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Martínez L, de Andrés PJ, Caperos JM, Silván G, Fernández-Morán J, Casares M, Crespo B, Vélez D, Sanz L, Cáceres S, Illera JC. Predicting Sex in White Rhinoceroses: A Statistical Model for Conservation Management. Animals (Basel) 2023; 13:2583. [PMID: 37627374 PMCID: PMC10451157 DOI: 10.3390/ani13162583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/13/2023] [Accepted: 08/08/2023] [Indexed: 08/27/2023] Open
Abstract
Ensuring the effective management of every rhinoceros population is crucial for securing a future for the species, especially considering the escalating global threat of poaching and the challenges faced in captive breeding programs for this endangered species. Steroid hormones play pivotal roles in regulating diverse biological processes, making fecal hormonal determinations a valuable non-invasive tool for monitoring adrenal and gonadal endocrinologies and assessing reproductive status, particularly in endangered species. The purpose of this study was to develop a statistical model for predicting the sex of white rhinoceroses using hormonal determinations obtained from a single fecal sample. To achieve this, 562 fecal samples from 15 individuals of the Ceratotherium simum species were collected, and enzyme immunoassays were conducted to determine the concentrations of fecal cortisol, progesterone, estrone, and testosterone metabolites. The biological validation of the method provided an impressive accuracy rate of nearly 80% in predicting the sex of hypothetically unknown white rhinoceroses. Implementing this statistical model for sex identification in white rhinoceroses would yield significant benefits, including a better understanding of the structure and dynamics of wild populations. Additionally, it would enhance conservation management efforts aimed at protecting this endangered species. By utilizing this innovative approach, we can contribute to the preservation and long-term survival of white rhinoceros populations.
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Affiliation(s)
- Leticia Martínez
- Department of Animal Physiology, Veterinary Faculty, Complutense University of Madrid, 28040 Madrid, Spain
| | - Paloma Jimena de Andrés
- Department of Animal Medicine and Surgery, Veterinary Faculty, Complutense University of Madrid, 28040 Madrid, Spain
| | - Jose Manuel Caperos
- Clinical Psychology Unit (UNINPSI), Department of Psychology, Comillas Pontifical University, Calle Mateo Inurria 37, 28036 Madrid, Spain
| | - Gema Silván
- Department of Animal Physiology, Veterinary Faculty, Complutense University of Madrid, 28040 Madrid, Spain
| | | | - Miguel Casares
- Bioparc Valencia, Avenida Pio Baroja 3, 46015 Valencia, Spain
| | - Belén Crespo
- Department of Animal Physiology, Veterinary Faculty, Complutense University of Madrid, 28040 Madrid, Spain
| | - Daniel Vélez
- Department of Statistics and Operational Research, Faculty of Mathematics, Complutense University of Madrid, 28040 Madrid, Spain
| | - Luis Sanz
- Department of Statistics and Operational Research, Faculty of Mathematics, Complutense University of Madrid, 28040 Madrid, Spain
| | - Sara Cáceres
- Department of Animal Physiology, Veterinary Faculty, Complutense University of Madrid, 28040 Madrid, Spain
| | - Juan Carlos Illera
- Department of Animal Physiology, Veterinary Faculty, Complutense University of Madrid, 28040 Madrid, Spain
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2
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Bhandari S, Adhikari B, Baral K, Subedi SC. Greater one-horned rhino (Rhinoceros unicornis) mortality patterns in Nepal. Glob Ecol Conserv 2022. [DOI: 10.1016/j.gecco.2022.e02189] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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3
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Penny SG, Withey M, White RL, Scott DM, MacTavish L, Pernetta AP. Changes in social dominance in a group of subadult white rhinoceroses ( Ceratotherium simum) after dehorning. AFRICAN ZOOLOGY 2022. [DOI: 10.1080/15627020.2022.2046155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Samuel G Penny
- Ecology, Conservation and Zoonosis Research Group, School of Applied Sciences, University of Brighton, United Kingdom
- Bristol Zoological Society, Clifton, Bristol, United Kingdom
| | - Maxim Withey
- Ecology, Conservation and Zoonosis Research Group, School of Applied Sciences, University of Brighton, United Kingdom
| | - Rachel L White
- Ecology, Conservation and Zoonosis Research Group, School of Applied Sciences, University of Brighton, United Kingdom
| | - Dawn M Scott
- School of Animal, Rural and Environmental Sciences, Nottingham Trent University, United Kingdom
| | - Lynne MacTavish
- Ecology, Conservation and Zoonosis Research Group, School of Applied Sciences, University of Brighton, United Kingdom
| | - Angelo P Pernetta
- Ecology, Conservation and Zoonosis Research Group, School of Applied Sciences, University of Brighton, United Kingdom
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4
