Turdus grayii, Morton 1971, Stutchbury and Morton 1995, 2001. ...
... Four species inhabit mostly forested habitats: Spotted Antbird (Hylophylax n. naevioides; Willis 1972, Hau et al. 1998, Bicolored Antbird (Gymnopithys leucaspis bicolor; Willis 1967), Song Wren (Cyphorhinus phaeocephalus; Edwards 2000, Robinson andRobinson 2001), and Red-capped Manakin (Pipra mentalis; Worthington 1982). The remaining species, termed ''edge'' or ''open habitat'' species here, occupy second growth (Golden-collared Manakin, Manacus vitellinus, Worthington 1982) or open woodland (Blue-gray Tanager, Thraupis episcopus, Brawn et al. 1996; Claycolored Robin, Turdus grayii, Morton 1971, Stutchbury and Morton 1995, 2001. Spotted Antbirds and Bicolored Antbirds are socially monogamous. ...
We investigated gonad sizes, nesting patterns, and plasma hormone concentrations of seven Neotropical passerine species in a lowland tropical rainforest (Panama) at 9°N latitude over at least one annual cycle. All species had entirely regressed gonads for several months of the year (October to January), coinciding with the end of heavy rainfall. Gonadal recrudescence started in the dry season between January and March. Nesting began earlier (March) for open-habitat species than for forest-interior species (April), and lasted until August or December, respectively. Species differed widely in maximal relative testes sizes and reproductive hormone concentrations, but both measures were lower than in most temperate-zone species. Although we cannot provide a phylogenetically controlled comparison, polygynous and group-living species appeared to have larger testes than monogamous species, possibly indicating sperm competition. Testosterone concentrations were highest in polygynous species, intermediate in socially monogamous species, and lowest in a group-living species, indicating that testosterone is more influenced by social systems than by gonad cycles. Tropical birds may generally maintain low testosterone concentrations and relatively small gonads to decrease overall energy expenditure compared to temperate-zone relatives.
Estacionalidad Reproductiva de Siete Especies Passeriformes Neotropicales
Resumen. Investigamos los tamaños de las gónadas, los patrones de nidificación y las concentraciones hormonales plasmáticas de siete especies de aves paserinas Neotropicales en una selva lluviosa tropical de tierras bajas en Panamá (9°N) durante por lo menos un ciclo anual. Todas las especies tenían gónadas enteramente retraídas por varios meses del año (octubre a enero), coincidiendo con el fin del periodo de precipitación lluviosa pesada. El crecimiento gonadal comenzó en la estación seca, entre enero y marzo. La nidificación comenzó primero en las especies de hábitat abierto (marzo) que en las especies de interior de bosque (abril) y duró hasta agosto y diciembre, respectivamente. Las especies difirieron extensamente en los tamaños relativos máximos de las gónadas y en las concentraciones de la hormona reproductiva, aunque ambas medidas fueron menores que para la mayoría de las especies de la zona templada. Aunque no podemos proveer una comparación controlada por filogenia, las especies poliginias y las especies que viven en grupo tenían testículos más grandes que las especies monógamas, lo que posiblemente podría estar indicando competencia espermática. Las concentraciones de testosterona fueron mayores en las especies poliginias, intermedias en las socialmente monógamas, y menores en las especies que viven en grupo, indicando que la testosterona estaría más influenciada por el sistema social que por los ciclos de las gónadas. Las aves tropicales podrían generalmente mantener niveles bajos de testosterona y tamaños relativamente pequeños de gónadas con el fin de disminuir los gastos energéticos totales en comparación a las especies emparentadas de las zonas templadas.
... Temperate frugivory is a strongly seasonal phenomenon among migrant birds (Thompson and Willson, 1978;Stiles, 1980;Herrera, 1982;Jordano, 1985;Wheelwright, 1986Wheelwright, , 1988Willson, 1986;Snow and Snow, 1988;Noma and Yumoto, 1997;Parrish, 1997) and mammal species, such as carnivores (Debussche and Isenmann, 1989) or warmtemperate pteropodid bats (Funakoshi et al., 1993) which show marked seasonal shifts in diet composition. Tropical frugivores usually exploit fruit food during the whole year, but important seasonal dietary shifts also take place (Snow, 1962a,b,c;Decoux, 1976;Hilty, 1977;Worthington, 1982;Terborgh, 1983;Leighton and Leighton, 1984;Sourd and Gautier-Hion, 1986;Fleming, 1988;Erard et al., 1989;Rogers et al., 1990;Williamson et al., 1990;Conklin-Brittain et al., 1998;Wrangham et al., 1998). ...
... The breeding seasons of certain tropical frugivorous birds (e.g. Snow, 1962a,b;Worthington, 1982), bats (Marshall, 1983;Fleming, 1988) and primates (e.g. Terborgh, 1983) all match local maxima of ripe fruit availability. ...
... But, in our study area most of the trees fruit in pre-monsoon months (March to June) when there are sporadic rains. A similar pattern has also been noted in other studies (Smythe 1970;Croat 1975;Crome 1975;Worthington 1982). Optimum soil moisture levels in the monsoon and post-monsoon months (July to October) seem to be conducive for seed germination, hence this pattern (Singh and Kushwaha 2006). ...
... For fruiting trees too, the synchronization of fruiting peak with higher frugivore density is beneficial for effective dispersal of large quantity of seeds. Different studies have indicated breeding synchronization during the fruiting peak in frugivorous birds (Worthington 1982;Bell 1982;Wheelwright 1983). In our studied system most of the frugivore birds breed between March and June which coincides with high fruiting peaks and also largest amount of tree species fruiting. ...
Frugivores provide a critical ecosystem service by dispersing seeds and therefore play a major role in the survival and maintenance of trees in tropical forests. Avian frugivores constitute one of the major guilds in tropical forests whose activities are significantly governed by the availability of fruits across space and time. In our current study we examined the effects of the spatial and temporal pattern of food availability on avian frugivores and various avian frugivore functional groups in particular. We found a differential effect of fruit density and number of tree species in fruiting on different functional groups of avian frugivores along both spatial and temporal scales. Total frugivore density was best explained by ‘number of tree species in fruiting’ at both special and temporal scale. The variation in large frugivore density was best explained both by ‘fruit density’ and ‘fruit density’ and ‘number of tree species in fruiting’ together. This pattern was observed at a spatial scale but not along temporal scale. Along temporal scale large frugivore density was best explained only by ‘number of tree species in fruiting’. The medium sized frugivore density was not significantly explained by either ‘fruit density’ or ‘number of tree species in fruiting’. The medium sized frugivores are dependent both on insects and fruits and variation in insect density may determine spatial and temporal variation in medium sized frugivore density. The mixed diet frugivore group with a smaller gape width is limited by the variety of fruit they consume and thus their population was significantly controlled by the number of fleshy fruited tree species in fruiting along spatial scale. We observed breeding synchronization during the time of fruiting peak and we suggest that this could be a strategy for effective seed dispersal. Our study indicated very strong dependability of the large frugivore (dependent only on fruit) population on fruit availability unlike the mixed diet frugivore guild (fruit as secondary diet).
... Temperate frugivory is a strongly seasonal phenomenon among migrant birds (Thompson and Willson, 1978;Stiles, 1980;Herrera, 1982;Jordano, 1985;Wheelwright, 1986Wheelwright, , 1988Willson, 1986;Snow and Snow, 1988;Noma and Yumoto, 1997;Parrish, 1997) and mammal species, such as carnivores (Debussche and Isenmann, 1989) or warmtemperate pteropodid bats (Funakoshi et al., 1993) which show marked seasonal shifts in diet composition. Tropical frugivores usually exploit fruit food during the whole year, but important seasonal dietary shifts also take place (Snow, 1962a,b,c;Decoux, 1976;Hilty, 1977;Worthington, 1982;Terborgh, 1983;Leighton and Leighton, 1984;Sourd and Gautier-Hion, 1986;Fleming, 1988;Erard et al., 1989;Rogers et al., 1990;Williamson et al., 1990;Conklin-Brittain et al., 1998;Wrangham et al., 1998). ...
... The breeding seasons of certain tropical frugivorous birds (e.g. Snow, 1962a,b;Worthington, 1982), bats (Marshall, 1983;Fleming, 1988) and primates (e.g. Terborgh, 1983) all match local maxima of ripe fruit availability. ...
This book (11 chapters) presents an overview of seed ecophysiology and its role in shaping plant communities. Updated information on frugivory, seed dispersal, seed predation, light-mediated germination responses, chemical regulation of germination, and seed dormancy is provided. New chapter contributions include an overview of seed development, anatomy and morphology, the chemical ecology of seed persistence, implications of climate change on the regeneration by seeds, and the functional role of seed banks in agricultural and natural ecosystems. This book serves as a highly comprehensive review resource for new students of seed ecology and plant community regeneration, as well as an update for the more seasoned and experienced scientist.
... Manakins (Pipridae) are small frugivorous passerines abundant in the understory of primary and secondary neotropical forests (Blake & Loiselle 2002, Loiselle et al. 2007. Manakins have broad diets, eating whole a great variety of small fruits, thus potentially exerting important role as seed dispersers (Worthington 1982, Blake & Loiselle 2002, Snow 2004. ...
... Snow (1962) recorded 105 species of fruits consumed by M. manacus in Trinidad Island. Worthington (1982) recorded at least 62 species of plants whose fruits were fed by Goldencollared Manakin Manacus vitellinus (Gould, 1843) and Red-capped Manakin Pipra mentalis (P.L. Sclater, 1857) in Barro Colorado Island. Loiselle et al. (2007) Manacus manacus and other manakins have a wide gape in relation to their body size, which allows them to swallow whole fruits that cannot be swallowed by larger birds such as some tanagers (Snow 1962). ...
Manakins (Pipridae) are one of the most abundant fruit-eaters and seed dispersers in the understory of neotropical forests. We describe the fruit diet of the White-beaded Manakin (Manacus manacus) based on a two-year study of its foraging behavior on fruiting plants, collecting seeds from feces and regurgitations of trapped individuals, and from lekking males’ courts in restinga forests at the southern coast of the state of São Paulo, Brazil. Manacus manacus consumed 58 species of fruits from 30 different plant families. Fruits were taken at 3.5 ± 1.9 m height and 1.5 ± 1.6 m below the forest canopy using mainly sally-strike and glean manoeuvres. Most of the fruits were berries ranging from 3.1 to 17 mm in diameter and containing from 1 to 86 seeds. Fruits up to 12 mm in diameter were swallowed whole. Ripe and unripe fruits were equally consumed. Our results corroborate with the great variety of small fruits consumed by manakin species, and indicate that M. manacus is an important seed disperser, potentially contributing to recruitment of plants in restinga
... Astor (1997) also found a decrease in lek activity of M. manacus between February and May in southeastern Brazil (22 • S, 42 • W). In Trinidad (10 • N, 62 • W) and Panama (09 • N, 79 • W), the lek activity of M. manacus, the Golden-collared Manakin (Manacus vitellinus) and the Red-capped Manakin (Pipra mentalis) decreased markedly between July and December (Chapman 1935;Snow 1962;Worthington 1982), showing an inverted pattern of lek activity compared with our data from the subtropical region. In our study, significant correlations between lek attendance of resident males and day lengths in subtropical and tropical regions strengthen the idea that day length is one of the environmental factors (examples of other environmental factors: climate and availability of food resources) that mediates differences in lek attendance of M. manacus (Snow 1962). ...
... In Trinidad, Snow (1962) argued that females frequently visit males in the breeding season, which may last up to 5 months during any year and varies according to environmental factors (such as rainfall) that are important in affecting availability of food resources (arthropods and fruits) for manakins. In Panama, Worthington (1982) detected the beginning of breeding of M. vitellinus and P. mentalis when the fruit supply increased. In general, the first heavy rains marked the beginning of the species' breeding season in tropical as well as in subtropical regions (Snow 1962;CC and MAP, personal observations). ...
Descriptions of lek-breeding in White-bearded Manakins (Manacus manacus) first
appeared 55 years ago from studies conducted in tropical Trinidad. No published
studies on lek activity, however, exist from subtropical areas of the Neotropics.
Herein, annual lek phenology of M. manacus in a subtropical region was analysed
and compared with studies conducted in Trinidad. Day-long observations
were conducted in nine male territories from three leks. Permanence of lekking
males in their territories was positively correlated with day length. When males are
more active in the subtropical region, males from Trinidad are less active and vice
versa. Additional new information about this manakin’s lek activity was disclosed:
residents stayed in their courts for up to 7% of the day length, the frequency and
duration of display bouts of residents varied throughout the year whereas those of
juveniles did not, and females made more visits to courts of residents who displayed
for longer bouts
... Our second goal was to identify the proximate and ultimate causes that dictate the timing of the breeding season at this site. The generally accepted paradigm is that the ultimate cause of seasonal breeding is food availability (Worthington 1982;Wunderle 1982;Young 1994;Zandt et al. 1990;Auer 2007, Cox et al 2013Ewald and Rohwer 1982;Fogden 1972;Grant and Boag 1980). Birds selectively breed at the time of year when food is most abundant and reproduction is most likely to be successful. ...
The timing of reproduction is a fundamental aspect of life history, yet the breeding seasons of most birds of the world, i.e., those in the tropics, remain poorly understood. Here, we use more than 3000 mist-netting records and 300,000 citizen scientist observations collected over 6 years to characterize the nesting, incubation, fledging, and juvenile stages of the breeding season on Singapore Island in Southeast Asia’s equatorial rainforest zone. The breeding season was compared with climate variables and food availability to identify possible proximate and ultimate causes. Breeding was seasonal and began just after the rainiest months of the year, when insect abundance was highest and when masting events were most likely to occur. While true photoperiod varied little throughout the year, overcast weather in November–December and sunnier weather in February–March caused average daily sunshine to increase by several hours at the onset of the breeding season in all 6 years. Our data suggest that subjective daily sunshine hours, which correlate with photoperiod at higher latitudes but not in the tropics, may be the actual proximate trigger of breeding activity in most of the world’s birds.
... Los saltarines forman un grupo interesante para realizar estudios de ecología, comportamiento y evolución por varias razones. Juegan un rol muy importante en la dinámica del bosque ya que son agentes primarios para la dispersión 1 de muchas plantas (Worthington, 1982;Loiselle y Blake, 1999;Blendinger et al., 2008a). Sus sistemas de reproducción mediante el uso de leks proveen muchas oportunidades para formular preguntas sobre comportamiento, tales como la selección de pareja por parte de las hembras, interacciones entre los machos y redes sociales. ...
... Los saltarines forman un grupo interesante para realizar estudios de ecología, comportamiento y evolución por varias razones. Juegan un rol muy importante en la dinámica del bosque ya que son agentes primarios para la dispersión 1 de muchas plantas (Worthington, 1982;Loiselle y Blake, 1999;Blendinger et al., 2008a). Sus sistemas de reproducción mediante el uso de leks proveen muchas oportunidades para formular preguntas sobre comportamiento, tales como la selección de pareja por parte de las hembras, interacciones entre los machos y redes sociales. ...
... The evaluation of the changes in patterns of bird abundance is important for our understanding of factors that could affect population dynamics (survival and mortality) and animal communities (changes in species composition) (Holt, 1993;Yodzis, 1993;Brown, 1995). In bird communities, species often adjust the timing of molting, migration and reproduction to fluctuations in food resourses, which in turn respond to predictable, seasonal climatic changes (Stiles, 1985;Loiselle & Blake, 1991;Worthington, 1996). Unpredictable climatic anomalies such as El Niño Southern Oscillation (hereafter El Niño) and presumably La Niña phenomenon, have a strong impact on survivorship and reproduction in many bird populations, and consequently affect the community structure (Grant & Grant, 1983;Stiles, 1992;Jaksic & Laso, 1999). ...
El Niño and La Niña climatic oscillations have dramatic effects on population dynamics and community structure of different animals. For marine birds, El Niño phenomenon drastically increases their mortality and reduces their reproductive success. In terrestrial ecosystems, the lack of long-term longitudinal data limits our understanding of the impact of El Niño and La Niña on bird populations and communities. We analyzed changes in abundance of frugivorous (large, medium, and small) and nectarivorous birds on three tropical forest types (lowland, premontane and montane) during El Niño, La Niña and neutral years using data from 16 Christmas’ Bird Counts in Costa Rica. Abundance of large and medium size frugivores increased during La Niña events, and the abundance of nectarivores during El Niño in the lowland forest, but neither of these events affected the abundance of small frugivores. In the montane forest, abundance of all four bird groups increased during El Niño, but decreased during La Niña events. Abundance of large, and small frugivores increased in the premontane forest during La Niña events, but other bird groups were not affected by La Niña. The abundance of small frugivores also increased during El Niño. We hypothesize that changes in abundance of frugivores and nectarivores during La Niña and El Niño events is probably correlated with fluctuations in food resources as it has been reported for other terrestrial tropical ecosystems.
... Em geral, as aves frugívoras exploram uma variedade de espécies de frutos, sem especializarem-se em nenhuma espécie ou família em particular. Wheelwright et al. (1984), por exemplo, registraram 95 espécies de frutos na dieta de Aulacorhynchus prasinus (Ramphastidae), enquanto Worthington (1982Worthington ( , 1983 observou Pipra mentalis (Pipridae) se alimentar de mais de 140 espécies na ilha de Barro Colorado no Panamá. Na Mata Atlântica, tucanos e araçaris consomem pelo menos 48 espécies de frutos (Galetti et al. 2000). ...
... White-crowned Manakins inhabit the understory. They are mainly frugivorous (Worthington 1982, Tori 2008), but they also consume some insects (Fair et al. 2013, WPT pers. observ.). ...
Animal patterns of space use have fundamental consequences for ecological processes such as animalmediated seed dispersal. This study examines the use of space of an understory frugivore: the White-crowned Manakin (Dixiphia pipra) during the non-breeding season at Tiputini Biodiversity Station in Ecuador. We radio-tracked seven individuals of different sexes and ages. We found that White-crowned Manakins have relatively small home ranges varying from 1.19 to 5.73 ha. The home ranges of male juveniles (2.25 ± 0.62 SE) were larger than that of the adult males (1.20 ± 0.01 SE), but smaller than those of females (4.27 ± 0.77 SE). Females and second-year males were found to perform more long distance flights outside their core home range than hatch-year or adult males. These movement differences suggest that they disperse seeds longer distances and more evenly across their home range. Adult and hatch-year males appear to perform more short distance seed dispersal events. We argue that these contributions are complementary, and that White-crowned Manakins are key dispersal agents that have a significantly influence in the structure and composition of understory plant communities in the Amazon rainforest.
... Likewise, manakins (~Wanacus ~~itrllinus) were record-Determination of the factors governing fruit pref-ed eating 39 of the 42 species present on Orchid Island erence in birds is of critical importance in understand-in Gatun Lake, Panama (Worthington 1982). Such aping the coevolution of fruiting plants and their dispers-parent lack of choice or clear bases for choice may be ers. ...
The influence of distance between fruiting plants on choice patterns of four species of tanagers and two species of manakins was experimentally tested in a lowland rain forest in Costa Rica. Paired clusters of two fruit species (Miconia affinis and Urera caracasana) were presented on each of two perches separated by selected distances ranging from 0.3 to 6.4. When the two perches were closest together, all the birds ate the preferred berries, M. affinis, on both perches before eating the less preferred U. caracasana. At the extreme perch separation distance, all but one of the birds ate both species of fruits on the first perch before flying to the second perch. The distance at which each bird switched between the two feeding sequences was correlated with the strength of their preference for one species of fruit over another. Manakins switched at greater separation distances than did tanagers. Since manakins take most of their fruit on the wing, the difference in switch distance is likely related to their flight pattern, but no consistent correlation with simple morphological characteristics (wing-loading or aspect ratio) was found. The results suggest that, in the field, less preferred items may often be taken when more preferred fruits are spaced even moderately far apart. The sequence of feeding and, by implication, diet breadth appears to be a consequence of the abundance and spacing of available foods; hence, degree of generalization is a dynamic feature of a bird's foraging pattern. This result supports the prediction that travelling time is an important determinant of prey and patch choice.
... Finalmente, alguns autores utilizam escalas mistas (e.g., Ortiz 1990, Borchert 1980. Especificamente para a quantificação dos eventos fenológicos reprodutivos (floração e frutificação) pode-se, ainda, adotar uma escala de mensuração quantitativa, por exemplo, quando são contadas todas as flores ou frutos de um indivíduo ou ramo (Araújo et al. 1994, Worthington 1996, Pombal & Morellato 2000. ...
... Em geral, as aves frugívoras exploram uma variedade de espécies de frutos, sem especializarem-se em nenhuma espécie ou família em particular. Wheelwright et al. (1984), por exemplo, registraram 95 espécies de frutos na dieta de Aulacorhynchus prasinus (Ramphastidae), enquanto Worthington (1982Worthington ( , 1983, observou Pipra mentalis (Pipridae) se alimentar de mais de 140 espécies na ilha de Barro Colorado no Panamá. Na Mata Atlântica, tucanos e araçaris consomem pelo menos 48 espécies de frutos (Galetti et al. 2000). ...
Resumo: As aves figuram entre os mais importantes dispersores de sementes em praticamente todos os ambientes terrestres. Apesar de serem os vertebrados mais estudados em relação à frugivoria, ainda sabemos muito pouco sobre vários aspectos das relações entre as aves e os frutos. Vários destes aspectos podem ser estudados técnicas simples acessíveis mesmo aos pesquisadores mais inexperientes. Neste capítulo apresentamos algumas destas técnicas, enfatizando seu emprego, vantagens e desvantagens. São apresentadas técnicas relacionadas ao registro de frugivoria, estudo da dieta e movimento das aves, e estudos em cativeiro. Encerramos apontando perspectivas para novos estudos que visam incre-mentar nossa compreensao das relações ecológicas e evolutivas entre as aves frugívoras e seus frutos. Palavras-Chave: interação animal-planta, ornitocoria. outras o consumo de frutos parece ser acidental (e.g., Ardeidae, Aramidae, Threskiornithidae) ou esporádico (e.g., Rallidae, Cathartidae, Alcedini-dae, Falconidae) (veja Moojen et al. 1941, Schub-bart et al. 1965). Enquanto umas poucas espécies de aves são quase que exclusivamente frugívoras (e.g., o guácharo Steatornis caripensis (Steatorni-thidae), Snow 1962; as arapongas Procnias spp. (Cotingidae), Snow 1973), a maioria inclui, além de frutos, outros itens na dieta (e.g., insetos), o que, no entanto, não as impede de serem boas disper-soras de sementes (Blake & Loiselle 1992, Galetti & Guimarães Jr. 2004). Em geral, as aves frugívo-ras exploram uma variedade de espécies de frutos, sem especializarem-se em nenhuma espécie ou família em particular. Wheelwright et al. (1984), por exemplo, registraram 95 espécies de frutos na dieta de Aulacorhynchus prasinus (Ramphastidae), enquanto Worthington (1982, 1983), observou Pi-pra mentalis (Pipridae) se alimentar de mais de 140 espécies na ilha de Barro Colorado no Panamá. Na Mata Atlântica, tucanos e araçaris consomem pelo menos 48 espécies de frutos (Galetti et al. 2000). A ornitocoria, ou seja, a dispersão de sementes por aves ocorre em vários grupos de plantas, desde gimnospermas até angiospermas (van der Pijl 1982). Nas angiospermas, a ornitocoria ocorre tanto em fa-mílias consideradas primitivas (e.g., Magnoliaceae; Aves Frugívoras e seus Frutos
... The difference in seed composition between lek areas nearly 38 km apart suggests that males of different leks forage on different plant species. Between-lek differences in plant phenology and composition, together with the opportunistic feeding habits of manakins that typically consume a wide variety of fruits (Krijger et al. 1997, Loiselle & Blake 1990, Snow 1962, Worthington 1982 likely contributed to the between-lek variability in seed composition. ...
The movement patterns of males, females and juveniles of lekking species often differ due to differences in the commitment to lek activities, which may lead to differences in the spatial distribution and dispersal distances of seeds they eat. By sampling seeds in three lek and non-lek areas of the white-bearded manakin (Manacus manacus), we tested whether this lekking species increased the abundance and species richness of seeds in lek areas and, at a finer scale, in 21 displaying courts within lek areas. Combining data on seed defecation or regurgitation rates by free-ranging individuals, the number of seeds in droppings or regurgitations of mist-netted birds, and the distances travelled by birds equipped with radio-transmitters, we estimated the potential spatial distribution of seeds generated by six resident males and six females or juveniles during the morning peak of lek activity and when lek activity decreased in the afternoon. There was no difference in the species richness (46 and 44 morphospecies, respectively) and abundance of seeds (15.4 ± 7.3 seeds and 14.0 ± 1.1 seeds, respectively) between lek and non-lek areas. Within leks both parameters increased in courts (45 spp., 17.6 ± 14 seeds) compared with non-court sites (22 spp., 1.9 ± 1.8 seeds), likely as a consequence of the longer time spent by resident males in perches in or near display courts. Distances moved by juveniles and females per 60-min period (183 ± 272 m) were greater than resident males (42.6 ± 22.0 m) in the mornings, while the opposite happened in the afternoons (55.2 ± 40.7 m and 157 ± 105 m, respectively). We conclude that the spatial aggregation of seeds in lek areas of M. manacus occurs at the court level, and the spatial distribution of deposited seeds varies with manakin lekking status and the daily period of foraging.
... In particular, manakins are highly transient. Given that manakins are important seed dispersers and heavily frugivorous (Snow 1962a(Snow ,b, 1981Worthington 1982;Wheelwright et al. 1984), I predict that the fruiting of largeseeded understory plants (e.g., Palmae, Psychotria spp.) will coincide with periods of manakin abundance. An alternative hypothesis is that fruiting phenologies may be a cause, not an effect, of manakin transience (Martin and Karr 1986). ...
Whether a bird handles a fruit by crushing it with its bill or simply swallowing it whole has important ramifications for both the dispersal success of the plant and the feeding behavior of the bird. In cage experiments, birds that crushed fruits in their bills ("mashers") usually dropped many seeds without ingesting them. Large seeds were dropped more frequently than small seeds. The proportion of seeds dropped by five tanager species correlated negatively with their body weight. Birds that swallowed fruits whole ("gulpers") did not drop seeds before swallowing fruits. Gulpers regurgitated large seeds and defecated small seeds. Median regurgitation time was less than median defecation time. Gulpers had lower ingestion rates than mashers, probably because mashers did not ingest many seeds. Mashers spent more time than gulpers in handling fruits. Mashers may also be less restricted than gulpers of equivalent size in the sizes of fruits they can take. Plants may respond evolutionarily to the differences in the seed-dispersal probability of mashers and gulpers through different fruit presentation methods, shifted fruiting seasons, seed size, and pericarp texture.
... Our analyses indicate that Painted Honeyeaters timed their departure from the study area in response to the rapid decline in fruit abundance and suggest that breeding is limited by predictable food shortages, as has been suggested for other frugivorous birds (Worthington 1982). The influence of temporal variability in food abundance has been implicated in the timing of breeding for other honeyeaters, e.g. ...
Temporal variation in the onset of breeding has been described for various species in a range of systems. Many of these studies have found a relationship between the timing of breeding and resource levels leading to a matching of life-history stages to resource abundance. However, most of this work has been conducted in northern hemisphere temperate zones – highly regular systems where temperature and other climatic factors have a predictable influence over food abun-dance. We present data gathered over two years on the timing of breeding in a nomadic mistletoe specialist, the Painted Honeyeater (Grantiella picta), relative to temporal variation in the abundance of its main food resource, fruit of the Grey Mistletoe (Amyema quandang), in an Australian semi-arid environment. Arrival and departure of the breeding population occurred either side of peak mistletoe fruiting in both years. Clutches were initiated on average on Day 66 of the breeding season (assigned as 1 October for both years) in 2004 (5 December) and Day 49 (18 November) during 2005, i.e. 17 days earlier in 2005. Abundance of mistletoe fruit peaked in January in both years but increased significantly earlier in 2005. Abundance of fruit was almost identical at the mean clutch initiation dates in both years, reaching comparable levels 19 days earlier in 2005. The timing of life-history stages followed the progression of fruiting phenology and was closely matched to resource levels despite marked differences in the temporal availability of fruit between years. Painted Honey-eaters appear similar to northern hemisphere passerines that use photoperiod to time their overall breeding season and then incorporate information from the local environment to fine-tune initiation of breeding. By cuing directly on the food resource, Painted Honeyeaters may avoid temporal mismatching in this highly unpredictable environment.
... Di¡erences in food availability and in the degree of nest predation have been suggested to act as ultimate factors, concentrating avian breeding in the tropics to certain parts of the year (e.g. Skutch 1950;Morton 1971;Fogden 1972;Snow 1976;Sinclair 1978;Grant & Boag 1980;Worthington 1982;Poulin et al. 1992;Young 1994;Komdeur 1996). In contrast, the proximate environmental factors that regulate breeding events in tropical birds are still largely obscure. ...
Many tropical birds breed seasonally, but it is largely unknown which environmental cues they use to time reproduction. Changes in tropical photoperiod have been regarded as too small to be used as a proximate environmental cue.This hypothesis, however, has never been rigorously tested. Here, we report on experi- mental evidence that photoperiodic changes characteristic of tropical latitudes stimulate reproductive activity in a neotropical bird from the forest understory. In the central Republic of Panama¤ (98N), photo- period varies annually between 12 hours (December) and 13 hours (June). Free-living spotted antbirds (Hylophylax n. naevioides) had regressed gonads in December, but increased gonads ahead of the rainy (the breeding) season in May. Captive spotted antbirds exposed to a 'long' photoperiod of 13 hours increased gonadal size eight-fold and song activity six-fold over that of control birds remaining on a simulated 'short' photoperiod of 12 hours of daylight. Moreover, even a photoperiod of 12 hours 17 minutes was su⁄cient to stimulate gonadal growth in photostimulated birds over that of controls.The dramatic changes in gonadal development were not accompanied by similar changes in hormone titres such as luteinizing hormone and testosterone as expected from temperate zone birds.We propose a more general role of the tropical photo- period in the regulation of seasonal events in tropical organisms, or in temperate zone species migrating to the tropics.
A complete nesting information is available for 7.8% of the Manakin species; however, most of this information is fragmented and available mainly for lowland species. Hence, nesting information for highland species is scattered. Our study presents nesting information on a cloud forest Manakin species, the Golden-winged Manakin (Masius chrysopterus), which is distributed from western Colombia to northern Peru between 1000 and 2300m. We monitored 10 nests, from February through July in 2014 and 2015 at Parque Nacional Natural Tatamá, Colombia. We describe the nest, egg, and nestling, and provide information on incubation behavior and nestling feeding. The cup nest was similar to those found in most manakins. Eggs were creamy with brown spots concentrated at the base and measured 8.70± 0.89mm x 13.30 ± 0.39mm. The nestling growth rate (K) was 0.38. The incubation and nestling period were 22 and 16 days, respectively. The female conducted 70 off-bout trips day-1 that lasted on average 8.24 ± 5.44min, with 78% nest attentiveness. This study provides the most complete nesting data for a cloud forest manakin. Overall, M. chrysopterus incubation and nestling period are longer when compared to other manakin species. But the nest structure and composition, and eggs coloration concurred with other species.
Lekking is classified as a form of male-dominance polygyny in which males lack control of resources essential for the acquisition of females. Of particular interest to behavioral ecologists has been the mechanistic basis of male spatial aggregation and the maintenance of site fidelity over time. The “hotspot” hypothesis has been proposed as both an ultimate and proximate mechanism by which males aggregate in locations where females are likely to be encountered. The hypothesis has been extended to include areas of the environment that act to constrain females’ use of space. Here, we test a prediction of this hypothesis for three species of manakins (Pipridae): that leks are located in places where fruit, the main food for these frugivorous birds, is plentiful. We compared four lek sites with four non-lek control sites of Golden-headed (Pipra erythrocephala), Wire-tailed (P. filicauda), and White-crowned (P. pipra) manakins in an Amazonian forest in Ecuador. Our results show that lek sites had higher fruit biomass than control sites. Moreover, lek sites had more plants bearing ripe fruit as well as a higher fruit biomass per plant than control sites. Thus, our results support the environmental hotspot hypothesis as an explanation for current lek site occupancy and suggest that fruit availability may also explain the placement of traditional manakin lekking sites. We also discuss a potential direct benefit for subordinate male manakins derived from the notion of central-place foraging and public information-sharing.
Una Prueba de la Hipótesis de que Puntos que Concentran Recursos Explican la Ubicación de las Asambleas de Cortejo en Tres Especies de Saltarines (Pipridae) en Ecuador
Phylogenetic analyses of lekking, lek spatial organization, and cooperative and coordinated lek display in the manakins (Aves: Pipridae) demonstrate that variation in social behavior in the group has a strong, phylogenetic component. Two of the three classes of social behavior examined also show significant phylogenetic constraints. Current adaptive plasticity models are insufficient to explain the phylogenetic variation in these behaviors in the manakins. These findings support the conclusion that vertebrate reproductive social behavior has an evolutionary history, and that it is not determined solely by adaptive individual plasticity to current conditions. The evolution of social behavior, particularly through sexual selection, can have historical consequences that can limit subsequent behavioral adaptation.
The dispersal of seeds from Asarum canadense by ants was studied to quantify variation in mutualistic benefits and to test the hypothesis that this mutualism has effects on population density. Six populations of A. canadense were monitored in SE West Virginia, in the Monongahela National Forest. The rate of seed removal, dispersal distance, microhabitats of dispersed seeds and disperser species were determined in each study site. I measured ovule production and factors causing loss of ovules and the seeds resulting from them through the stage of dispersed seeds. The proportion of seeds removed from the area under the parent plant was the best indicator of dispersal benefits. Few components of dispersal varied among the six sites, but significant variation was observed for capsule formation, ovule development, and pre-dispersal seed predation. Key factor analysis showed pre-dispersal seed predation to be the major factor influencing spatial variation in seed production. Seedling density in 1984 was directly related to seed production in 1983. No population feedback for mutualism was detected.
Most frugivorous birds in E North America are only partly and/or seasonally so, and many North American plants whose seeds are dispersed by birds also have considerable dispersal of seeds by frugivorous (or granivorous) mammals or tortoises, or sometimes by abiotic means. The relatoinship of bird dispersal to plant population dynamics, competition for dispersal agents and habitat breadth is treated, followed by a consideration of the relationship of avian frugivory to bird population dynamics, competition for fruits and habitat breadth. Plant composition, in terms of the percentage of the flora that is bird dispersed, is compared for different geographic segments of E North America and for different kinds of communities. Relative abundance of bird-dispersed plants is compared for certain areas. Bird community composition, relative abundance and density are compared, during the breeding season and during winter, among geographic regions and among habitats.-from Author
Bird-dispersed plants of the tropical rain forest understory are widely spaced and produce sparse crops (most with fewer than 10 ripe fruits available at any one time). Such plants probably disperse the greatest proportion of their lifetime output of seeds in the short periods during which they occur in treefall gaps. There, environmental conditions stimulate the production of large crops of fruit. At the same time, however, competition for dispersers is also likely to be high because of the proximity of other fruiting plants in the same clearings. For birddispersed shrubs and treelets, treefall clearings thus represent both critical opportunities for fruit production and seed dispersal and effective bottlenecks of increased competitive pressure from other fruiting plants.
The assessment of fruit abundance is critical for studies of frugivore ecology A variety of methods have been used to estimate habitat-wide fruit abundance. However, since the methods have not been calibrated with each other, it is difficult to compare results of different studies. Here we compare three methods used simultaneously to collect fruit abundance data in the Kibale Forest, Uganda. Estimates of fruit abundance derived from fruit traps were not correlated with estimates derived from either systematic transect sampling or estimates obtained from observing fruiting phenology of key species on a fruit trail. However, estimates based on fruit trail data and transect data were correlated. We review the advantages and disadvantages of methods that have been used to assess habitat-wide fruit abundance.
We studied temporal fluctuations in fruit production by plants and in populations of understory fruit-eating birds at three elevations (50, 500, and 1000 m) in Costa Rican wet forests over a 12-16 mo period to investigate effects of resource variation on bird movements and community structure. We used mist nets to monitor changes in frugivore abundance, migration patterns, and breeding and molting cycles. We sampled understory fruits of each forest concurrent with studies of frugivores. Both frugivores and fruit exhibited considerable seasonal variation in abundance. Peak frugivore capture rates occurred during peak periods of ripe fruit abundance. Altitudinal migrants left lower montane (1000 m) forest during periods of fruit scarcity and wee present in lowland (50 m) and foothill (500 m) forest when ripe fruit was abundant. Migrants, both altitudinal and temperate, accumulated fat before migration, and perhaps (for altitudinal migrants) in anticipation of breeding. Some residents also put on fat before breeding. Breeding was seasonal at all forests and occurred when ripe fruit abundance was low. Results of this study indicate that birds may track changes in resource abundance. Thus, variation in resource abundance influences dynamics of bird communities, both in terms of species composition and abundance. Further, results illustrate the importance of viewing communities from different scales; dynamics at a local scale (e.g., one elevation) can be influenced by changes in conditions (e.g., fruit abundance) elsewhere. That some species regularly moved along elevational gradients implies that preservation of many species and of the biotic integrity of entire systems may require conservation of large, connected blocks of suitable habitat.
Red-capped Manakins (Pipra mentalis) and Golden-collared Manakins (Manacus vitellinus), two species of small, frugivorous, tropical passerines, showed facultative hypothermia and reduced oxygen consumption at night. The lowest body temperature measured in M. vitellinus (30.5°C, when the ambient temperature was 19.5°C) represents a reduction of more than 40% in the difference between body temperature and ambient temperature. Under these circumstances, a reduction of more than 40% in the rate of oxygen consumption would also occur during the period of regulated hypothermia. Even moderate hypothermia at ambient temperatures typical of the lowland tropics substantially reduces the energy expenditure of a resting bird.
A review, offering new interpretations, is made of a vast and heterogeneous literature related to the mutualism between frugivores and plants in tropical forests. The subject is detached in three sections: (a) paleobiological aspects, impact on biodiversification during geological time; (b) autoecologies, modeling of the bioeconomies of participating organisms; (c) community role, maintenance of the structure and biodiversity of extant communities. The section on paleobiological aspects is based on the argument that the dominance of angiosperms from the Cretaceous onwards could be the result of a synergism between two interactions characterizing these plants: mutualisms with nectarivores and frugivores. The section on autecologies is organized around three attributes of fruits: phenology, spatial distribution, quality. Phenology, in a scale of months, considered separately, introduces us to the study of seasonal rhythms. Frugivores respond to the seasonal shortage of fruit by showing a high diversity of strategies, the most common being seasonal reproduction. Although phenology is conditioned mainly by climate, frugivores also have a repercussion on it. There are two approaches to the study of this repercussion: that of SNOW, at an interspecific level, here reduced to a particular case of four possible ones; that of HOWE and ESTABROOK, at an intraspecific level, here corrected and complemented. Phenology, in a scale of days, considered together with spatial distribution and quality, introduces us to the study of the foraging strategies of frugivores. There are two schemes for classifying these strategies: that of birds, based on the quality factor; that of bats, based on the spatiotemporal (spatial + phenological) factor. Here both schemes are amended and merged. The result is the first unified scheme for the foraging strategies of frugivorous birds and bats. Such a unified scheme is also valid for the foraging strategies of nonflying frugivores, the opportunity being taken to apply it to primates. The section on community role recognizes two levels of analysis: the first concerns the functions of seed dispersal in maintaining patterns of spatial distribution of plants; the second is based on evaluating the functional importance of frugivores and their coadapted plants in the trophic webs to which they belong.
Manakins are prominent fruit-eaters and seed dispersers in the Neotropics. Most manakin species establish lek areas where males devote long periods of time displaying to attract mates, interspersed with brief absences to feed on fruits located near lek areas. We compared the frequency of visits to plants, fruit handling behavior, and number of fruits ingested by the lek-forming Manacus manacus (White-bearded Manakin) and species of non-lekking birds in two species of fruiting trees (Miconia rigidiuscula and Ocotea pulchella) in lek and non-lek areas during the lek and non-lek periods of M. manacus in a threatened Atlantic forest ecosystem. During the non-lek season, M. manacus and non-lekking birds did not differ in the frequency of visits to Miconia trees near lek and non-lek areas. However, M. manacus swallowed a higher number of fruits near leks than non-lekking birds, while the opposite was true in non-lek areas. During the lek season, M. manacus visited Ocotea trees more frequently and swallowed more fruits than non-lekking birds in lek areas.
I studied the foraging behavior and diet of the Helmeted Manakin (Antilophia galeata) in the gallery forests in the cerrado (savanna) region of central Brazil. Observations of 21 color-marked birds were made from April 1988 to March 1989 on a 2.5-ha study plot in a gallery forest. They showed that Helmeted Manakins are highly frugivorous (85.7% of foraging observations were on fruits; all stomach contents analyzed had fruits while arthro-pods were present in only 24.5%; and 96.2% of the fecal masses collected under a nest had fruits while 6 1.5% had arthropods); and take fruit mostly (46.5% of the observations) while in flight (sallies). Helmeted Manakins ate fruits of 17 species of 12 families of plants, as well as arthropods such as Araneae, Orthoptera, Coleoptera, Diptera, and Hymenoptera. One to six Helmeted Manakins attended 63.6% of the mixed-species flocks observed. Green birds (females and immature males) foraged at lower heights (6.5 * 4.6 m) than adult and subadult males, which foraged at a height (8.2 f 4.4 m) closer to where they sang (10.2 + 3.8 m) or called (8.4 f 4.8 m). The Helmeted Manakin showed similarities to other manakins in the diet and foraging tactics used, even though it may not be promiscuous (Marini and Cavalcanti, in prep.) and has an unique geographical distribution among dichromatic man-akins.
Though the harmful effects anthropogenic disturbances pose to wild primates are well appreciated, comparatively little is known about the effects of natural disturbances. From December 2010 to January 2011, different mortality patterns were observed for two primate species, capuchins and howler monkeys, on Barro Colorado Island (BCI), Panama. Unusually high rainfall in 2010 was associated with census and cadaver data indicating the rapid loss of >70% of the capuchin population in late 2010 to early 2011. In contrast, over this same period, no decline was documented for howler monkeys and cadaver data for howlers was unexceptional. The high mortality experienced by the capuchin population was unexpected and its extent was not fully appreciated until the event was largely over. Explanations proposed for it included effects of hypothermia, disease or a shortage of some essential nutrient(s). Of these, the dietary explanation seems most probable. BCI capuchins depend most heavily on arthropod foods in December, when few higher quality ripe fruits are available. The unprecedented high rainfall in December 2010 is hypothesized to have largely eliminated the arthropod peak expected on BCI each December. A lack of protein-rich arthropods, when coupled with the climatic and nutritional stress capuchins generally experience at this time of year, appears to have precipitated the rapid die-off of most of the island's capuchin population. As howler monkeys obtain dietary protein primarily from leaves, a shortage of edible arthropods would not affect howler numbers. Comparison of our 2010 data with similar data on earlier primate/mammalian mortality events reported for BCI and for Corcovado, Costa Rica indicates that our understanding of the effects of natural disturbances on wild primate populations is not profound. We suggest that more research be devoted to this increasingly timely topic, so important to conservation policy. Am. J. Primatol. © 2013 Wiley Periodicals, Inc.
We investigated the spatial pattern of tree recruitment 15 years after clear-cutting in two logged strips in the Peruvian Amazon, focusing on differences between seed dispersal modes and cohorts, and relating these to spatial patterns of seed dispersal in the years immediately following clearing. Most trees that recruited in logged strips belonged to taxa dispersed by birds or nonvolant mammals, with smaller numbers dispersed by bats or wind. Seed dispersal patterns differed, with few mammal-dispersed seeds reaching strips, bird-dispersed seeds more abundant near the forest edge than strip centers, and bat- and wind-dispersed seeds more evenly distributed. However, this pattern was not reflected in the tree recruits, except in the deferment cut half of strip 2. Different dispersal modes were differentially represented in different cohorts; for example, in strip 1 bird-dispersed trees predominated in early cohorts, while trees dispersed by nonvolant mammals predominated in later cohorts. Our finding that trees dispersed by mammals (which disperse the majority of commercial trees in Amazonia) successfully regenerate from seed in the interior of logged strips highlights the value of maintaining these animals in forest management systems.
Phylogenetic systematic methods were applied in an investigation of the evolution of lek display behavior in the Neotropical manakins (Aves: Pipridae). Results of a previous investigation of the syringeal morphology of manakins were used as a behaviorally independent estimate of the phylogeny of the family. Three phylogenetic analyses of 44 display characters wer
In a Costa Rican tropical wet forest community, of species with adequate sample sizes, 40% of bird species (17 of 42) and 30% of fruiting plant species (10 of 33) were found significantly more often in gaps than in intact forest. Only 5% of the bird species (2 of 42) and no plant species were found significantly more often in intact forest sites. Frugivorous and nectarivorous bird species were especially common in gaps. Birds of second-growth and forest edge were proportionately more abundant in gaps than were birds of forest interior. Canopy birds were not prevalent in gaps. Plants in gaps tended to produce more fruit over a longer period than conspecifics fruiting under a closed canopy. Large gaps had higher densities of fruiting plants and fruit-eating birds than small gaps. Gaps thus may be important sources of fruit during periods of fruit scarcity. Given the high density of fruit-eating birds in gaps, seed deposition patterns generated by these birds was probably nonrandom, and seeds may be dispersed into or around the periphery of gaps more often than into closed understory sites. Thus, fruiting shrub density affects the distribution of fruit-eating birds, which then influences the distribution of fruiting plants and birds in the next generation. -from Author
A lek is a cluster of males on display territories. Despite the
attention that lek mating systems have received, the factors involved in
lek evolution are still poorly understood. The `hotspot' hypothesis
suggests that population level patterns of female movement and/or
dispersion determine male settlement patterns. Males, it is argued,
should settle where females are most likely to be encountered or where
female densities are greatest. Leks occur as a result of marked
heterogeneities in female distributions. I tested three novel
interspecific predictions of the hotspot hypothesis: (i) the leks of
ecologically similar, sympatric species should be clustered; (ii) the
degree of this clustering should be related to the degree of similarity
in diet between the species; and (iii) species with similar diets should
show correlated changes in the sizes of neighbouring leks. I documented
the size and locations of leks of four neotropical bird species over 4
years. All three of the predictions were confirmed. The interspecific
aggregation of leks strongly suggests a role of hotspot mechanisms in
the evolution of lekking in these species.
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