The Experts below are selected from a list of 234 Experts worldwide ranked by ideXlab platform
Aaron P Wagner - One of the best experts on this subject based on the ideXlab platform.
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Genetic relatedness and space use in two populations of Striped Hyenas (Hyaena hyaena)
Journal of Mammalogy, 2019Co-Authors: Katy J. Califf, Aaron P Wagner, David S. Green, Kim T. Scribner, Karen Beatty, Meredith E. Wagner, Kay E. HolekampAbstract:Surprising social complexity and variability have recently been documented in several mammalian species once believed to be strictly solitary, and variation in resource abundance may drive this variation in sociality. Wagner et al. (Wagner, A. P., S. Creel, L. G. Frank, and S. T. Kalinowski. 2007. Patterns of relatedness and parentage in an asocial, polyandrous Striped Hyena population. Molecular Ecology 16:4356–4369) reported unusual space-use patterns among female Striped Hyenas (Hyaena hyaena) in central Kenya, where pairwise relatedness among females increased with the geographic distance separating them. The authors suggested that this pattern, very rare among mammals, might reflect attempts by females to avoid competition with close relatives for scarce resources in areas of range overlap. Here, we compare those data to new data, documenting genetic relatedness and space use in a previously unstudied wild population of Striped Hyenas in southern Kenya. We tested hypotheses suggesting that resource abundance and population density affect patterns of genetic relatedness and geographic distance in this species. Our results suggest that higher per capita prey density results in relaxed competition for food, and greater social tolerance among female Striped Hyenas. A hypothesis suggesting lower population density in the southern population was not supported. Relaxed resource competition also may lead to female–female cooperation in the southern population; we documented for the first time behavioral evidence of den sharing by adult female Striped Hyenas. Our data indicate that different populations of this little-studied species exhibit behavioral plasticity; in this case, markedly different space-use patterns and patterns of spatial relatedness under different ecological conditions.
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Age-Related Variation in the Scent Pouch Bacterial Communities of Striped Hyenas ( Hyaena hyaena )
Chemical Signals in Vertebrates 13, 2016Co-Authors: Kevin R. Theis, Aaron P Wagner, Kay E. Holekamp, Arvind Venkataraman, Thomas M. SchmidtAbstract:Our understanding of the contributions of symbiotic microbes to animal behavior is being greatly facilitated by technological advances in characterizing host-associated microbial communities and their synergistic metabolic activities. A particularly promising line of inquiry is to elucidate how symbiotic microbes can mediate animals’ chemical communication systems. Using a combination of next-generation DNA sequencing and targeted metabolite analyses, we recently found that symbiotic bacterial communities appear to contribute to scent pouch odors among wild Striped Hyenas. Here we characterize these bacterial communities among juvenile, young adult, and adult Hyenas. Akin to adult scent pouches, juvenile pouches are populated by fermentative bacteria from known odor-producing clades. However, the composition and structure of bacterial communities in juvenile scent pouches are different from, and more variable than, those of communities inhabiting the pouches of adults. Adult Striped Hyenas possess a core scent pouch bacterial community—12 bacterial types were shared among all sampled adults and consistently accounted for more than 90 % of the recovered 16S rRNA gene sequences. These bacterial types were less widespread and abundant among juveniles. Although verification will ultimately require longitudinal sampling of individual Hyenas throughout ontogeny, these data are consistent with the hypothesis that Striped Hyena scent pouch bacterial communities converge on a stereotypical phenotype during host development. We discuss how this could be facilitated by transmission of bacterial community members from adult scent pouches to those of juveniles by juveniles and adults occupying the same spaces, coming into recurrent physical contact, and/or scent overmarking each other.
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There and Back Again: Gene-Processing Hardware for the Evolution and Robotic Deployment of Robust Navigation Strategies
2015Co-Authors: David M. Bryson, Aaron P Wagner, Charles OfriaAbstract:Navigation strategies represent some of the most intriguing examples of complex and intelligent behaviors in nature. Accordingly, they have been the focus of extensive research in animal behavior and in evolutionary robotics. However, engineering successes in harnessing the evolutionary dynamics that shape sophisticated navigation strategies remain limited. Here we describe a novel gene-processing architecture for digital organisms that enables the evolution of central-place-foraging strategies, such as those seen in honeybees and Striped Hyena. While previous studies have evolved navigation de novo, the resulting algorithms have been relatively fragile and difficult to translate into physical systems. In contrast, the strategies evolved in this study are highly congruous with those seen in nature: a single evolved foraging strategy incorporates periods of directed travel, fixed pattern search, cue response, and reorientation when outcomes do not match expected results. Additionally, the genetic architecture enabled rapid extraction of the underlying behavioral algorithm and transference to a robotic system, proving to be robust to issues of noise and scale that commonly plague such attempts. Accordingly, we demonstrate that the flexibility and interpretability of the new gene-processing hardware readily facilitate the creation, study, and utilization of naturalistic and deployable algorithms for functionally complex behaviors
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GECCO - There and back again: gene-processing hardware for the evolution and robotic deployment of robust navigation strategies
Proceedings of the 2014 Annual Conference on Genetic and Evolutionary Computation, 2014Co-Authors: David M. Bryson, Aaron P Wagner, Charles OfriaAbstract:Navigation strategies represent some of the most intriguing examples of complex and intelligent behaviors in nature. Accordingly, they have been the focus of extensive research in animal behavior and in evolutionary robotics. However, engineering successes in harnessing the evolutionary dynamics that shape sophisticated navigation strategies remain limited. Here we describe a novel gene-processing architecture for digital organisms that enables the evolution of central-place-foraging strategies, such as those seen in honeybees and Striped Hyena. While previous studies have evolved navigation de novo, the resulting algorithms have been relatively fragile and difficult to translate into physical systems. In contrast, the strategies evolved in this study are highly congruous with those seen in nature: a single evolved foraging strategy incorporates periods of directed travel, fixed pattern search, cue response, and reorientation when outcomes do not match expected results. Additionally, the genetic architecture enabled rapid extraction of the underlying behavioral algorithm and transference to a robotic system, proving to be robust to issues of noise and scale that commonly plague such attempts. Accordingly, we demonstrate that the flexibility and interpretability of the new gene-processing hardware readily facilitate the creation, study, and utilization of naturalistic and deployable algorithms for functionally complex behaviors.
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phylogenetic comparisons implicate sex hormone binding globulin in masculinization of the female spotted Hyena crocuta crocuta
Endocrinology, 2012Co-Authors: Geoffrey L Hammond, Aaron P Wagner, Solange Miguelqueralt, T M Yalcinkaya, Caroline Underhill, Ned J Place, Stephen E Glickman, Christine M Drea, Pentti K SiiteriAbstract:Exposures to sex steroids during fetal development are thought to contribute to the unique urogenital anatomy and social dominance of the female spotted Hyena: overt phenotypes not shared by other hyenids (i.e. Striped Hyena, brown Hyena, and aardwolf). Because both androgens and estrogens influence development of genitalia and behavior, and because plasma SHBG regulates their access to tissues, we compared the Shbg gene sequences, structures, and steroid-binding properties in the four extant hyenids. We found the hyenid Shbg genes (>95% identical) and mature protein sequences (98% identical) are highly conserved. As in other mammals, the hyenid SHBG all bind 5α-dihydrotestosterone with high affinity (Kd = 0.62–1.47 nm), but they also bind estrone and dehydroepiandrosterone with similarly high affinity, and this unusual property was attributed to specific amino acids within their SHBG steroid-binding sites. Phylogenetic comparisons also indicated that the spotted Hyena SHBG precursor uniquely lacks two le...
Pentti K Siiteri - One of the best experts on this subject based on the ideXlab platform.
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phylogenetic comparisons implicate sex hormone binding globulin in masculinization of the female spotted Hyena crocuta crocuta
Endocrinology, 2012Co-Authors: Geoffrey L Hammond, Aaron P Wagner, Solange Miguelqueralt, T M Yalcinkaya, Caroline Underhill, Ned J Place, Stephen E Glickman, Christine M Drea, Pentti K SiiteriAbstract:Exposures to sex steroids during fetal development are thought to contribute to the unique urogenital anatomy and social dominance of the female spotted Hyena: overt phenotypes not shared by other hyenids (i.e. Striped Hyena, brown Hyena, and aardwolf). Because both androgens and estrogens influence development of genitalia and behavior, and because plasma SHBG regulates their access to tissues, we compared the Shbg gene sequences, structures, and steroid-binding properties in the four extant hyenids. We found the hyenid Shbg genes (>95% identical) and mature protein sequences (98% identical) are highly conserved. As in other mammals, the hyenid SHBG all bind 5α-dihydrotestosterone with high affinity (Kd = 0.62–1.47 nm), but they also bind estrone and dehydroepiandrosterone with similarly high affinity, and this unusual property was attributed to specific amino acids within their SHBG steroid-binding sites. Phylogenetic comparisons also indicated that the spotted Hyena SHBG precursor uniquely lacks two le...
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phylogenetic comparisons implicate sex hormone binding globulin in masculinization of the female spotted Hyena crocuta crocuta
Endocrinology, 2012Co-Authors: Geoffrey L Hammond, Aaron P Wagner, Solange Miguelqueralt, T M Yalcinkaya, Caroline Underhill, Ned J Place, Stephen E Glickman, Christine M Drea, Pentti K SiiteriAbstract:Exposures to sex steroids during fetal development are thought to contribute to the unique urogenital anatomy and social dominance of the female spotted Hyena: overt phenotypes not shared by other hyenids (i.e. Striped Hyena, brown Hyena, and aardwolf). Because both androgens and estrogens influence development of genitalia and behavior, and because plasma SHBG regulates their access to tissues, we compared the Shbg gene sequences, structures, and steroid-binding properties in the four extant hyenids. We found the hyenid Shbg genes (>95% identical) and mature protein sequences (98% identical) are highly conserved. As in other mammals, the hyenid SHBG all bind 5α-dihydrotestosterone with high affinity (K(d) = 0.62-1.47 nm), but they also bind estrone and dehydroepiandrosterone with similarly high affinity, and this unusual property was attributed to specific amino acids within their SHBG steroid-binding sites. Phylogenetic comparisons also indicated that the spotted Hyena SHBG precursor uniquely lacks two leucine residues and has a L15W substitution within its secretion signal polypeptide, the reduced size and hydrophobicity of which markedly decreases the production of SHBG and may therefore explain why serum SHBG concentrations in male and female spotted Hyenas are approximately five times lower than in other hyenids. This is important because low plasma SHBG concentrations in spotted Hyenas will increase exposure to biologically active androgens and estrogen as well as to their precursors (dehydroepiandrosterone and estrone), which may contribute to the masculinized external genitalia of female spotted Hyenas and to female social dominance over males.
Geoffrey L Hammond - One of the best experts on this subject based on the ideXlab platform.
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phylogenetic comparisons implicate sex hormone binding globulin in masculinization of the female spotted Hyena crocuta crocuta
Endocrinology, 2012Co-Authors: Geoffrey L Hammond, Aaron P Wagner, Solange Miguelqueralt, T M Yalcinkaya, Caroline Underhill, Ned J Place, Stephen E Glickman, Christine M Drea, Pentti K SiiteriAbstract:Exposures to sex steroids during fetal development are thought to contribute to the unique urogenital anatomy and social dominance of the female spotted Hyena: overt phenotypes not shared by other hyenids (i.e. Striped Hyena, brown Hyena, and aardwolf). Because both androgens and estrogens influence development of genitalia and behavior, and because plasma SHBG regulates their access to tissues, we compared the Shbg gene sequences, structures, and steroid-binding properties in the four extant hyenids. We found the hyenid Shbg genes (>95% identical) and mature protein sequences (98% identical) are highly conserved. As in other mammals, the hyenid SHBG all bind 5α-dihydrotestosterone with high affinity (Kd = 0.62–1.47 nm), but they also bind estrone and dehydroepiandrosterone with similarly high affinity, and this unusual property was attributed to specific amino acids within their SHBG steroid-binding sites. Phylogenetic comparisons also indicated that the spotted Hyena SHBG precursor uniquely lacks two le...
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phylogenetic comparisons implicate sex hormone binding globulin in masculinization of the female spotted Hyena crocuta crocuta
Endocrinology, 2012Co-Authors: Geoffrey L Hammond, Aaron P Wagner, Solange Miguelqueralt, T M Yalcinkaya, Caroline Underhill, Ned J Place, Stephen E Glickman, Christine M Drea, Pentti K SiiteriAbstract:Exposures to sex steroids during fetal development are thought to contribute to the unique urogenital anatomy and social dominance of the female spotted Hyena: overt phenotypes not shared by other hyenids (i.e. Striped Hyena, brown Hyena, and aardwolf). Because both androgens and estrogens influence development of genitalia and behavior, and because plasma SHBG regulates their access to tissues, we compared the Shbg gene sequences, structures, and steroid-binding properties in the four extant hyenids. We found the hyenid Shbg genes (>95% identical) and mature protein sequences (98% identical) are highly conserved. As in other mammals, the hyenid SHBG all bind 5α-dihydrotestosterone with high affinity (K(d) = 0.62-1.47 nm), but they also bind estrone and dehydroepiandrosterone with similarly high affinity, and this unusual property was attributed to specific amino acids within their SHBG steroid-binding sites. Phylogenetic comparisons also indicated that the spotted Hyena SHBG precursor uniquely lacks two leucine residues and has a L15W substitution within its secretion signal polypeptide, the reduced size and hydrophobicity of which markedly decreases the production of SHBG and may therefore explain why serum SHBG concentrations in male and female spotted Hyenas are approximately five times lower than in other hyenids. This is important because low plasma SHBG concentrations in spotted Hyenas will increase exposure to biologically active androgens and estrogen as well as to their precursors (dehydroepiandrosterone and estrone), which may contribute to the masculinized external genitalia of female spotted Hyenas and to female social dominance over males.
Pranay Amruth Maroju - One of the best experts on this subject based on the ideXlab platform.
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Schrodinger’s scat: a critical review of the currently available tiger (Panthera Tigris) and leopard (Panthera pardus) specific primers in India, and a novel leopard specific primer
BMC Genetics, 2016Co-Authors: Pranay Amruth Maroju, Qamar Qureshi, Sonu Yadav, Vishnupriya Kolipakam, Shweta Singh, Yadvendradev JhalaAbstract:Background Non-invasive sampling has opened avenues for the genetic study of elusive species, which has contributed significantly to their conservation. Where field based identity of non-invasive sample is ambiguous (e.g. carnivore scats), it is essential to establish identity of the species through molecular approaches. A cost effective procedure to ascertain species identity is to use species specific primers (SSP) for PCR amplification and subsequent resolution through agarose gel electrophoresis. However, SSPs if ill designed can often cross amplify non-target sympatric species. Herein we report the problem of cross amplification with currently published SSPs, which have been used in several recent scientific articles on tigers ( Panthera tigris) and leopards ( Panthera pardus ) in India. Since these papers form pioneering research on which future work will be based, an early rectification is required so as to not propagate this error further. Results We conclusively show cross amplification of three of the four SSPs, in sympatric non-target species like tiger SSP amplifying leopard and Striped Hyena ( Hyaena hyaena ), and leopard SSP amplifying tiger, lion ( Panthera leo persica ) and clouded leopard ( Neofelis nebulosa ), with the same product size. We develop and test a non-cross-amplifying leopard specific primer pair within the mitochondrial cytochrome b region. We also standardize a duplex PCR method to screen tiger and leopard samples simultaneously in one PCR reaction to reduce cost and time. Conclusions These findings suggest the importance of an often overlooked preliminary protocol of conclusive identification of species from non-invasive samples. The cross amplification of published primers in conspecifics suggests the need to revisit inferences drawn by earlier work.
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Schrodinger's scat: a critical review of the currently available tiger (Panthera Tigris) and leopard (Panthera pardus) specific primers in India, and a novel leopard specific primer.
BMC genetics, 2016Co-Authors: Pranay Amruth Maroju, Qamar Qureshi, Sonu Yadav, Vishnupriya Kolipakam, Shweta Singh, Yadvendradev V. JhalaAbstract:Non-invasive sampling has opened avenues for the genetic study of elusive species, which has contributed significantly to their conservation. Where field based identity of non-invasive sample is ambiguous (e.g. carnivore scats), it is essential to establish identity of the species through molecular approaches. A cost effective procedure to ascertain species identity is to use species specific primers (SSP) for PCR amplification and subsequent resolution through agarose gel electrophoresis. However, SSPs if ill designed can often cross amplify non-target sympatric species. Herein we report the problem of cross amplification with currently published SSPs, which have been used in several recent scientific articles on tigers (Panthera tigris) and leopards (Panthera pardus) in India. Since these papers form pioneering research on which future work will be based, an early rectification is required so as to not propagate this error further. We conclusively show cross amplification of three of the four SSPs, in sympatric non-target species like tiger SSP amplifying leopard and Striped Hyena (Hyaena hyaena), and leopard SSP amplifying tiger, lion (Panthera leo persica) and clouded leopard (Neofelis nebulosa), with the same product size. We develop and test a non-cross-amplifying leopard specific primer pair within the mitochondrial cytochrome b region. We also standardize a duplex PCR method to screen tiger and leopard samples simultaneously in one PCR reaction to reduce cost and time. These findings suggest the importance of an often overlooked preliminary protocol of conclusive identification of species from non-invasive samples. The cross amplification of published primers in conspecifics suggests the need to revisit inferences drawn by earlier work.
Qamar Qureshi - One of the best experts on this subject based on the ideXlab platform.
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Schrodinger’s scat: a critical review of the currently available tiger (Panthera Tigris) and leopard (Panthera pardus) specific primers in India, and a novel leopard specific primer
BMC Genetics, 2016Co-Authors: Pranay Amruth Maroju, Qamar Qureshi, Sonu Yadav, Vishnupriya Kolipakam, Shweta Singh, Yadvendradev JhalaAbstract:Background Non-invasive sampling has opened avenues for the genetic study of elusive species, which has contributed significantly to their conservation. Where field based identity of non-invasive sample is ambiguous (e.g. carnivore scats), it is essential to establish identity of the species through molecular approaches. A cost effective procedure to ascertain species identity is to use species specific primers (SSP) for PCR amplification and subsequent resolution through agarose gel electrophoresis. However, SSPs if ill designed can often cross amplify non-target sympatric species. Herein we report the problem of cross amplification with currently published SSPs, which have been used in several recent scientific articles on tigers ( Panthera tigris) and leopards ( Panthera pardus ) in India. Since these papers form pioneering research on which future work will be based, an early rectification is required so as to not propagate this error further. Results We conclusively show cross amplification of three of the four SSPs, in sympatric non-target species like tiger SSP amplifying leopard and Striped Hyena ( Hyaena hyaena ), and leopard SSP amplifying tiger, lion ( Panthera leo persica ) and clouded leopard ( Neofelis nebulosa ), with the same product size. We develop and test a non-cross-amplifying leopard specific primer pair within the mitochondrial cytochrome b region. We also standardize a duplex PCR method to screen tiger and leopard samples simultaneously in one PCR reaction to reduce cost and time. Conclusions These findings suggest the importance of an often overlooked preliminary protocol of conclusive identification of species from non-invasive samples. The cross amplification of published primers in conspecifics suggests the need to revisit inferences drawn by earlier work.
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Schrodinger's scat: a critical review of the currently available tiger (Panthera Tigris) and leopard (Panthera pardus) specific primers in India, and a novel leopard specific primer.
BMC genetics, 2016Co-Authors: Pranay Amruth Maroju, Qamar Qureshi, Sonu Yadav, Vishnupriya Kolipakam, Shweta Singh, Yadvendradev V. JhalaAbstract:Non-invasive sampling has opened avenues for the genetic study of elusive species, which has contributed significantly to their conservation. Where field based identity of non-invasive sample is ambiguous (e.g. carnivore scats), it is essential to establish identity of the species through molecular approaches. A cost effective procedure to ascertain species identity is to use species specific primers (SSP) for PCR amplification and subsequent resolution through agarose gel electrophoresis. However, SSPs if ill designed can often cross amplify non-target sympatric species. Herein we report the problem of cross amplification with currently published SSPs, which have been used in several recent scientific articles on tigers (Panthera tigris) and leopards (Panthera pardus) in India. Since these papers form pioneering research on which future work will be based, an early rectification is required so as to not propagate this error further. We conclusively show cross amplification of three of the four SSPs, in sympatric non-target species like tiger SSP amplifying leopard and Striped Hyena (Hyaena hyaena), and leopard SSP amplifying tiger, lion (Panthera leo persica) and clouded leopard (Neofelis nebulosa), with the same product size. We develop and test a non-cross-amplifying leopard specific primer pair within the mitochondrial cytochrome b region. We also standardize a duplex PCR method to screen tiger and leopard samples simultaneously in one PCR reaction to reduce cost and time. These findings suggest the importance of an often overlooked preliminary protocol of conclusive identification of species from non-invasive samples. The cross amplification of published primers in conspecifics suggests the need to revisit inferences drawn by earlier work.
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Population density of Striped Hyenas in relation to habitat in a semi-arid landscape, western India
Acta Theriologica, 2014Co-Authors: Randeep Singh, Kalyanasundaram Sankar, Qamar Qureshi, Surendra Prakash Goyal, Paul R. Krausman, Kerry L. NicholsonAbstract:We used camera trapping in conjunction with a spatial explicit capture–recapture model to estimate Striped Hyena (Hyaena hyaena) density and occupancy models to investigate factors affecting Striped Hyena detection probabilities in Ranthambhore Tiger Reserve (RTR), Rajasthan, India. A sampling effort of 4,450 trap days/nights over 75 days yield 68 photo captures of 21 unique Striped Hyenas (based on individual markings and visual identification); the estimated Striped Hyena density was 5.49 ± 1.27 individuals/100 km2. Results of our occupancy model suggested that a rugged terrain is an important factor that influences Striped Hyena detection probability. Correlation with Striped Hyena detection with human settlement provides evidence of social tolerance of Striped Hyena towards humans, and more occurrence of resources allowed coexistence of Hyena in a human-dominated landscape. This elasticity (inhabited areas close to humans) demonstrated by Striped Hyenas is an exception among carnivore communities living in this semi-arid habitat.
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food habits of golden jackal canis aureus and Striped Hyena hyaena hyaena in sariska tiger reserve western india
2012Co-Authors: Pooja Chourasia, Krishnendu Mondal, Kalyanasundaram Sankar, Qamar QureshiAbstract:Food habits of golden jackal (Canis aureus) and Striped Hyena (Hyaena hyaena) were investigated using scat analysis between November 2010 and June 2011 in Sariska Tiger Reserve, Western India. Total 104 scats of golden jackal and 86 scats of Striped Hyena were collected and analyzed. The frequency of occurrence of each prey species was estimated through bootstrapping using program SIMSTAT. Niche breadth of these two species was quantified using Levin's measure. The diet overlap in the two species was assessed using Pianka's index. Twelve food items were identified in golden jackal scats and nine in Striped Hyena scats. Vegetative matter contributed maximum (17.57%) in jackal's diet followed by rodents (15.77%), chital (10.81%), sambar (5.41%) and nilgai (4.05%). Nilgai and domestic cattle contributed maximum (24.76% each) in the diet of Striped Hyena, followed by sambar (17.14%), chital (16.19%) and vegetative matter (10.48%). The estimated dietary overlap between Striped Hyena and golden jackal was 67%. Niche breadth for golden jackal was estimated as 0.69 and for Striped Hyena it was 0.57. The considerable overlap was attributed to mutual dependence on ungulates, which indicated high resource competition between the two species.
