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Kay E Holekamp - One of the best experts on this subject based on the ideXlab platform.
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Pastoralist activities affect the movement patterns of a large African carnivore, the spotted hyena (crocuta crocuta)
Journal of Mammalogy, 2019Co-Authors: David Green, Kay E HolekampAbstract:Abstract Populations of large carnivores are declining in many parts of the world due to anthropogenic activity. Some species of large carnivores, however, are able to coexist with people by altering their behavior. Altered behaviors may be challenging to identify in large carnivores because these animals are typically cryptic, nocturnal, live at low densities, and because changes in their behavior may be subtle or emerge slowly over many years. We studied the effects of livestock presence on the movements of one large carnivore, the spotted hyena (crocuta crocuta). We fit 22 adult female spotted hyenas with GPS collars to quantify their movements in areas with and without livestock or herders present, in and around a protected area in southwestern Kenya. We investigated anthropogenic, social, and ecological effects on the speed of movement, distances traveled, long-distance movements, and extraterritorial excursions by spotted hyenas. Hyenas living primarily within the protected area, but in the presence of livestock and herders, moved faster, traveled over longer distances, and were more likely to be within their territories than did conspecifics living in areas without livestock and herders. Hyenas of low social rank were more likely than hyenas of high social rank to engage in long-distance travel events, and these were more likely to occur when prey were scarce. The movement patterns of this large African carnivore indicate a flexibility that may allow them to persist in landscapes that are becoming increasingly defined by people.
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ontogeny of sexual size dimorphism in the spotted hyena crocuta crocuta
Journal of Mammalogy, 2013Co-Authors: Eli M Swanson, Mary L. Weldele, Stephen E. Glickman, Teresa L Mcelhinny, Ian Dworkin, Kay E HolekampAbstract:Body size and growth rate are among the most important traits characterizing an organism, influencing niche occupancy, life-history patterns, mortality rates, and many other fitness components. Sexual size dimorphism is common among animals; in most species females are on average larger than males. In contrast, male mammals are usually larger on average than females of the same species, and the spotted hyena (crocuta crocuta) may be one of the rare species of mammal in which females are generally larger than males. Nevertheless, some have argued that the evidence is equivocal regarding this reversal. This disagreement may reflect differences in traits measured, methods used, or ontogenetic differences among individuals sampled for these studies. We quantified size at various points during ontogeny in 651 individuals, the largest sample used in size analyses of spotted hyenas to date. We measured 14 morphological traits as well as 4 linear combinations of the traits that provide multivariate estimates of size; these were used to examine growth patterns among males and females measured in a free-living population in Kenya. We demonstrate that female spotted hyenas are larger than males for most, but not all traits, and that females are larger because they grow faster, rather than exhibiting a prolonged period of growth. Early in life males and females appear to grow similarly, but between weaning and reproductive maturity their multivariate ontogenetic trajectories diverge. Traits that mature before divergence of these ontogenetic trajectories are monomorphic, whereas traits that mature later are dimorphic. Furthermore, dimorphism is generally greatest in traits that cease development latest. We propose that later-maturing traits are more dimorphic because of a systemic increase in female growth rates during adolescence that persists through morphological maturity, which varies among traits. We also assess body-size data obtained from captive hyenas to show that adult female hyenas are larger than adult males for some traits even when they are fed identical diets throughout development, allowing us to rule out a strictly environmental explanation for this dimorphism.
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complete genome sequence of the crocuta crocuta papillomavirus type 1 ccrpv1 from a spotted hyena the first papillomavirus characterized in a member of the hyaenidae
Genome Announcements, 2013Co-Authors: Hans Stevens, Kay E Holekamp, Anne L. Engh, Keith G. Nelson, Elisabeth Heylen, Karlien De Keyser, Roger K Maes, Matti Kiupel, Annabel G Wise, Christy A McknightAbstract:ABSTRACT We report the complete genomic sequence of the crocuta crocuta papillomavirus type 1 (CcrPV1), isolated from an oral papillomatous lesion of a wild spotted hyena. This virus is the first papillomavirus found in a species belonging to the Hyaenidae family of carnivores, and it can be classified in the genus Lambdapapillomavirus .
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Numerical assessment and individual call discrimination by wild spotted hyaenas, crocuta crocuta
Animal Behaviour, 2011Co-Authors: Sarah Benson-amram, Virginia K. Heinen, Sean L. Dryer, Kay E HolekampAbstract:Game theory predicts that individuals should assess numbers of potential opponents before engaging in aggressive interactions, particularly when numerical odds can determine outcomes of such interactions. Spotted hyaenas, crocuta crocuta ,l ive infissionefusion societies in which extreme numerical imbalances can occur during intergroup conflicts, which are potentially lethal. Thus, an ability to assess relative numbers of opponents should be highly advantageous in this species. Here we tested abilities of wild spotted hyaenas to assess numerical advantage with a playback experiment by presenting contact calls produced by one, two or three unknown hyaenas, or ‘intruders’, to individuals in our study clans. Hyaenas conformed to predictions of game theory by increasing vigilance to playbacks of multiple unfamiliar intruders. Furthermore, hyaenas distinguished not just between calls produced by one versus multiple intruders, but showed a fine-grained ability to assess numerical advantage, and they responded with increasing levels of vigilance to calls produced by one, two and three unknown intruders. Hyaenas also took more risks by approaching the speaker when they outnumbered calling intruders. Lastly, this study provides experimental evidence that spotted hyaenas can use contact calls to distinguish among individuals.
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Provisioning and Food Sharing by Lactating Spotted Hyenas, crocuta crocuta (Mammalia: Hyaenidae)
Ethology, 2010Co-Authors: Kay E Holekamp, Laura SmaleAbstract:In contrast to most other carnivores, spotted hyenas (crocuta crocuta) do not regularly carry food back to their dens for provisioning of dependent young. Kruuk (1976) and Mills (1989) hypothesized that high levels of competition for provisioned food at the communal dens utilized by spotted hyenas may have selected against provisioning behavior in this species. We observed lactating female spotted hyenas carry food from ungulate kills to their dependent cubs at the den 18 times, and share food with their dependent cubs at kills 33 times. We used these data to test the Kruuk/Mills hypothesis by assessing effects of feeding competition on provisioning behavior. Provisioning rates were low, and were correlated with social rank. Provisioning attempts were often unsuccessful. Females dominant to the provisioner, with cubs also residing at the communal den, were the most effective competitors for provisioned food. Attempts to share food with cubs at kills were more successful than were attempts to provision cubs at the den. Our data thus support the Kruuk/Mills hypothesis.
Stephen E. Glickman - One of the best experts on this subject based on the ideXlab platform.
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Brain and Body Size Relations among Spotted Hyenas (crocuta crocuta).
Brain behavior and evolution, 2018Co-Authors: Michael D. Mann, Lawrence G. Frank, Stephen E. Glickman, Arnold L. ToweAbstract:The relationship between brain size and body size across species "from mouse to elephant" is described by a function of positive slope. Almost uniformly, the relationship between brain size and body size within a species has a positive slope, though this is less steep than across species. The spotted hyena, crocuta crocuta, differs from most other mammals in a number of ways including the fact that, on average, adult females weigh more than adult males and occasionally display greater body lengths. Brains of 5 female and 4 male hyenas were weighed in the field near Moyale in Northern Kenya, and body weights and body lengths were obtained from the same animals. When our analyses of brain/body relationships in these animals revealed an unanticipated negative relationship between brain size and body length, we extended our measurements to include intracranial volume in 19 skulls (8 females and 11 males) from the collection at the Museum of Vertebrate Zoology, University of California Berkeley; body weights and lengths were also available. A third dataset was formed by measuring intracranial volumes in 60 spotted hyena skulls (27 females and 33 males) in the Natural History Museum, London, UK; body lengths and intracranial volumes were available. Brain/body size slopes, in general, were not significantly different from zero except in 3 cases: brain weight/body length for Moyale males alone and males and females together, and cranial volume/body weight for Museum of Vertebrate Zoology males and females together. Although most of the slopes were not significantly different from zero, they were all negative, and a statistical test which combined probabilities from the 3 datasets supports the conclusion that there is a negative relationship between brain size and body size in spotted hyenas. Possible explanations for the negative slopes are discussed, including costs and benefits of large brains and large bodies and physiological mechanisms.
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ontogeny of sexual size dimorphism in the spotted hyena crocuta crocuta
Journal of Mammalogy, 2013Co-Authors: Eli M Swanson, Mary L. Weldele, Stephen E. Glickman, Teresa L Mcelhinny, Ian Dworkin, Kay E HolekampAbstract:Body size and growth rate are among the most important traits characterizing an organism, influencing niche occupancy, life-history patterns, mortality rates, and many other fitness components. Sexual size dimorphism is common among animals; in most species females are on average larger than males. In contrast, male mammals are usually larger on average than females of the same species, and the spotted hyena (crocuta crocuta) may be one of the rare species of mammal in which females are generally larger than males. Nevertheless, some have argued that the evidence is equivocal regarding this reversal. This disagreement may reflect differences in traits measured, methods used, or ontogenetic differences among individuals sampled for these studies. We quantified size at various points during ontogeny in 651 individuals, the largest sample used in size analyses of spotted hyenas to date. We measured 14 morphological traits as well as 4 linear combinations of the traits that provide multivariate estimates of size; these were used to examine growth patterns among males and females measured in a free-living population in Kenya. We demonstrate that female spotted hyenas are larger than males for most, but not all traits, and that females are larger because they grow faster, rather than exhibiting a prolonged period of growth. Early in life males and females appear to grow similarly, but between weaning and reproductive maturity their multivariate ontogenetic trajectories diverge. Traits that mature before divergence of these ontogenetic trajectories are monomorphic, whereas traits that mature later are dimorphic. Furthermore, dimorphism is generally greatest in traits that cease development latest. We propose that later-maturing traits are more dimorphic because of a systemic increase in female growth rates during adolescence that persists through morphological maturity, which varies among traits. We also assess body-size data obtained from captive hyenas to show that adult female hyenas are larger than adult males for some traits even when they are fed identical diets throughout development, allowing us to rule out a strictly environmental explanation for this dimorphism.
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what the hyena s laugh tells sex age dominance and individual signature in the giggling call of crocuta crocuta
BMC Ecology, 2010Co-Authors: Stephen E. Glickman, Mary L. Weldele, Nicolas Mathevon, Aaron Koralek, Frédéric E. TheunissenAbstract:Background Among mammals living in social groups, individuals form communication networks where they signal their identity and social status, facilitating social interaction. In spite of its importance for understanding of mammalian societies, the coding of individual-related information in the vocal signals of non-primate mammals has been relatively neglected. The present study focuses on the spotted hyena crocuta crocuta, a social carnivore known for its complex female-dominated society. We investigate if and how the well-known hyena's laugh, also known as the giggle call, encodes information about the emitter.
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What the hyena's laugh tells : sex, age, dominance and individual signature in the giggling call of crocuta crocuta.
BMC Ecology, 2010Co-Authors: Nicolas Mathevon, Stephen E. Glickman, Aaron Koralek, Mary Weldele, Frédéric E. TheunissenAbstract:Background Among mammals living in social groups, individuals form communication networks where they signal their identity and social status, facilitating social interaction. In spite of its importance for understanding of mammalian societies, the coding of individual-related information in the vocal signals of non-primate mammals has been relatively neglected. The present study focuses on the spotted hyena crocuta crocuta, a social carnivore known for its complex female-dominated society. We investigate if and how the well-known hyena's laugh, also known as the giggle call, encodes information about the emitter. Results By analyzing acoustic structure in both temporal and frequency domains, we show that the hyena's laugh can encode information about age, individual identity and dominant/subordinate status, providing cues to receivers that could enable assessment of the social position of an emitting individual. Conclusions The range of messages encoded in the hyena's laugh is likely to play a role during social interactions. This call, together with other vocalizations and other sensory channels, should ensure an array of communication signals that support the complex social system of the spotted hyena. Experimental studies are now needed to decipher precisely the communication network of this species.
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placental expression and molecular characterization of aromatase cytochrome p450 in the spotted hyena crocuta crocuta
Placenta, 2007Co-Authors: Alan J Conley, C J Corbin, Patience Browne, Samantha Mapes, Austin L Hughes, Ned J Place, Stephen E. GlickmanAbstract:At birth, the external genitalia of female spotted hyenas (crocuta crocuta) are the most masculinized of any known mammal, but are still sexually differentiated. Placental aromatase cytochrome P450 (P450arom) is an important route of androgen metabolism protecting human female fetuses from virilization in utero. Therefore, placental P450arom expression was examined in spotted hyenas to determine levels during genital differentiation, and to compare molecular characteristics between the hyena and human placental enzymes. Hyena placental P450arom activity was determined at gestational days (GD) 31, 35, 45, 65 and 95 (term, 110), and the relative sensitivity of hyena and human placental enzyme to inhibition by the specific inhibitor, Letrozole, was also examined. Expression of hyena P450arom in placenta was localized by immuno-histochemistry, and a full-length cDNA was cloned for phylogenetic analysis. Aromatase activity increased from GD31 to a peak at 45 and 65, apparently decreasing later in gestation. This activity was more sensitive to inhibition by Letrozole than was human placental aromatase activity. Expression of P450arom was localized to syncytiotrophoblast and giant cells of mid-gestation placentas. The coding sequence of hyena P450arom was 94% and 86% identical to the canine and human enzymes respectively, as reflected by phylogenetic analyses. These data demonstrate for the first time that hyena placental aromatase activity is comparable to that of human placentas when genital differentiation is in progress. This suggests that even in female spotted hyenas clitoral differentiation is likely protected from virilization by placental androgen metabolism. Decreased placental aromatase activity in late gestation may be equally important in allowing androgen to program behaviors at birth. Although hyena P450arom is closely related to the canine enzyme, both placental anatomy and P450arom expression differ. Other hyaenids and carnivores must be investigated to determine the morphological and functional ancestral state of their placentas, as it relates to evolutionary relationships among species in this important taxonomic group.
Hans Bauer - One of the best experts on this subject based on the ideXlab platform.
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spotted hyena crocuta crocuta concentrate around urban waste dumps across tigray northern ethiopia
Wildlife Research, 2015Co-Authors: Gidey Yirga, Hans H De Iongh, Tsehaye Asmelash, Herwig Leirs, Kindeya Gebrehiwot, Jozef Deckers, Hans BauerAbstract:Context. The spotted hyena (crocuta crocuta) lives in remarkably close proximity to humans in the degraded and prey-depleted landscapes in Tigray in northern Ethiopia, predominantly feeding on human organic waste.Aims. We sought to provide an estimate of spotted hyena abundance at garbage dumps and open agricultural areas across Tigray.Methods. We used 28 calling stations, including 12 at garbage dumps and 16 in open agricultural areas located in nine randomly selected urban districts across Tigray. We also used 65 randomly placed calling stations in three districts to establish spotted hyena abundance in Tigray. We also collected 610 scat samples during wet (n = 134) and dry season (n = 476) so as to identify diet.Key results. A total of 398 hyenas responded, including 356 hyenas at garbage dumps and 42 hyenas in open agricultural areas. The response at the garbage dumps was significantly higher. Approximately 2525 hyenas were estimated from 65 calling stations in three districts. There was no statistically significant difference in the diet of hyena between wet and dry seasons for any food item. Frequency occurrence of prey remains of donkeys and cattle were dominant, followed by human, goat and sheep, respectively.Key conclusions. We infer that a very large hyena population persists in unprotected areas of Tigray in northern Ethiopia, where they concentrate around urban waste dumps at night for scavengeable food resources, mainly originating from slaughterhouse waste of livestock.Implications. We suggest promotion of nature-based ecotourism of this exceptional coexistence of hyenas and humans in Ethiopia. We raise questions about local hyena social structure, movement, home-range, activity pattern and the implications for human–hyena coexistence.
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food base of the spotted hyena crocuta crocuta in ethiopia
Wildlife Research, 2015Co-Authors: Gidey Yirga, Hans H De Iongh, Herwig Leirs, Kindeya Gebrehiwot, Jozef Deckers, Hans BauerAbstract:Abstract Context. Livestock depredation and scavenging of waste by the spotted hyena (crocuta crocuta) occurs widely across Ethiopia. Aims. The aim of this study was to investigate the food base of the spotted hyena and livestock depredation across Ethiopia. Methods. The diet of spotted hyenas was assessed in 17 randomly selected study sites across the country, including two national parks, by scat analysis. We conducted an extensive survey of livestock depredation and economic impact in 10 randomly selected subdistricts using semistructured interviews with 3080 randomly selected households. Key results. We found that even spotted hyenas from national parks feed predominantly on anthropogenic waste. Households reported losses of 2230 domestic animals, 3.9% of their stock or an average annual financial loss of US$10.3 per household over the past five years. The diet of spotted hyenas showed only prey items of domestic origin except in Chebera Churchura National Park, where a few items of prey of wild speci...
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Status of Lion (Panthera leo) and Spotted Hyena (crocuta crocuta) in Nechisar National Park, Ethiopia
Momona Ethiopian Journal of Science, 2014Co-Authors: Gidey Yirga, Fikirte Gebresenbet, Jozef Deckers, Hans BauerAbstract:Globally large carnivores are in decline due to a combination of habitat degradation and direct human persecution. A survey was conducted in Nechisar national park, Southern Ethiopia to investigate the population status of lion ( Panthera leo ) and hyena ( crocuta crocuta ). Eleven callups were performed; a total of two adult male lions and six spotted hyenas responded. Estimates give a lion density of between 2 and 5 per 100 km 2 or a total population estimate of 7 to 23 lions and a hyena density of between 4 to 8 hyenas per 100 km 2 or a total population estimate of 17 to 34 hyenas. These estimates include extrapolation to a heavily encroached area where large carnivores are unlikely to occur. The lion population is probably limited to the visually confirmed four individuals. The carrying capacity of Nechisar national park, excluding livestock, is 21 lions and 48 hyenas. The resident agro-pastoral communities who are living with their livestock inside and adjacent to the national park are in conflict with carnivores. This might account for the low density of lion and hyena in the park, and perhaps might result in local extinction within a few years. Keywords : Callups, Hyena, Lion, Nechisar, Density, Ethiopia.
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spotted hyena crocuta crocuta coexisting at high density with people in wukro district northern ethiopia
Mammalian Biology, 2013Co-Authors: Gidey Yirga, Wondimu Ersino, Hans H De Iongh, Herwig Leirs, Hans Bauer, Kindeya Gebrehiwot, Jozef DeckersAbstract:We surveyed density and abundance of spotted hyena (crocuta crocuta) in the highly degraded and prey depleted Wukro district, northern Ethiopia, with a human population density of 98 persons per square kilometer. A total of 117 spotted hyenas responded to callups, giving a hyena density of 52 hyenas per 100 km2 or a total population of 535 hyenas in the district. We quantified the economic impact of spotted hyena predation on livestock using semi structured interviews with randomly selected households. Respondents indicated a total loss of 203 domestic animals to hyena depredation over the past five years. Average annual depredation per household was 0.13 livestock worth US$ 6.1. The diet of spotted hyenas was assessed in three sub-districts by scat analysis and showed 99% prey items of domestic origin, only three of 211 scat contained hair of Ethiopian hare (Lepus fagani) and porcupine (Hystrix cristata). We conclude that hyenas in northern Ethiopia live at high density and eat almost exclusively anthropogenic food and are not dependent on conservation areas.
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adaptability of large carnivores to changing anthropogenic food sources diet change of spotted hyena crocuta crocuta during christian fasting period in northern ethiopia
Journal of Animal Ecology, 2012Co-Authors: Gidey Yirga, Hans H De Iongh, Kindeya Gebrihiwot, Herwig Leirs, Jozef Deckers, Hans BauerAbstract:Adaptability of large carnivores to changing anthropogenic food sources: diet change of spotted hyena (crocuta crocuta) during Christian fasting period in northern Ethiopia Gidey Yirga*, HansH. De Iongh, Herwig Leirs, KindeyaGebrihiwot, Jozef Deckers andHansBauer Department of Biology, Mekelle University, P.O. Box 3072, Mekelle, Ethiopia; Institute of Environmental Sciences, Leiden University, P.O. Box 9518, Leiden, TheNetherlands; Evolutionary EcologyGroup, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium; Department of Agro-Ecology, Aarhus University, Forsogsvej 1, 4200 Slagelse, Denmark; Department of LandResourceManagement and Environmental Protection, Mekelle University, P.O. Box 231,Mekelle, Ethiopia; and Department of Earth and Environmental Sciences, Catholic University of Leuven, Celestijnenlaan 200E, B-3001Heverlee, Belgium
M. G. L. Mills - One of the best experts on this subject based on the ideXlab platform.
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estimating the size of spotted hyaena crocuta crocuta populations through playback recordings allowing for non response
Animal Conservation, 2001Co-Authors: M. G. L. Mills, J. M. Juritz, W. ZucchiniAbstract:Conventional census techniques are inappropriate for estimating numbers of nocturnal animals such as the spotted hyaena (crocuta crocuta). A technique based on attracting animals by taped sounds to calling stations is described. A simple independent experiment to estimate the probability of response to the sounds, as well as a probability model for estimating the population size in a given habitat based on the response counts, is proposed. The model allows for the possibility that some animals may not respond to sounds. The estimate of the population size has a simple form and the sensitivity of the estimate to changes in the response probability can be assessed. The model allows statistical comparisons to be made between different habitats or different times. Likelihood-based confidence intervals can be found for all estimates. The results of surveys in the Kruger National Park illustrate the technique which can be applied in different areas and possibly to other species.
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Estimating the size of spotted hyaena (crocuta crocuta) populations through playback recordings allowing for non‐response
Animal Conservation, 2001Co-Authors: M. G. L. Mills, J. M. Juritz, W. ZucchiniAbstract:Conventional census techniques are inappropriate for estimating numbers of nocturnal animals such as the spotted hyaena (crocuta crocuta). A technique based on attracting animals by taped sounds to calling stations is described. A simple independent experiment to estimate the probability of response to the sounds, as well as a probability model for estimating the population size in a given habitat based on the response counts, is proposed. The model allows for the possibility that some animals may not respond to sounds. The estimate of the population size has a simple form and the sensitivity of the estimate to changes in the response probability can be assessed. The model allows statistical comparisons to be made between different habitats or different times. Likelihood-based confidence intervals can be found for all estimates. The results of surveys in the Kruger National Park illustrate the technique which can be applied in different areas and possibly to other species.
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Social systems and behaviour of the African wild dog Lycaon pictus and the spotted hyaena crocuta crocuta with special reference to rabies.
The Onderstepoort journal of veterinary research, 1993Co-Authors: M. G. L. MillsAbstract:MILLS, M.G.L. 1993. Social systems and behaviour of the African wild dog Lycaon pictus and the spot ted hyaena crocuta crocuta with special reference to rabies. Onderstepoort Journal of Veterinary Re search, 60:405-409 Differences in the social systems and behaviour of two potentially important hosts of rabies, the African wild dog and the spotted hyaena, may lead to differences in the epizootiology of the disease in the two species. Wild dogs are highly social animals in which pack members are in constant physical contact with each other, but in which inter-pack interactions are rare. Spotted hyaenas are more flexible in their social systems and behaviour. Clan members interact less frequently than do wild dogs, but inter-clan contact rates may be high in high density populations. Rabies transmission within wild dog packs should be rapid, but rare between packs. In spotted hyaenas rabies transmission between clan members may partially depend on the social status of the animals involved and between packs on the density of hyae nas in the area.
Frédéric E. Theunissen - One of the best experts on this subject based on the ideXlab platform.
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What the hyena's laugh tells : sex, age, dominance and individual signature in the giggling call of crocuta crocuta.
BMC Ecology, 2010Co-Authors: Nicolas Mathevon, Stephen E. Glickman, Aaron Koralek, Mary Weldele, Frédéric E. TheunissenAbstract:Background Among mammals living in social groups, individuals form communication networks where they signal their identity and social status, facilitating social interaction. In spite of its importance for understanding of mammalian societies, the coding of individual-related information in the vocal signals of non-primate mammals has been relatively neglected. The present study focuses on the spotted hyena crocuta crocuta, a social carnivore known for its complex female-dominated society. We investigate if and how the well-known hyena's laugh, also known as the giggle call, encodes information about the emitter. Results By analyzing acoustic structure in both temporal and frequency domains, we show that the hyena's laugh can encode information about age, individual identity and dominant/subordinate status, providing cues to receivers that could enable assessment of the social position of an emitting individual. Conclusions The range of messages encoded in the hyena's laugh is likely to play a role during social interactions. This call, together with other vocalizations and other sensory channels, should ensure an array of communication signals that support the complex social system of the spotted hyena. Experimental studies are now needed to decipher precisely the communication network of this species.
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what the hyena s laugh tells sex age dominance and individual signature in the giggling call of crocuta crocuta
BMC Ecology, 2010Co-Authors: Stephen E. Glickman, Mary L. Weldele, Nicolas Mathevon, Aaron Koralek, Frédéric E. TheunissenAbstract:Background Among mammals living in social groups, individuals form communication networks where they signal their identity and social status, facilitating social interaction. In spite of its importance for understanding of mammalian societies, the coding of individual-related information in the vocal signals of non-primate mammals has been relatively neglected. The present study focuses on the spotted hyena crocuta crocuta, a social carnivore known for its complex female-dominated society. We investigate if and how the well-known hyena's laugh, also known as the giggle call, encodes information about the emitter.
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Vocalizations of the Spotted Hyena (crocuta crocuta): Eliciting Acoustic Variation in Groans
Journal of the Acoustical Society of America, 2008Co-Authors: Frédéric E. Theunissen, Steve Glickman, Suzanne PageAbstract:Spotted hyenas (crocuta crocuta) are highly social animals possessing a complex vocal repertoire. Vocal signals of different types correlate with distinct social circumstances. Groans constitute a very large category in the spotted hyena repertoire which is not well understood. Sounds labeled as groans vary in their acoustical quality from more growling sounds to more tonal vocalizations. Groans are also elicited in many different social interactions. To begin to decipher the meaning of these vocal signals, we examined how the variation in the acoustic properties of groans was correlated with experimentally controlled eliciting conditions. Groans were elicited in adult hyenas presented with three objects: unfamiliar spotted hyena cubs, meaty bones, and the empty transport cage used to contain bones or cubs on other trials. Cubs elicited more groans from more adults than other objects but all objects elicited vocal responses. More importantly, discriminant analysis revealed differences in the acoustic characteristics of groans elicited by cubs and those elicited by other objects. Cubs elicited more prolonged and more tonal groans with higher fundamental frequency. Our study shows that groans can be classified into different groups and that these different sounds were produced in different behavioral contexts.