Journal ArticleFrontiers in Endocrinology · September 30, 2024
IntroductionMammalian reproductive and somatic development is regulated by steroid hormones, growth hormone (GH), and insulin-like growth factor-1 (IGF-1). Based largely on information from humans, model organisms ...
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Journal ArticleBiological reviews of the Cambridge Philosophical Society · April 2024
Microbiome science has provided groundbreaking insights into human and animal health. Similarly, evolutionary medicine - the incorporation of eco-evolutionary concepts into primarily human medical theory and practice - is increasingly recognised for its no ...
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Journal ArticlePsychoneuroendocrinology · April 2023
A prominent body of research spanning disciplines has been focused on the potential underlying role for oxytocin in the social signatures of monogamous mating bonds. Behavioral differences between monogamous and non-monogamous vole species, putatively medi ...
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Journal ArticleScientific reports · December 2022
Microbial rewilding, whereby exposure to naturalistic environments can modulate or augment gut microbiomes and improve host-microbe symbiosis, is being harnessed as an innovative approach to human health, one that may also have significant value to animal ...
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Chapter · November 29, 2022
Stephen E. Glickman (1933-2020) was an American comparative psychologist and scholar of the history of psychology, who contributed over 100 publications relevant to the study of animal behavior, cognitive and behavioral neuroscience, reproductive neuroendo ...
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Journal ArticleHormones and behavior · September 2022
This article is part of a Special Issue (Hormones and Hierarchies). To gain more balanced understanding of sexual selection and mammalian sexual differentiation processes, this review addresses behavioral sex differences and hormonal mediators of intrasexu ...
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Journal ArticleAnimal microbiome · April 2022
BackgroundInter-population variation in host-associated microbiota reflects differences in the hosts' environments, but this characterization is typically based on studies comparing few populations. The diversity of natural habitats and captivity ...
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Journal ArticleHormones and behavior · March 2022
In the decades since female social dominance was first described in strepsirrhine primates, researchers have sought to uncover the proximate and ultimate explanations for its development. In the females of various female-dominant species, androgens have be ...
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Journal ArticleInternational Journal of Primatology · December 1, 2021
The gut microbiome is gaining recognition for its role in primate nutrition, but we stand to benefit from microbiome comparisons across diverse hosts and environmental conditions. We compared gut microbiome structure in four lemur species from four phyloge ...
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Journal ArticleNature communications · December 2021
Female intrasexual competition can be intense in cooperatively breeding species, with some dominant breeders (matriarchs) limiting reproduction in subordinates via aggression, eviction or infanticide. In males, such tendencies bidirectionally link to testo ...
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Journal ArticleAnimal microbiome · October 2021
BackgroundAntibiotics alter the diversity, structure, and dynamics of host-associated microbial consortia, including via development of antibiotic resistance; however, patterns of recovery from microbial imbalances and methods to mitigate associat ...
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Journal ArticleFrontiers in Ecology and Evolution · August 9, 2021
The overuse of man-made antibiotics has facilitated the global propagation of antibiotic resistance genes in animals, across natural and anthropogenically disturbed environments. Although antibiotic treatment is the most well-studied route by which resista ...
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Journal ArticleAnimal microbiome · May 2021
BackgroundCaptive animals, compared to their wild counterparts, generally harbor imbalanced gut microbiota owing, in part, to their altered diets. This imbalance is particularly striking for folivores that fundamentally rely on gut microbiota for ...
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Journal ArticleScientific reports · February 2021
Contemporary theory that emphasizes the roles of oxytocin and vasopressin in mammalian sociality has been shaped by seminal vole research that revealed interspecific variation in neuroendocrine circuitry by mating system. However, substantial challenges ex ...
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Journal ArticleCurrent biology : CB · November 2020
Featured Publication
As chemicals that elicit unlearned, functionally specialized, and species-specific responses [1] or 'stereotyped behavior' [2], pheromones differ from mammalian scent signatures that comprise complex, variable mixtures, convey multiple messages via learned ...
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Journal ArticleThe Journal of endocrinology · October 2020
Featured Publication
The spotted hyaena (Crocuta crocuta) is a unique species, even amongst the Hyaenidae. Extreme clitoral development in female spotted hyaenas challenges aspects of the accepted framework of sexual differentiation and reproductive function. They lack a vulva ...
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Journal ArticleFrontiers in Endocrinology · September 30, 2024
IntroductionMammalian reproductive and somatic development is regulated by steroid hormones, growth hormone (GH), and insulin-like growth factor-1 (IGF-1). Based largely on information from humans, model organisms ...
Full textOpen AccessCite
Journal ArticleBiological reviews of the Cambridge Philosophical Society · April 2024
Microbiome science has provided groundbreaking insights into human and animal health. Similarly, evolutionary medicine - the incorporation of eco-evolutionary concepts into primarily human medical theory and practice - is increasingly recognised for its no ...
Full textCite
Journal ArticlePsychoneuroendocrinology · April 2023
A prominent body of research spanning disciplines has been focused on the potential underlying role for oxytocin in the social signatures of monogamous mating bonds. Behavioral differences between monogamous and non-monogamous vole species, putatively medi ...
Full textCite
Journal ArticleScientific reports · December 2022
Microbial rewilding, whereby exposure to naturalistic environments can modulate or augment gut microbiomes and improve host-microbe symbiosis, is being harnessed as an innovative approach to human health, one that may also have significant value to animal ...
Full textCite
Chapter · November 29, 2022
Stephen E. Glickman (1933-2020) was an American comparative psychologist and scholar of the history of psychology, who contributed over 100 publications relevant to the study of animal behavior, cognitive and behavioral neuroscience, reproductive neuroendo ...
Full textCite
Journal ArticleHormones and behavior · September 2022
This article is part of a Special Issue (Hormones and Hierarchies). To gain more balanced understanding of sexual selection and mammalian sexual differentiation processes, this review addresses behavioral sex differences and hormonal mediators of intrasexu ...
Full textCite
Journal ArticleAnimal microbiome · April 2022
BackgroundInter-population variation in host-associated microbiota reflects differences in the hosts' environments, but this characterization is typically based on studies comparing few populations. The diversity of natural habitats and captivity ...
Full textCite
Journal ArticleHormones and behavior · March 2022
In the decades since female social dominance was first described in strepsirrhine primates, researchers have sought to uncover the proximate and ultimate explanations for its development. In the females of various female-dominant species, androgens have be ...
Full textCite
Journal ArticleInternational Journal of Primatology · December 1, 2021
The gut microbiome is gaining recognition for its role in primate nutrition, but we stand to benefit from microbiome comparisons across diverse hosts and environmental conditions. We compared gut microbiome structure in four lemur species from four phyloge ...
Full textOpen AccessCite
Journal ArticleNature communications · December 2021
Female intrasexual competition can be intense in cooperatively breeding species, with some dominant breeders (matriarchs) limiting reproduction in subordinates via aggression, eviction or infanticide. In males, such tendencies bidirectionally link to testo ...
Full textCite
Journal ArticleAnimal microbiome · October 2021
BackgroundAntibiotics alter the diversity, structure, and dynamics of host-associated microbial consortia, including via development of antibiotic resistance; however, patterns of recovery from microbial imbalances and methods to mitigate associat ...
Full textCite
Journal ArticleFrontiers in Ecology and Evolution · August 9, 2021
The overuse of man-made antibiotics has facilitated the global propagation of antibiotic resistance genes in animals, across natural and anthropogenically disturbed environments. Although antibiotic treatment is the most well-studied route by which resista ...
Full textCite
Journal ArticleAnimal microbiome · May 2021
BackgroundCaptive animals, compared to their wild counterparts, generally harbor imbalanced gut microbiota owing, in part, to their altered diets. This imbalance is particularly striking for folivores that fundamentally rely on gut microbiota for ...
Full textCite
Journal ArticleScientific reports · February 2021
Contemporary theory that emphasizes the roles of oxytocin and vasopressin in mammalian sociality has been shaped by seminal vole research that revealed interspecific variation in neuroendocrine circuitry by mating system. However, substantial challenges ex ...
Full textCite
Journal ArticleCurrent biology : CB · November 2020
Featured Publication
As chemicals that elicit unlearned, functionally specialized, and species-specific responses [1] or 'stereotyped behavior' [2], pheromones differ from mammalian scent signatures that comprise complex, variable mixtures, convey multiple messages via learned ...
Full textCite
Journal ArticleThe Journal of endocrinology · October 2020
Featured Publication
The spotted hyaena (Crocuta crocuta) is a unique species, even amongst the Hyaenidae. Extreme clitoral development in female spotted hyaenas challenges aspects of the accepted framework of sexual differentiation and reproductive function. They lack a vulva ...
Full textCite
Journal ArticleThe ISME journal · July 2020
Featured Publication
If gut microbes influence host behavioral ecology in the short term, over evolutionary time, they could drive host niche differentiation. We explored this possibility by comparing the gut microbiota of Madagascar's folivorous lemurs from Indriidae and Lepi ...
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Journal ArticlePhilosophical transactions of the Royal Society of London. Series B, Biological sciences · June 2020
Featured Publication
The study of human chemical communication benefits from comparative perspectives that relate humans, conceptually and empirically, to other primates. All major primate groups rely on intraspecific chemosignals, but strepsirrhines present the greatest diver ...
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Journal ArticleFEMS microbiology ecology · June 2020
Host-associated microbiomes shape and are shaped by myriad processes that ultimately delineate their symbiotic functions. Whereas a host's stable traits, such as its lineage, relate to gross aspects of its microbiome structure, transient factors, such as i ...
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Journal ArticleAmerican journal of primatology · October 2019
Research on animal microbiomes is increasingly aimed at determining the evolutionary and ecological factors that govern host-microbiome dynamics, which are invariably intertwined and potentially synergistic. We present three empirical studies related to th ...
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Journal ArticleHormones and behavior · September 2019
The role of androgens in shaping "masculine" traits in males is a core focus in behavioral endocrinology, but relatively little is known about an androgenic role in female aggression and social dominance. In mammalian models of female dominance, including ...
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Journal ArticleBMC evolutionary biology · August 2019
BackgroundDiversity at the Major Histocompatibility Complex (MHC) is critical to health and fitness, such that MHC genotype may predict an individual's quality or compatibility as a competitor, ally, or mate. Moreover, because MHC products can inf ...
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Journal ArticleBiology letters · June 2019
Both host phylogenetic placement and feeding strategy influence the structure of the gut microbiome (GMB); however, parsing their relative contributions presents a challenge. To meet this challenge, we compared GMB structure in two genera of lemurs charact ...
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Journal ArticleFolia primatologica; international journal of primatology · January 2019
Scent marking is a well-established, but highly variable, mode of communication among strepsirrhine primates. We begin by reviewing this literature, focusing on nocturnal species. Our understanding about the information content of scent signals and the fac ...
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Journal ArticlePhysiology & behavior · September 2018
Meerkats are group-living, insectivorous herpestids in which subordinate members provide extensive care for the dominant female's young. In contrast to some cooperative breeders, subordinate female meerkats are physiologically able to reproduce and occasio ...
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Journal ArticleScientific reports · September 2018
The gut microbiome (GMB) of folivores metabolizes dietary fiber into nutrients, including short-chain fatty acids (SCFAs); however, experiments probing the consequences of foliage quality on host GMBs are lacking. We therefore examined GMB structure and fu ...
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Journal ArticleRoyal Society open science · August 2018
Social status can mediate effects on the immune system, with profound consequences for individual health; nevertheless, most investigators of status-related disparities in free-ranging animals have used faecal parasite burdens to proxy immune function in t ...
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Journal ArticleScientific reports · June 2018
Honesty is crucial in animal communication when signallers are conveying information about their condition. Condition dependence implies a cost to signal production; yet, evidence of such cost is scarce. We examined the effects of naturally occurring injur ...
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Chapter · January 1, 2018
The four, extant species of hyenids (aardwolves, striped hyenas, brown hyenas, and spotted hyenas) are compared and contrasted. Despite belonging to a small family of carnivorans, these species show a wide range of social systems (from solitary to gregario ...
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Journal ArticleEcology and evolution · October 2017
Across species, diversity at the major histocompatibility complex (MHC) is critical to individual disease resistance and, hence, to population health; however, MHC diversity can be reduced in small, fragmented, or isolated populations. Given the need for c ...
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Journal ArticleScientific reports · June 2017
The fermentation hypothesis for animal signalling posits that bacteria dwelling in an animal's scent glands metabolize the glands' primary products into odorous compounds used by the host to communicate with conspecifics. There is, however, little evidence ...
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Journal ArticleMicrobial ecology in health and disease · January 2017
Background: The gut microbiome (GMB) is the first line of defense against enteric pathogens, which are a leading cause of disease and mortality worldwide. One such pathogen, the protozoan Cryptosporidium, causes a variety of digestive disorde ...
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Journal ArticleBiology letters · October 2016
The immunocompetence handicap hypothesis posits that androgens in males can be a 'double-edged sword', actively promoting reproductive success, while also negatively impacting health. Because there can be both substantial androgen concentrations in females ...
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Journal ArticleDie Naturwissenschaften · June 2016
Members of the order Carnivora rely on urinary scent signaling, particularly for communicating about reproductive parameters. Here, we describe reproductive endocrine patterns in relation to urinary olfactory cues in a vulnerable and relatively unknown viv ...
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Journal ArticleRoyal Society Open Science · April 20, 2016
Animals communicating via scent often deposit composite signals that incorporate odorants from multiple sources; however, the function of mixing chemical signals remains understudied. We tested both a ‘multiple-messages’ and a ‘fixative’ hypothesis of comp ...
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Journal ArticleBMC genomics · March 2016
BackgroundAcross species, diversity at the Major Histocompatibility Complex (MHC) is critical to disease resistance and population health; however, use of MHC diversity to quantify the genetic health of populations has been hampered by the extreme ...
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Journal ArticleHormones and behavior · February 2016
In male vertebrates, androgens are inextricably linked to reproduction, social dominance, and aggression, often at the cost of paternal investment or prosociality. Testosterone is invoked to explain rank-related reproductive differences, but its role withi ...
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Journal ArticleBehavioral Ecology · January 1, 2016
Within animal societies, demographic and social factors, as well as the different reproductive efforts of group members, may influence individual patterns of reproductive success and parasitism. In mammals, such relationships have been studied primarily in ...
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Journal ArticleScientific reports · May 2015
Female social dominance (FSD) over males is unusual in mammals, yet characterizes most Malagasy lemurs, which represent almost 30% of all primates. Despite its prevalence in this suborder, both the evolutionary trajectory and proximate mechanism of FSD rem ...
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Journal ArticleBiology Letters · February 25, 2015
Jeremy Chase Crawford1,2,3,4 and Christine M. Drea4,5⇑1National Evolutionary Synthesis Center, Durham, NC, USA2Department of Integrative Biology, University of California, Berkeley, CA, USA3Museum of Vertebrate Zoology, University of California, Berkeley, ...
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Journal ArticleHormones and behavior · February 2015
This article is part of a Special Issue (Chemosignals and Reproduction). As highly visual animals, primates, in general, and Old World species (including humans), in particular, are not immediately recognized for reliance in their daily interactions on olf ...
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Journal ArticleAnimal Behaviour · November 1, 2014
Our understanding of chemical signals in mammals derives principally from studies in which researchers examine signal structure or function within a single species. Despite the unique information to be gained from applying comparable methods across multipl ...
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Journal ArticleProceedings. Biological sciences · June 2014
Individual recognition can be facilitated by creating representations of familiar individuals, whereby information from signals in multiple sensory modalities become linked. Many vertebrate species use auditory-visual matching to recognize familiar conspec ...
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Journal ArticleAnimal Behaviour · February 1, 2014
Social complexity, often estimated by group size, is seen as driving the complexity of vocal signals, but its relation to olfactory signals, which arguably arose to function in nonsocial realms, remains underappreciated. That olfactory signals also may med ...
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Journal ArticleDifferentiation; research in biological diversity · January 2014
This review/research paper summarizes data on development of the external genitalia of the spotted hyena, a fascinating mammal noted for extreme masculinization of the female external genitalia. The female spotted hyena is the only extant mammal that mates ...
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Journal ArticleBehavioral Ecology · January 1, 2014
The contribution of bacterial fermentation to the production of vertebrate scent signals has long been suspected, but there is still relatively little information about the factors driving variation in microbial composition in animal scent secretions. Our ...
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Journal ArticleAmerican journal of primatology · July 2013
Urine serves a communicative function in many mammalian species. In some species, the signaling function of urine can be enhanced by the addition of chemical compounds from glands along the distal portion of the urogenital tract. Although urine marking is ...
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Journal ArticleAmerican journal of primatology · July 2013
Olfactory communication in primates is gaining recognition; however, studies on the production and perception of primate scent signals are still scant. In general, there are five tasks to be accomplished when deciphering the chemical signals contained in e ...
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Journal ArticleAmerican journal of primatology · July 2013
Compared to other modes of communication, chemical signaling between conspecifics generally has been overlooked in Old World primates, despite the presence in this group of secretory glands and scent-marking behavior, as well as the confirmed production an ...
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Journal ArticlePloS one · January 2013
The aggression animals receive from conspecifics varies between individuals across their lifetime. As poignantly evidenced by infanticide, for example, aggression can have dramatic fitness consequences. Nevertheless, we understand little about the sources ...
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Journal ArticlePhilosophical transactions of the Royal Society of London. Series B, Biological sciences · July 2012
Signal complexity has been linked to social complexity in vocal, but not chemical, communication. To address this gap, we examined the chemical complexity of male and female glandular secretions in eight species of Eulemur. In this diverse clade of macrosm ...
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Journal ArticleEndocrinology · March 2012
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). Be ...
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Journal ArticleAnim Cogn · March 2012
Now more than ever animal studies have the potential to test hypotheses regarding how cognition evolves. Comparative psychologists have developed new techniques to probe the cognitive mechanisms underlying animal behavior, and they have become increasingly ...
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Journal ArticlePloS one · January 2012
Visual and olfactory cues provide important information to foragers, yet we know little about species differences in sensory reliance during food selection. In a series of experimental foraging studies, we examined the relative reliance on vision versus ol ...
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Journal ArticleAmerican Journal of Primatology · 2012
Compared to other modes of communication, chemical signaling generally has been overlooked in Old World primates, despite the presence in this group of secretory glands and scent-marking behavior, as well as the confirmed production and perception of consp ...
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Journal ArticleHormones and behavior · April 2011
Female ring-tailed lemurs (Lemur catta) are Malagasy primates that are size monomorphic with males, socially dominate males, and exhibit a long, pendulous clitoris, channeled by the urethra. These masculine traits evoke certain attributes of female spotted ...
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Journal ArticleGeneral and comparative endocrinology · February 2011
The androgen receptor blocker flutamide and the 5α-reductase inhibitor finasteride have been used in a variety of species to investigate the ontogeny of sexual dimorphisms by treating pregnant females or neonates at critical periods of sexual differentiati ...
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Journal ArticleJournal of evolutionary biology · January 2011
Studies of chemical signals in vertebrates typically target single species; however, a broader understanding of olfactory communication may derive from comparative studies. We collected urine from 12 species representing most families of strepsirrhine prim ...
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Journal ArticleProc Roy Soc, B · 2011
Animals, including humans, use olfaction to assess potential social and sexual partners. Although hormones modulate olfactory cues, we know little about whether contraception affects semiochemical signals and, ultimately, mate choice. We examined the effec ...
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Journal ArticleJournal of evolutionary biology · July 2010
Sexual selection theory predicts that potential mates or competitors signal their quality to conspecifics. Whereas evidence of honest visual or vocal signals in males abounds, evidence of honest signalling via scent or by females is scarce. We previously s ...
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Journal ArticleHormones and behavior · January 2010
Fecal glucocorticoid (fGC) concentrations are reliable, non-invasive indices of physiological stress that provide insight into an animal's energetic and social demands. To better characterize the long-term stressors in adult members of a female-dominant, s ...
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Journal ArticleAnimal Behaviour · 2010
To enhance the fitness benefits of social and sexual interaction, animals should be able to decipher information about the genetic makeup of conspecifics. The use of relative criteria to estimate genetic relatedness could facilitate nepotism or inbreeding ...
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Journal ArticleBMC evolutionary biology · December 2009
BackgroundLike other vertebrates, primates recognize their relatives, primarily to minimize inbreeding, but also to facilitate nepotism. Although associative, social learning is typically credited for discrimination of familiar kin, discrimination ...
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Journal ArticleAnimal Behaviour · October 1, 2009
Numerous field researchers have described cooperative hunting in social carnivores, but experimental evidence of cooperative problem solving typically derives from laboratory studies of nonhuman primates. We present the first experimental evidence of coope ...
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Journal ArticleCurrent Directions in Psychological Science · August 1, 2009
Most mammal species show traditional patterns of sexual dimorphism (e.g., greater male size and aggression), the proximal mechanism of which involves the male's greater pre- and postnatal exposure to circulating androgens. But in several species, females d ...
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Journal ArticleBehavioral Ecology · January 12, 2009
Among primates, catarrhines (Old World monkeys and apes) and certain platyrrhines (New World monkeys) possess trichromatic color vision, which might confer important evolutionary advantages, particularly during foraging. Recently, a polymorphism has been s ...
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Journal ArticleMolecular ecology · July 2008
Sexual selection theory predicts that competitors or potential mates signal their quality or relatedness to conspecifics. Researchers have focused on visual or auditory modes of signal transmission; however, the importance of olfactory indicators is gainin ...
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Journal ArticleJournal of morphology · April 2008
The extravagance and diversity of external genitalia have been well characterized in male primates; however, much less is known about sex differences or variation in female form. Our study represents a departure from traditional investigations of primate r ...
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Journal ArticleConservation Genetics · January 1, 2008
The consequences of inbreeding have been well studied in a variety of taxa, revealing that inbreeding has major negative impacts in numerous species, both in captivity and in the wild; however, as trans-generational health data are difficult to obtain for ...
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Journal ArticleChemical senses · June 2007
The apocrine and sebaceous scent glands of ringtailed lemurs (Lemur catta) appear to serve different social functions. In behavioral experiments, lemurs modulate their responses to scent marks based on the type of odorant, their own physiological state, th ...
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Journal ArticleHormones and behavior · April 2007
Female social dominance characterizes many strepsirrhine primates endemic to Madagascar, but currently there is no comprehensive explanation for how or why female lemurs routinely dominate males. Reconstructing the evolutionary pressures that may have shap ...
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Journal ArticleAnimal Behaviour · February 1, 2007
The function of olfactory signalling in social species is less well understood than in asocial species. Consequently, we examined olfactory communication in the ringtailed lemur, a socially complex primate that retains a functional vomeronasal organ, has w ...
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Journal ArticleTrends in endocrinology and metabolism: TEM · November 2006
Female spotted hyenas (Crocuta crocuta) are the only female mammals that lack an external vaginal opening. Mating and birth take place through a urogenital canal that exits at the tip of a hypertrophied clitoris. This 'masculine' phenotype spurred a search ...
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Journal ArticleMethods (San Diego, Calif.) · March 2006
Learning commonly refers to the modification of behavior through experience, whereby an animal gains information about stimulus-response contingencies from interacting with its physical environment. Social learning, on the other hand, occurs when the same ...
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Journal ArticleIntegrative and comparative biology · November 2005
The breeding system of an animal population is thought to depend on the ability of one sex (usually the male) to acquire mates, either directly through association with females or indirectly through defense of the resources desired by females. The sex that ...
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Journal ArticleJournal of comparative psychology (Washington, D.C. : 1983) · December 2002
Olfaction is crucial to spotted hyenas (Crocuta crocuta), yet there are no controlled studies of their reactions to odors. In Experiment 1, the authors examined responses of captive hyenas to various environmental (prey, nonprey animal, and plant) odors. S ...
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Journal ArticleBiology of reproduction · November 2002
Prenatal androgen treatment can alter LH secretion in female offspring, often with adverse effects on ovulatory function. However, female spotted hyenas (Crocuta crocuta), renowned for their highly masculinized genitalia, are naturally exposed to high andr ...
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Journal ArticleProceedings. Biological sciences · October 2002
Among all extant mammals, only the female spotted hyena (Crocuta crocuta) mates and gives birth through the tip of a peniform clitoris. Clitoral morphology is modulated by foetal exposure to endogenous, maternal androgens. First births through this organ a ...
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Journal ArticleJournal of Comparative Psychology · 2002
Scent marking in spotted hyenas (Crocuta crocuta)
includes the deposition of anal sac secretions, or “paste,”
and presumably advertises territorial ownership. To test
whether captive hyenas classify and discriminate
individuals using odor cues in paste ...
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Journal ArticleProceedings of the National Academy of Sciences of the United States of America · October 1999
Many primates, including humans, live in complex hierarchical societies where social context and status affect daily life. Nevertheless, primate learning studies typically test single animals in limited laboratory settings where the important effects of so ...
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Journal ArticleJournal of comparative psychology (Washington, D.C. : 1983) · June 1998
To assess the relation between performance and social or demographic variables, this study group tested a captive monkey colony on visual and manual discrimination problems. Animals could choose between differently colored, sand-filled boxes, where hue sig ...
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Journal ArticleJournal of reproduction and fertility · May 1998
Pregnant spotted hyaenas were treated with anti-androgens to interfere with the unusually masculine 'phallic' development that characterizes females of this species. The effects on genital morphology and plasma androgen concentrations of infants were studi ...
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Journal ArticleJournal of reproduction and fertility · May 1998
Studies involving the administration of anti-androgens to spotted hyaenas during fetal development have raised questions concerning the precise contributions of steroids to phallic growth in these animals. If gonadal androgens promote postnatal penile grow ...
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Journal ArticleAmerican Journal of Primatology · 1998
This study reports on social modulation of exploratory
behavior and response to novelty by members of a captive
rhesus monkey colony. The group was trained to split in
half, with one subgroup composed of dominant members
only, the other of subordinate ...
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Journal ArticleAmerican journal of primatology · January 1998
This study reports on social modulation of exploratory behavior and response to novelty by members of a captive rhesus monkey colony. The group was trained to split in half, with one subgroup composed of dominant members only, the other of subordinates. Th ...
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Journal ArticleAnimal Behaviour · January 1, 1996
The early social development of spotted hyaenas, Crocuta crocuta, is marked by a dramatic transition at 2-3 weeks of age, when infants are taken from the isolation of their natal den, where they are intensely aggressive, to the communal den, where they mee ...
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Journal ArticlePhysiology & behavior · December 1995
This study investigated the relationship between neonatal testosterone (T) and hand bias in young rhesus monkeys (Macaca mulatta). Subjects (n = 8 per group) included: neonatally androgen-suppressed males, using a Nal-Lys gonadotropin releasing hormone (Gn ...
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Journal ArticleAnimal Learning & Behavior · March 1, 1995
An established, captive colony of 74 rhesus monkeys (Macaca mulatta) was group-tested on a simultaneous visual discrimination problem and three reversals of the initial discrimination. The task incorporated important aspects of rhesus foraging behavior. Al ...
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Journal ArticleJournal of comparative psychology (Washington, D.C. : 1983) · September 1991
Asymmetrical hand use by rhesus monkeys (Macaca mulatta) was investigated in a series of tactually and visually guided tasks. The 1st experiment recorded manual preferences of 29 monkeys for solving a haptic discrimination task in a hanging posture. There ...
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Journal ArticleJournal of comparative psychology (Washington, D.C. : 1983) · 1991
Asymmetrical hand use by rhesus monkeys (Macaca mulatta) was investigated in a series of tactually and visually guided tasks. The 1st experiment recorded manual preferences of 29 monkeys for solving a haptic discrimination task in a hanging posture. There ...
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Journal ArticleExperimental eye research · May 1989
Polyol accumulation and myo-inositol depletion were accompanied by extensive vacuole formation in cultured canine lens epithelial cells that were incubated for up to 96 hr in growth medium supplemented with 30 mM D-galactose or 30 mM D-glucose. These chang ...
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Journal ArticleExperimental eye research · June 1987
Vitamin A plays a central role in visual transduction and in maintaining the structural integrity of the retina. It is possible that age-related alterations in vitamin A metabolism in the eye could contribute to the impairment of visual function that occur ...
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Journal ArticleBiochimica et biophysica acta · June 1987
Experiments were conducted to determine the influence of dietary levels of vitamin A and alpha-tocopherol on the amounts and composition of retinyl esters in the retinal pigment epithelium of light-adapted albino rats. Groups of rats were fed diets contain ...
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Journal ArticleExperimental eye research · October 1986
Experiments were conducted to evaluate the role played by photoreceptor cells in the accumulation of age pigment, or lipofuscin, in the retinal pigment epithelium (RPE). The age-related accumulation of RPE lipofuscin was compared between rats with heredita ...
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Journal ArticleMechanisms of ageing and development · August 1986
A variety of evidence suggests that autoxidation of cellular components probably plays a significant role in the age-related accumulation of lipofuscin, or age-pigment, in the mammalian retinal pigment epithelium (RPE). Among the likely candidates for conv ...
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