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Cassini MH. Evolution of sexual size dimorphism and sexual segregation in artiodactyls: the chicken or the egg? Mamm Biol 2021. [DOI: 10.1007/s42991-021-00193-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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5
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Stratford KJ, Guerier AS, Crawford SJ, Stratford SMC, Schmidt-Küntzel A, Bishop JM. Female Southern White Rhinoceros Can Select Mates to Avoid Inbreeding. J Hered 2021; 112:385-390. [PMID: 33950221 DOI: 10.1093/jhered/esab028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 04/30/2021] [Indexed: 01/02/2023] Open
Abstract
Current management models for many endangered species focus primarily on demographic recovery, often ignoring their intrinsic ecological requirements. Across the protected area network of southern Africa, most southern white rhinoceros are managed in populations of less than 50 individuals, experiencing restricted dispersal opportunities, and limited breeding male numbers due to their exclusive home range requirements. In the absence of information on the breeding structure of these populations, poor management decisions may require females to either forego a breeding opportunity or select to inbreed with close relatives. Here, we use a combination of social pedigree data together with genetic analyses to reconstruct the parentage of all 28 offspring produced in a 5-year period in a managed free-ranging southern white rhinoceros population. During this period, all breeding females (founders and first-generation daughters) had access to both a founder male (father to most of the daughters) and two recently introduced inexperienced males. We report that while founder females were more likely to breed with the founder male, their daughters, in contrast, were more likely to breed with the introduced males, thus avoiding inbreeding. However, we also found evidence of father-daughter inbreeding in this population, and contend that in the absence of choice, rather than forego a breeding opportunity, female white rhinoceros will inbreed with their fathers. We argue that to effectively conserve the southern white rhinoceros, managers need to understand the breeding structure of these small populations, particularly in terms of parentage and kinship.
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Affiliation(s)
| | | | | | | | - Anne Schmidt-Küntzel
- Life Technologies Conservation Genetics Laboratory, Cheetah Conservation Fund, Otjiwarongo, Namibia
| | - Jacqueline M Bishop
- Institute for Communities and Wildlife in Africa, Department of Biological Sciences, University of Cape Town, Rondebosch, Cape Town, South Africa
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6
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Jenikejew J, Wauters J, Dehnhard M, Scheumann M. The female effect-how female receptivity influences faecal testosterone metabolite levels, socio-positive behaviour and vocalization in male Southern white rhinoceroses. CONSERVATION PHYSIOLOGY 2021; 9:coab026. [PMID: 33959291 PMCID: PMC8084027 DOI: 10.1093/conphys/coab026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 01/09/2021] [Accepted: 03/29/2021] [Indexed: 06/12/2023]
Abstract
Testosterone is known to be essential for sexual maturation as well as for the display of behavioural traits linked to reproduction. At the same time, external factors such as the presence of receptive females may affect testosterone levels, stressing the hormone's substantial role in reproductive success. It is therefore of major interest to investigate the links between androgens, behaviour and the social environment especially in species that rely on a resilient reproduction rate, such as the white rhinoceros (WR). We collected faecal samples of 16 male Southern WR (Ceratotherium simum simum) aged between 1 and 44 years from 11 European zoos. Audio and video recordings were simultaneously taken from five of the study males that were sexually mature and had direct contact with receptive females. Our results showed a positive correlation of faecal testosterone metabolite (fTM) concentrations and progressing age up until adulthood followed by a decline in older males. While previous reproductive success did not show any effect, the access to receptive females resulted in higher fTM levels. Thereby, fTM concentrations remained at the same level regardless of the receptivity phase, while social cohesion with respective females, affiliative behaviour as well as call rates of Pant and Hiss distinctly peaked during the receptive compared to the non-receptive periods. Conclusively, the immediate presence of receptive females poses a female effect that enhances the overall androgen levels in males and, thus, might facilitate their reproductive success. However, androgens do not seem to be the main driver of behavioural changes during courtship or mating. By linking endocrinological and socio-behavioural factors, we were able to provide an applicable basis for non-invasive monitoring of reproductive behaviour in male WR in captivity, thereby contributing to deeper understanding of potential reproduction impairments in a species whose population in captivity remains not fully self-sustaining.
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Affiliation(s)
- Julia Jenikejew
- Institute of Zoology, University of Veterinary Medicine Hannover, Bünteweg 17, 30559 Hannover, Germany
| | - Jella Wauters
- Department of Reproduction Biology, Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Straße 17, 10315 Berlin, Germany
| | - Martin Dehnhard
- Department of Reproduction Biology, Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Straße 17, 10315 Berlin, Germany
| | - Marina Scheumann
- Institute of Zoology, University of Veterinary Medicine Hannover, Bünteweg 17, 30559 Hannover, Germany
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Cinková I, Shrader AM. Rival assessment by territorial southern white rhinoceros males via eavesdropping on the contact and courtship calls. Anim Behav 2020. [DOI: 10.1016/j.anbehav.2020.05.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Bowyer RT, McCullough DR, Rachlow JL, Ciuti S, Whiting JC. Evolution of ungulate mating systems: Integrating social and environmental factors. Ecol Evol 2020; 10:5160-5178. [PMID: 32551090 PMCID: PMC7297761 DOI: 10.1002/ece3.6246] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 03/12/2020] [Accepted: 03/13/2020] [Indexed: 11/25/2022] Open
Abstract
Ungulates exhibit diverse mating systems that range from monogamous pair territories to highly polygynous leks. We review mating systems and behaviors across ungulates and offer a new approach synthesizing how interacting factors may shape those mating systems. Variability exists in mating systems among and within species of ungulates and likely is affected by predation risk, availability of resources (food and mates), habitat structure, and sociality. Ungulate mating systems may be labile as a consequence of the varying strength of those interacting factors. In addition, degree of polygyny and sexual dimorphism in size are associated with the evolution of mating systems. Neither male-male combat nor paternal care, however, can completely explain differences in sexual size dimorphism for ungulates, a necessary component in understanding the development of some mating systems. Whatever the evolutionary pathway, sexual segregation limits paternal care allowing more intense male-male competition. Selection of habitat structure, because it modifies risk of predation, is a major determinant of sociality for ungulates. Likewise, ruggedness and steepness of terrain limit the types of mating systems that can occur because of limitations in group size and cohesiveness, as well as the ability of males to herd even small groups of females effectively. The quality and defensibility of resources affect mating systems, as does the defensibility of females. Population density of females also may be a critical determinant of the types of mating systems that develop. Size of groups likewise constrains the types of mating tactics that males can employ. Our aim was to use those relationships to create a broad conceptual model that predicts how various environmental and social factors interact to structure mating systems in ungulates. This model provides a useful framework for future tests of the roles of both ecological and social conditions in influencing the social systems of ungulates.
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Affiliation(s)
- R. Terry Bowyer
- Institute of Arctic BiologyUniversity of Alaska FairbanksFairbanksAKUSA
| | - Dale R. McCullough
- Department of Environmental Science, Policy and ManagementUniversity of CaliforniaBerkeleyCAUSA
| | - Janet L. Rachlow
- Department of Fish and Wildlife SciencesUniversity of IdahoMoscowIDUSA
| | - Simone Ciuti
- Laboratory of Wildlife Ecology and BehaviourSchool of Biology and Environmental ScienceUniversity College DublinDublinIreland
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Kretzschmar P, Auld H, Boag P, Gansloßer U, Scott C, Van Coeverden de Groot PJ, Courtiol A. Mate choice, reproductive success and inbreeding in white rhinoceros: New insights for conservation management. Evol Appl 2020; 13:699-714. [PMID: 32211061 PMCID: PMC7086106 DOI: 10.1111/eva.12894] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 10/04/2019] [Accepted: 10/29/2019] [Indexed: 12/15/2022] Open
Abstract
Improving our sparse knowledge of the mating and reproductive behaviour of white rhinoceros (Ceratotherium simum Burchell, 1817) is essential for the effective conservation of this iconic species. By combining morphological, physiological and habitat data with paternity assignments of 104 known mother-offspring pairs collected over a period of 13 years, we provide the most comprehensive analysis of the mating system in this species. We show that while the overall mating system was promiscuous, and both males and females produced more offspring when mating with several partners, half of all females with multiple offspring were monogamous. Additionally, we find that mating and reproductive success varied significantly among territorial males in two independent sets of males. In females, however, variation in the mating and the reproductive success was not larger than expected by random demographic fluctuations. Horn size, testosterone metabolite concentration, territory size, habitat openness and the volume of preferred food within the territory did not seem to influence male mating or reproductive success. Moreover, there was no sign of inbreeding avoidance: females tended to mate more frequently with closely related males, and one daughter produced a progeny with her father. The lack of inbreeding avoidance, in combination with the skew in male reproductive success, the partial monogamy in females and the territorial-based mating system, jeopardizes the already low genetic variation in the species. Considering that the majority of populations are restricted to fenced reserves and private farms, we recommend taking preventive measures that aim to reduce inbreeding in white rhinoceros. A video abstract can be viewed here.
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Affiliation(s)
- Petra Kretzschmar
- Department of Evolutionary EcologyLeibniz Institute for Zoo and Wildlife ResearchBerlinGermany
| | - Hailie Auld
- Department of BiologyQueen's UniversityKingstonOntarioCanada
| | - Peter Boag
- Department of BiologyQueen's UniversityKingstonOntarioCanada
| | - Udo Gansloßer
- Zoological Institute and Museum of Greifswald UniversityGreifswaldGermany
- Institute of Zoology and Evolutionary ResearchFriedrich Schiller UniversityJenaGermany
| | - Candace Scott
- Department of BiologyQueen's UniversityKingstonOntarioCanada
- Department of Applied Sciences and ComputingSt. Lawrence CollegeKingstonOntarioCanada
| | | | - Alexandre Courtiol
- Department of Evolutionary GeneticsLeibniz Institute for Zoo and Wildlife ResearchBerlinGermany
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Purisotayo T, Jonsson NN, Mable BK, Verreynne FJ. Combining molecular and incomplete observational data to inform management of southern white rhinoceros (Ceratotherium simum simum). CONSERV GENET 2019. [DOI: 10.1007/s10592-019-01166-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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11
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Rico-Guevara A, Hurme KJ. Intrasexually selected weapons. Biol Rev Camb Philos Soc 2019; 94:60-101. [PMID: 29924496 DOI: 10.1111/brv.12436] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 05/14/2018] [Accepted: 05/18/2018] [Indexed: 01/24/2023]
Abstract
We propose a practical concept that distinguishes the particular kind of weaponry that has evolved to be used in combat between individuals of the same species and sex, which we term intrasexually selected weapons (ISWs). We present a treatise of ISWs in nature, aiming to understand their distinction and evolution from other secondary sex traits, including from 'sexually selected weapons', and from sexually dimorphic and monomorphic weaponry. We focus on the subset of secondary sex traits that are the result of same-sex combat, defined here as ISWs, provide not previously reported evolutionary patterns, and offer hypotheses to answer questions such as: why have only some species evolved weapons to fight for the opposite sex or breeding resources? We examined traits that seem to have evolved as ISWs in the entire animal phylogeny, restricting the classification of ISW to traits that are only present or enlarged in adults of one of the sexes, and are used as weapons during intrasexual fights. Because of the absence of behavioural data and, in many cases, lack of sexually discriminated series from juveniles to adults, we exclude the fossil record from this review. We merge morphological, ontogenetic, and behavioural information, and for the first time thoroughly review the tree of life to identify separate evolution of ISWs. We found that ISWs are only found in bilateral animals, appearing independently in nematodes, various groups of arthropods, and vertebrates. Our review sets a reference point to explore other taxa that we identify with potential ISWs for which behavioural or morphological studies are warranted. We establish that most ISWs come in pairs, are located in or near the head, are endo- or exoskeletal modifications, are overdeveloped structures compared with those found in females, are modified feeding structures and/or locomotor appendages, are most common in terrestrial taxa, are frequently used to guard females, territories, or both, and are also used in signalling displays to deter rivals and/or attract females. We also found that most taxa lack ISWs, that females of only a few species possess better-developed weapons than males, that the cases of independent evolution of ISWs are not evenly distributed across the phylogeny, and that animals possessing the most developed ISWs have non-hunting habits (e.g. herbivores) or are faunivores that prey on very small prey relative to their body size (e.g. insectivores). Bringing together perspectives from studies on a variety of taxa, we conceptualize that there are five ways in which a sexually dimorphic trait, apart from the primary sex traits, can be fixed: sexual selection, fecundity selection, parental role division, differential niche occupation between the sexes, and interference competition. We discuss these trends and the factors involved in the evolution of intrasexually selected weaponry in nature.
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Affiliation(s)
- Alejandro Rico-Guevara
- Department of Integrative Biology, University of California, Berkeley, 3040 Valley Life Sciences Building, Berkeley, CA, 94720, U.S.A.,Department of Ecology and Evolutionary Biology, University of Connecticut, 75 N. Eagleville Rd, Unit 3043, Storrs, CT, 06269, U.S.A.,Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Código Postal 11001, Bogotá DC, Colombia
| | - Kristiina J Hurme
- Department of Integrative Biology, University of California, Berkeley, 3040 Valley Life Sciences Building, Berkeley, CA, 94720, U.S.A.,Department of Ecology and Evolutionary Biology, University of Connecticut, 75 N. Eagleville Rd, Unit 3043, Storrs, CT, 06269, U.S.A
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12
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Ritualised Dung Kicking by White Rhino Males Amplifies Olfactory Signals but Reduces Odour Duration. J Chem Ecol 2018; 44:875-885. [PMID: 30009329 DOI: 10.1007/s10886-018-0988-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 05/16/2018] [Accepted: 07/06/2018] [Indexed: 10/28/2022]
Abstract
Many mammals enhance their olfactory signals visually by depositing them in conspicuous locations such as well-travelled paths. It is also possible to enhance the odour itself through behaviours aimed at modifying odour emission rates. White rhinos defecate in communal middens. While defecating, territorial males kick sharply with their back feet which disperses their dung. Despite being a ubiquitous trait of territorial male white rhinos, the reason behind this behaviour is unclear. We hypothesised that the purpose of dung kicking was for olfactory signal amplification (OSA) in terms of an increased emission of volatile compounds (i.e. increased signal strength). Using dung collected from non-territorial adult males (because it is not possible to collect whole dung from territorial males), we show that the dispersal of male white rhino dung causes OSA by increasing the emission of hydrocarbon acids. The dung odour of territorial and non-territorial males differs only quantitatively, hence it is likely that the same emission patterns occur for territorial male dung odours following dung dispersal. The volatile compound indicating age of intact dung was toluene, but for dispersed dung it was acetophenone (similar to territorial male dung). Despite the benefits of OSA, dung dispersal carried a cost of decreased odour longevity. Thus, signal detectability is temporally reduced. However, territorial males likely counteract this by defecating in middens both before and during peak visitation times by other individuals (15:00-23:00). As a result, we suggest that dung kicking by territorial males amplifies signal strength, such that their dung odours are the most prominent and easily detectable by individuals visiting the middens. This would then better signal territorial ownership to both potential rivals and potential mates.
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Marneweck C, Jürgens A, Shrader AM. Dung odours signal sex, age, territorial and oestrous state in white rhinos. Proc Biol Sci 2018; 284:rspb.2016.2376. [PMID: 28077775 DOI: 10.1098/rspb.2016.2376] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 12/06/2016] [Indexed: 11/12/2022] Open
Abstract
Mammals commonly communicate olfactorily via urine. However, the extent to which they communicate via dung, another waste product, is unknown. Behavioural studies suggest that mammals can obtain information from dung odours but are unclear about the information transmitted. Moreover, an understanding of the volatile organic compounds (VOCs) released from dung is limited. To address this, we analysed the odours emitted from the dung of free-ranging white rhinos, and found that 2,3-dimethylundecane signalled an individual's sex, heptanal discriminated age class, nonane defined male territorial status and 2,6-dimethylundecane indicated female oestrous state. To validate these findings, we artificially reproduced key elements of the territorial and oestrous odour profiles (i.e. profiles likely to elicit behavioural responses from receivers). We then exposed free-ranging territorial males to these odours. In response, males elicited behaviours associated with the specific odours (e.g. territorial male (potential threat): reduced latency in assuming vigilance; oestrous female (potential mate): increased investigation). These results indicate that the VOCs identified from the dung of free-ranging individuals do transmit key information. Moreover, as white rhinos of all ages and sexes defecate communally, middens probably act as information centres. Furthermore, as many other mammals defecate communally, olfactory communication via dung odours is likely a widespread phenomenon.
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Affiliation(s)
- Courtney Marneweck
- School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - Andreas Jürgens
- Chemical Plant Ecology, Technische Universität Darmstadt, Darmstadt, Germany
| | - Adrian M Shrader
- School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
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14
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Jordan NR, Buse C, Wilson AM, Golabek KA, Apps PJ, Lowe JC, Van der Weyde LK, Weldon McNutt J. Dynamics of direct inter-pack encounters in endangered African wild dogs. Behav Ecol Sociobiol 2017. [DOI: 10.1007/s00265-017-2338-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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15
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Male ruff colour as a rank signal in a monomorphic-horned mammal: behavioural correlates. Naturwissenschaften 2015; 102:39. [DOI: 10.1007/s00114-015-1290-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 06/04/2015] [Accepted: 06/08/2015] [Indexed: 10/23/2022]
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16
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Edwards KL, Shultz S, Pilgrim M, Walker SL. Male reproductive success is correlated with testosterone in the eastern black rhinoceros (Diceros bicornis michaeli). Gen Comp Endocrinol 2015; 213:40-9. [PMID: 25562628 DOI: 10.1016/j.ygcen.2014.12.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 12/15/2014] [Accepted: 12/26/2014] [Indexed: 10/24/2022]
Abstract
Among natural populations of polygynous species, males often vary in their lifetime reproductive success. However, in managed populations of endangered species, either in situ or as part of captive breeding programmes, it is important to understand why differences in reproductive success occur. The European captive population of the critically endangered eastern black rhinoceros is currently under-performing relative to their wild counterparts, with low reproductive output and high reproductive skew limiting growth and genetic diversity. To investigate why over 40% of captive males fail to breed, faecal samples were collected weekly from 23 males at 12 institutions across Europe for 4-32 months. Testosterone metabolite concentration was compared between proven and non-proven males and a number of intrinsic and extrinsic factors that could influence reproductive success were also investigated. Males that sired within the last 3½ years had significantly higher androgen concentrations than non-proven males, and average testosterone was positively correlated with the number of offspring sired per year spent in the reproductive age class. Proven and non-proven males did not differ in their body condition, or in average faecal glucocorticoid concentration. Differences in individual temperament were associated with adrenal activity, but did not correlate with reproductive category. Highest testosterone concentrations were observed in proven males that were housed with females during oestrus, and lowest concentrations in non-proven females not housed with females at all during the study period. Further work is necessary to determine whether proven males had higher testosterone due to underlying differences associated with quality, or whether external stimuli such as access to females could influence testosterone concentration and increase a male's chances of becoming a successful breeder.
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Affiliation(s)
- Katie L Edwards
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK; North of England Zoological Society, Chester Zoo, Chester CH2 1LH, UK.
| | - Susanne Shultz
- Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Mark Pilgrim
- North of England Zoological Society, Chester Zoo, Chester CH2 1LH, UK
| | - Susan L Walker
- North of England Zoological Society, Chester Zoo, Chester CH2 1LH, UK
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Laidre KL, Born EW, Gurarie E, Wiig Ø, Dietz R, Stern H. Females roam while males patrol: divergence in breeding season movements of pack-ice polar bears (Ursus maritimus). Proc Biol Sci 2013; 280:20122371. [PMID: 23222446 PMCID: PMC3574305 DOI: 10.1098/rspb.2012.2371] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 11/09/2012] [Indexed: 11/12/2022] Open
Abstract
Intraspecific differences in movement behaviour reflect different tactics used by individuals or sexes to favour strategies that maximize fitness. We report movement data collected from n = 23 adult male polar bears with novel ear-attached transmitters in two separate pack ice subpopulations over five breeding seasons. We compared movements with n = 26 concurrently tagged adult females, and analysed velocities, movement tortuosity, range sizes and habitat selection with respect to sex, reproductive status and body mass. There were no differences in 4-day displacements or sea ice habitat selection for sex or population. By contrast, adult females in all years and both populations had significantly more linear movements and significantly larger breeding range sizes than males. We hypothesized that differences were related to encounter rates, and used observed movement metrics to parametrize a simulation model of male-male and male-female encounter. The simulation showed that the more tortuous movement of males leads to significantly longer times to male-male encounter, while having little impact on male-female encounter. By contrast, linear movements of females are consistent with a prioritized search for sparsely distributed prey. These results suggest a possible mechanism for explaining the smaller breeding range sizes of some solitary male carnivores compared to females.
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Affiliation(s)
- Kristin L Laidre
- Polar Science Center, APL, University of Washington, Seattle, WA 98105, USA.
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Metrione LC, Penfold LM, Waring GH. Social and spatial relationships in captive southern white rhinoceros (Ceratotherium simum simum). Zoo Biol 2012; 26:487-502. [PMID: 19360596 DOI: 10.1002/zoo.20143] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although critical to the conservation of white rhinoceros, captive breeding has proven challenging because of the poor and irregular reproductive health of many captive rhinos, and social interactions may play a significant role. This research investigated the social and spatial relationships of two captive groups of southern white rhinoceros (Ceratotherium simum simum) by examining the frequency of companion changes, the number of space maintenance vocalizations made per hour by each reproductively mature female, and dominant/subordinate interactions. The observed captive rhinos did not change their companionships during the study. They exhibited space maintenance vocalizations and display greater than once per hour, particularly when feeding. Females housed with four calves on 0.033 km(2) exhibited space maintenance vocalizations more frequently (X+/-SE = 6.19+/-0.199/hr) than females housed with one calf and more space (0.06 km(2), X+/-SE = 0.55+/-0.182/hr) and females housed without calves and more space (0.65 km(2), X+/-SE = 1.90+/-0.086/hr). Wider separation of food piles and of females with young calves is suggested to reduce the interpreted spatial stress. The presence of a large number of rhinos in restricted captive space resulted in the formation of herds with dominance hierarchies that were enforced during competition for food and shade. The most subordinate rhino in each of the herds exhibited unusual behaviors such as dung-kicking and nonestrus urine squirting, and neither has ever reproduced. Suppression of subordinate rhinos might lead to social stress that could negatively impact reproductive success. Zoo Biol 26:487-502, 2007. (c) 2007 Wiley-Liss, Inc.
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Guerier AS, Bishop JM, Crawford SJ, Schmidt-Küntzel A, Stratford KJ. Parentage analysis in a managed free ranging population of southern white rhinoceros: genetic diversity, pedigrees and management. CONSERV GENET 2012. [DOI: 10.1007/s10592-012-0331-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Linklater WL, MacDonald EA, Flamand JRB, Czekala NM. Declining and low fecal corticoids are associated with distress, not acclimation to stress, during the translocation of African rhinoceros. Anim Conserv 2010. [DOI: 10.1111/j.1469-1795.2009.00308.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Portas T, Johnston SD, Hermes R, Arroyo F, López-Fernadez C, Bryant B, Hildebrandt TB, Göritz F, Gosalvez J. Frozen-thawed rhinoceros sperm exhibit DNA damage shortly after thawing when assessed by the sperm chromatin dispersion assay. Theriogenology 2009; 72:711-20. [PMID: 19560805 DOI: 10.1016/j.theriogenology.2009.05.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2008] [Revised: 05/02/2009] [Accepted: 05/03/2009] [Indexed: 11/29/2022]
Abstract
This study reports on the successful validation (via in situ nick translation and neutral comet assay) of the equine Sperm-Halomax kit as an appropriate methodology for the assessment of sperm DNA fragmentation in three species of rhinoceros. Rhinoceros sperm nuclei with fragmented DNA (validated using in situ nick translation) were evident as large halos with dispersed DNA fragments, whereas those with nonfragmented DNA displayed small halos of nondispersed DNA within the microgel. There was a high correlation (r) of 0.974 (R(2) value=0.949; P<0.01; n=16) between the respective assessments of the Sperm Chromatin Dispersion test (SCDt) and the neutral comet assay. Application of the SCDt to determine the DNA fragmentation dynamics of rhinoceros (n=6) sperm frozen in liquid nitrogen vapor and incubated postthaw at 37 degrees C for up to 48 h to mimic in vitro conditions in the female reproductive tract, revealed an increase (P=0.001) in DNA damage, as soon as 4h after the start of incubation. Linear regression equations were calculated for all six rhinoceroses over the first 6h of incubation and revealed individual animal variation. Freshly collected and incubated (37 degrees C) rhinoceros (n=3) sperm had no increase in the basal level of DNA fragmentation for up to 48 h, indicating that the cryopreservation of rhinoceros sperm in liquid nitrogen vapor, as used in this study, appeared to result in freeze-thaw DNA damage.
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Affiliation(s)
- T Portas
- Taronga Western Plains Zoo, Dubbo, NSW 2830, Australia
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Effects of sociosexual environment on serum testosterone in captive male African rhinoceros. Theriogenology 2009; 71:1105-11. [DOI: 10.1016/j.theriogenology.2008.12.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2008] [Revised: 11/19/2008] [Accepted: 12/07/2008] [Indexed: 11/23/2022]
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Jacobs DF, Hernandez-Camacho CJ, Young JK, Gerber LR. Determinants of Outcomes of Agonistic Interactions among Male California Sea Lions (Zalophus californianus). J Mammal 2008. [DOI: 10.1644/07-mamm-a-171.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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SCHWARZENBERGER F. The many uses of non-invasive faecal steroid monitoring in zoo and wildlife species. ACTA ACUST UNITED AC 2007. [DOI: 10.1111/j.1748-1090.2007.00017.x] [Citation(s) in RCA: 148] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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White AM, Swaisgood RR, Czekala N. Differential Investment in Sons and Daughters: Do White Rhinoceros Mothers Favor Sons? J Mammal 2007. [DOI: 10.1644/06-mamm-a-180r2.1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Kretzschmar P, Ganslosser U, Dehnhard M. Relationship between androgens, environmental factors and reproductive behavior in male white rhinoceros (Ceratotherium simum simum). Horm Behav 2004; 45:1-9. [PMID: 14733886 DOI: 10.1016/j.yhbeh.2003.08.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We conducted a longitudinal study of the endocrine activity of free-range male white rhinos. An enzyme immunoassay to measure androgens in the feces was developed and validated to show that it can be used to study testicular activity. We identified two fecal metabolites similar to testosterone and dihydrotestosterone. Several lines of evidence suggest that these metabolites clearly reflect testicular activity. Firstly, the stimulation of testicular activity with synthetic GnRH caused a 156% increase in androgen metabolite concentrations in the feces 1 day after treatment. Secondly, androgen metabolite concentrations increased with sexual maturity in rhinos, and finally there was a correlation between testosterone concentrations in plasma and androgen metabolite concentrations in feces. Using the method that we developed, it was possible to establish whether a relationship exists between androgen metabolite concentrations, the behavior and environmental factors. Adult territorial males (n = 5) had elevated androgen metabolite concentrations during months of high rainfall (September-February) compared to months of little or no rainfall (March-August). The increase in concentrations coincided with the beginning of the rainy season, suggesting a seasonal trend in reproduction. This trend was confirmed by behavior observations showing both a higher frequency of conceptions within the first 4 months of increased androgen metabolite concentrations, and a higher number of inter-sexual conflicts, reflecting the initial aggression between the sexes during the consort period. It was also evident that males accompanying a receptive female had higher fecal androgen metabolite concentrations compared to being alone. The elevated levels were likely induced by female presence.
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Affiliation(s)
- Petra Kretzschmar
- Zoological Institute I, University Erlangen--Nürnberg, D-91058, Erlangen, Germany.
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Seror B, Zorovsky Y, Terkel A, Katcoff DJ. Genetic kinship and social structure in a herd of square-lipped rhinoceroses (Ceratotherium simum simum) at the zoological center, Tel Aviv/Ramat-Gan, Israel. Zoo Biol 2002. [DOI: 10.1002/zoo.10056] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Craig AS, Herman LM, Pack AA. Male mate choice and male-male competition coexist in the humpback whale (Megaptera novaeangliae). CAN J ZOOL 2002. [DOI: 10.1139/z02-050] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Male humpback whales (Megaptera novaeangliae) outnumber females on the winter grounds and compete physically for proximity to females. Analyses of identification photographs collected in Hawai'i from 1976 through 1995 and scan samples collected in 1998 showed that (i) reproductive potential (calving rate) for the following winter was greater for females without a calf than females with a calf, (ii) females without a calf were less likely to be found alone and more likely to be found in large pods than females with a calf, (iii) individual females were found in larger pods when without a calf than when with a calf, (iv) the probability of females with a calf being escorted by one or more males increased as the reproductive season progressed, and (v) head lunges occurred more commonly in all-adult pods than in pods containing a calf. We concluded that male humpback whales associate preferentially with females with high reproductive potential, that the attractiveness of individual females varies with their status (with a calf versus without a calf), that males become progressively less choosy over the course of the reproductive season as females without a calf become increasingly rare on the winter grounds, and that males expend more energy in competition over females without a calf than females with a calf.
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Abstract
Manes are generally thought to characterize all adult male lions (Panthera leo). Here we document a population of lions in Tsavo National Park, