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Thomas H. Kunz - One of the best experts on this subject based on the ideXlab platform.
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social organization and genetic structure insights from codistributed bat populations
Molecular Ecology, 2012Co-Authors: Stephen J Rossiter, Adura Mohdadnan, Matthew J Struebig, Eric J Petit, Thomas H. Kunz, Akbar Zubaid, Sucharita Gopal, Tigga KingstonAbstract:The impact of ecology and social organization on genetic structure at landscape spatial scales, where gene dynamics shape evolution as well as determine susceptibility to habitat fragmentation, is poorly understood. Attempts to assess these effects must take into account the potentially confounding effects of history. We used microsatellites to compare genetic structure in seven bat species with contrasting patterns of Roosting ecology and social organization, all of which are codistributed in an ancient forest habitat that has been exceptionally buffered from radical habitat shifts. Over one thousand individuals were captured at foraging sites and genotyped at polymorphic microsatellite loci. Analyses of spatially explicit genotype data revealed interspecies differences in the extent of movement and gene flow and genetic structure across continuous intact forest. Highest positive genetic structure was observed in tree-Roosting taxa that roost either alone or in small groups. By comparison, a complete absence of genetic autocorrelation was noted in the cave-Roosting colonial species across the study area. Our results thus reveal measurable interspecies differences in the natural limits of gene flow in an unmodified habitat, which we attribute to contrasting Roosting ecology and social organization. The consequences of ecology and behaviour for gene flow have important implications for conservation. In particular, tree-Roosting species characterized by lower vagility and thus gene flow will be disproportionally impacted by landscape-scale forest clearance and habitat fragmentation, which are prevalent in the study region. Our method also highlights the usefulness of rapid sampling of foraging bats for assaying genetic structure, particularly where Roosting sites are not always known.
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mating system of the tent making bat artibeus watsoni chiroptera phyllostomidae
Journal of Mammalogy, 2008Co-Authors: Gloriana Chaverri, Christopher J Schneider, Thomas H. KunzAbstract:Vertebrate mating systems are influenced by ecological and phylogenetic factors, and the variation observed in mating behavior is frequently attributable to the extent to which male assistance in the rearing of offspring increases a female’s reproductive rate, size and stability of female groups, and density and distribution of females in space. In this study we evaluate patterns of association and parentage to describe the mating system of the tentmaking bat Artibeus watsoni. During 16 consecutive months, we regularly surveyed 2 sites in southwestern Costa Rica and determined size, composition, and stability of social groups, and established patterns of parentage within roosts. We found female-biased, mixed-sex social groups formed by individuals located in several roosts within an area. Roosting associations were low (average across all sites: 31%), and the frequent changes between Roosting partners suggests that males and females formed nonexclusive mating bonds, which was further supported by our finding that only 27% of young were sired by the male within a Roosting group. Paternal sibships were only observed in 17% of dyads of young Roosting together, indicating that few males copulated with .1 female of the Roosting group during the mating season. However, paternal sibships were only observed in Golfito, which could be explained by greater group size and stability attributable to lower roost availability. Thus, our findings are consistent with a polygynandrous mating system (2 or several males sharing access to 2 or several females, and vice versa) in which males associated intermittently with females that frequently switched roosts, and where breeding opportunities for males seemed related to the defense of roosts, Roosting territories, or both.
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Roosting behavior and group stability of the big fruit eating bat artibeus lituratus chiroptera phyllostomidae
Mammalian Biology, 2008Co-Authors: Mariana Munozromo, Emilio A Herrera, Thomas H. KunzAbstract:The Roosting behavior of the big fruit-eating bat, Artibeus lituratus (Phyllostomidae, Stenodermatinae) in an Andean region of Venezuela is described. Sixty-four video recordings made at three separate foliage roosts during 1 year showed that group size varied between two and 14 individuals. One male was regularly observed Roosting with more females than others, and this male was associated with the highest quality roost, defined here as the highest, most structurally stable, and least disturbed. Males invariably occupied exclusive roosts during the study, whereas females frequently moved among adjacent roosts. The high roost fidelity of males appears to be related to the defense of the highest quality roosts. Because females were observed Roosting with each of the three males present at the study site, female groups were considered unstable. We suggest that shuttling movements of individuals may reflect a commonly observed adaptation of foliage Roosting bats related to the avoidance of predators and/or parasites. The type of male–female association observed in A. lituratus is consistent with a resource defense polygyny hypothesis.
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ecological correlates of range size in the tent making bat artibeus watsoni
Journal of Mammalogy, 2007Co-Authors: Gloriana Chaverri, Oscar E Quiros, Thomas H. KunzAbstract:We examined variation in foraging- and Roosting-range size in the tent-making bat Artibeus watsoni .W e radiotracked 42 individuals at 2 sites in the Golfito Wildlife Refuge and 6 sites at Corcovado National Park, southwestern Costa Rica. Average home-range size of A. watsoni was the smallest recorded for a bat species (3.6 ha). Site, age, reproductive status, habitat, and season all had significant effects on foraging ranges, but sex and population abundance did not. Bats from the most productive sites, such as primary forests, had smaller foraging ranges, and subadults ranged farther than adults. During the dry season, females in late pregnancy had the smallest foraging ranges of all, most likely as a result of flight constraints imposed by the large fetus and an increase in fruit availability. Conversely, lactating females sampled during the early rainy season had among the largest foraging ranges. Males had significantly smaller Roosting ranges than females, and adult bats sampled from areas of low roost abundance and high population abundance had smaller Roosting ranges. However, subadults appeared to be unaffected by such changes in resource abundance, perhaps because they often roost in unmodified leaves. Although differences in resource availability and competition were important in determining Roosting-range size, these effects were concealed by effects of reproductive activities such as mating, pregnancy, and lactation. Reproductive condition, along with foraging and Roosting resource abundance, were largely responsible for determining ranging patterns in A. watsoni, but factors influenced foraging- and Roosting-range size in different ways.
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range overlap and association patterns in the tent making bat artibeus watsoni
Animal Behaviour, 2007Co-Authors: Gloriana Chaverri, Melquisedec Gambarios, Thomas H. KunzAbstract:Space use and ranging patterns of individuals have traditionally been used to identify social systems, and the amount of overlap in the home ranges of individuals can provide indirect information about the likelihood of social interactions. We compared data on foraging and Roosting range overlap of the tent-Roosting bat Artibeus watsoni to assess how environmental and demographic factors may affect movement patterns and social interactions. We estimated the overlap of foraging and Roosting ranges among simultaneously radiotagged dyads and calculated a simple association index among these individuals. We then used these data to determine whether relative population and roost abundance, as well as sex class, affected spatial and social patterns. Our results show that range overlap in A. watsoni significantly determines the degree to which individuals interact with each other. We also found that Roosting range overlap may be a greater determinant of daytime social interactions than foraging range overlap, because Roosting range overlap showed a stronger correlation with association patterns. In addition, the differences that we observed in Roosting range overlap and association among dyads were a consequence of the effects of population and roost density. Bats sampled in areas of high-population abundance had significantly higher Roosting range overlap than bats in areas of low-population abundance, and Roosting ranges of bats sampled at sites with few Roosting resources (i.e. tents) overlapped more than those of bats living in areas with more tents. Finally, we observed no overlap in Roosting range and no association among adult males, supporting the hypothesis that males defend tents or Roosting areas against other males to gain exclusive mating access to females using these structures.
Gloriana Chaverri - One of the best experts on this subject based on the ideXlab platform.
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social calls used by a leaf Roosting bat to signal location
Biology Letters, 2010Co-Authors: Gloriana Chaverri, Erin H Gillam, Maarten J VonhofAbstract:Social calls in bats have many functions, including mate attraction and maintaining contact during flight. Research suggests that social calls may also be used to transfer information about roosts, but no studies have yet demonstrated that calls are used to actively attract conspecifics to Roosting locations. We document the social calls used by Spix9s disc-winged bat ( Thyroptera tricolor ) to actively recruit group members to roosts. In acoustic trials, we recorded two sets of calls; one from flying individuals termed ‘inquiry calls’, and another from Roosting bats termed ‘response calls’. Inquiry calls were emitted by flying bats immediately upon release, and quickly (i.e. 178 ms) elicited production of response calls from Roosting individuals. Most flying bats entered the roost when Roosting individuals responded, while few bats entered the roost in the absence of a response. We argue that information transfer concerning roost location may facilitate sociality in T. tricolor , given the ephemeral nature of Roosting structures used by this species.
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mating system of the tent making bat artibeus watsoni chiroptera phyllostomidae
Journal of Mammalogy, 2008Co-Authors: Gloriana Chaverri, Christopher J Schneider, Thomas H. KunzAbstract:Vertebrate mating systems are influenced by ecological and phylogenetic factors, and the variation observed in mating behavior is frequently attributable to the extent to which male assistance in the rearing of offspring increases a female’s reproductive rate, size and stability of female groups, and density and distribution of females in space. In this study we evaluate patterns of association and parentage to describe the mating system of the tentmaking bat Artibeus watsoni. During 16 consecutive months, we regularly surveyed 2 sites in southwestern Costa Rica and determined size, composition, and stability of social groups, and established patterns of parentage within roosts. We found female-biased, mixed-sex social groups formed by individuals located in several roosts within an area. Roosting associations were low (average across all sites: 31%), and the frequent changes between Roosting partners suggests that males and females formed nonexclusive mating bonds, which was further supported by our finding that only 27% of young were sired by the male within a Roosting group. Paternal sibships were only observed in 17% of dyads of young Roosting together, indicating that few males copulated with .1 female of the Roosting group during the mating season. However, paternal sibships were only observed in Golfito, which could be explained by greater group size and stability attributable to lower roost availability. Thus, our findings are consistent with a polygynandrous mating system (2 or several males sharing access to 2 or several females, and vice versa) in which males associated intermittently with females that frequently switched roosts, and where breeding opportunities for males seemed related to the defense of roosts, Roosting territories, or both.
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ecological correlates of range size in the tent making bat artibeus watsoni
Journal of Mammalogy, 2007Co-Authors: Gloriana Chaverri, Oscar E Quiros, Thomas H. KunzAbstract:We examined variation in foraging- and Roosting-range size in the tent-making bat Artibeus watsoni .W e radiotracked 42 individuals at 2 sites in the Golfito Wildlife Refuge and 6 sites at Corcovado National Park, southwestern Costa Rica. Average home-range size of A. watsoni was the smallest recorded for a bat species (3.6 ha). Site, age, reproductive status, habitat, and season all had significant effects on foraging ranges, but sex and population abundance did not. Bats from the most productive sites, such as primary forests, had smaller foraging ranges, and subadults ranged farther than adults. During the dry season, females in late pregnancy had the smallest foraging ranges of all, most likely as a result of flight constraints imposed by the large fetus and an increase in fruit availability. Conversely, lactating females sampled during the early rainy season had among the largest foraging ranges. Males had significantly smaller Roosting ranges than females, and adult bats sampled from areas of low roost abundance and high population abundance had smaller Roosting ranges. However, subadults appeared to be unaffected by such changes in resource abundance, perhaps because they often roost in unmodified leaves. Although differences in resource availability and competition were important in determining Roosting-range size, these effects were concealed by effects of reproductive activities such as mating, pregnancy, and lactation. Reproductive condition, along with foraging and Roosting resource abundance, were largely responsible for determining ranging patterns in A. watsoni, but factors influenced foraging- and Roosting-range size in different ways.
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range overlap and association patterns in the tent making bat artibeus watsoni
Animal Behaviour, 2007Co-Authors: Gloriana Chaverri, Melquisedec Gambarios, Thomas H. KunzAbstract:Space use and ranging patterns of individuals have traditionally been used to identify social systems, and the amount of overlap in the home ranges of individuals can provide indirect information about the likelihood of social interactions. We compared data on foraging and Roosting range overlap of the tent-Roosting bat Artibeus watsoni to assess how environmental and demographic factors may affect movement patterns and social interactions. We estimated the overlap of foraging and Roosting ranges among simultaneously radiotagged dyads and calculated a simple association index among these individuals. We then used these data to determine whether relative population and roost abundance, as well as sex class, affected spatial and social patterns. Our results show that range overlap in A. watsoni significantly determines the degree to which individuals interact with each other. We also found that Roosting range overlap may be a greater determinant of daytime social interactions than foraging range overlap, because Roosting range overlap showed a stronger correlation with association patterns. In addition, the differences that we observed in Roosting range overlap and association among dyads were a consequence of the effects of population and roost density. Bats sampled in areas of high-population abundance had significantly higher Roosting range overlap than bats in areas of low-population abundance, and Roosting ranges of bats sampled at sites with few Roosting resources (i.e. tents) overlapped more than those of bats living in areas with more tents. Finally, we observed no overlap in Roosting range and no association among adult males, supporting the hypothesis that males defend tents or Roosting areas against other males to gain exclusive mating access to females using these structures.
Christopher Turbill - One of the best experts on this subject based on the ideXlab platform.
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winter activity of australian tree Roosting bats influence of temperature and climatic patterns
Journal of Zoology, 2008Co-Authors: Christopher TurbillAbstract:Many bats hibernate to overcome a critical energy shortage in winter. However, unlike strictly seasonal hibernators, bats sometimes alternate prolonged torpor bouts with increased activity coinciding with periods of mild weather. Winter activity may be especially common in hibernating tree-Roosting bats because they are less insulated from external conditions than cave-Roosting species and must also leave their roosts to drink, socialize or mate. To test this hypothesis, I measured the activity of a community of tree-Roosting bats by recording echolocation calls at four sites on 18 nights throughout winter in south-eastern Australia. I also measured insect activity using light traps at each site. I recorded some bat activity on most nights, typically at dusk. Greater bat and insect activity occurred on nights of warmer temperatures, moderate wind speeds and falling barometric pressure, indicating the approach of low-pressure cold fronts. Thus, winter activity of tree-Roosting bats is linked to short-term mild conditions caused by a specific, reoccurring weather pattern. Climatic shifts that reduce the frequency of such weather events, such as the El Nino Southern Oscillation phenomenon and future human-induced climate change, may also reduce winter activity and/or increase the cost of necessary arousal periods by hibernating tree-Roosting bats.
Kevin J Olival - One of the best experts on this subject based on the ideXlab platform.
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a comparative analysis of viral richness and viral sharing in cave Roosting bats
Diversity, 2017Co-Authors: Anna R Willoughby, Kendra L Phelps, Kevin J OlivalAbstract:Caves provide critical Roosting habitats for bats globally, but are increasingly disturbed or destroyed by human activities such as tourism and extractive industries. In addition to degrading the habitats of cave-Roosting bats, such activities often promote contact between humans and bats, which may have potential impacts on human health. Cave-Roosting bats are hosts to diverse viruses, some of which emerged in humans with severe consequences (e.g., severe acute respiratory syndrome coronavirus and Marburg virus). Characterizing patterns of viral richness and sharing among bat species are therefore important first steps for understanding bat-virus dynamics and mitigating future bat-human spillover. Here we compile a database of bat-virus associations and bat species ecological traits, and investigate the importance of Roosting behavior as a determinant of viral richness and viral sharing among bat species. We show that cave-Roosting species do not host greater viral richness, when accounting for publication bias, diet, body mass, and geographic range size. Our global analyses, however, show that cave-Roosting bats do exhibit a greater likelihood of viral sharing, especially those documented in the literature as co-Roosting in the same cave. We highlight the importance of caves as critical foci for bat conservation, as well as ideal sites for longitudinal surveillance of bat-virus dynamics.
Akbar Zubaid - One of the best experts on this subject based on the ideXlab platform.
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social organization and genetic structure insights from codistributed bat populations
Molecular Ecology, 2012Co-Authors: Stephen J Rossiter, Adura Mohdadnan, Matthew J Struebig, Eric J Petit, Thomas H. Kunz, Akbar Zubaid, Sucharita Gopal, Tigga KingstonAbstract:The impact of ecology and social organization on genetic structure at landscape spatial scales, where gene dynamics shape evolution as well as determine susceptibility to habitat fragmentation, is poorly understood. Attempts to assess these effects must take into account the potentially confounding effects of history. We used microsatellites to compare genetic structure in seven bat species with contrasting patterns of Roosting ecology and social organization, all of which are codistributed in an ancient forest habitat that has been exceptionally buffered from radical habitat shifts. Over one thousand individuals were captured at foraging sites and genotyped at polymorphic microsatellite loci. Analyses of spatially explicit genotype data revealed interspecies differences in the extent of movement and gene flow and genetic structure across continuous intact forest. Highest positive genetic structure was observed in tree-Roosting taxa that roost either alone or in small groups. By comparison, a complete absence of genetic autocorrelation was noted in the cave-Roosting colonial species across the study area. Our results thus reveal measurable interspecies differences in the natural limits of gene flow in an unmodified habitat, which we attribute to contrasting Roosting ecology and social organization. The consequences of ecology and behaviour for gene flow have important implications for conservation. In particular, tree-Roosting species characterized by lower vagility and thus gene flow will be disproportionally impacted by landscape-scale forest clearance and habitat fragmentation, which are prevalent in the study region. Our method also highlights the usefulness of rapid sampling of foraging bats for assaying genetic structure, particularly where Roosting sites are not always known.
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comparative Roosting ecology of cynopterus chiroptera pteropodidae fruit bats in peninsular malaysia
Biotropica, 2006Co-Authors: Polly Campbell, Akbar Zubaid, Noah M Reid, Adura M Adnan, Thomas H. KunzAbstract:Although the use of modified roosts has been reported in more than 20 species of bats in the tropics, comparative studies of the Roosting ecology of congeneric tent-Roosting species are notably lacking. In the Paleotropics, this unique behavior has been described in two species belonging to the genus, Cynopterus: C. sphinx and C. brachyotis. However, it is not known whether tent Roosting is an essential component of their Roosting ecology, or whether the behavior is found in other members of the genus. In this study we characterize the Roosting ecology of four sympatric species of Cynopterus in peninsular Malaysia and use these data to address two main questions. (1) Do all four species use modified roosts and, in those that do, is tent-Roosting obligate or opportunistic? (2) Do species pairs overlap in roost preferences and Roosting habitat and, if so, is there evidence for interspecific interactions in relation to these resources? We radio-tracked bats at two floristically distinct sites and located a total of 249 roosts. Interspecific roost niche overlap was minimal at both sites and we found no evidence for interspecific competition for roost resources at the local level. Species differences in Roosting ecology were defined primarily by spatial separation of Roosting habitats and secondarily by within-habitat differences in roost selection. Importantly, we found that although periodic use of modified roosts was a characteristic shared by all four species, most roosts were unmodified, indicating that tent Roosting is a facultative behavior in Malaysian Cynopterus.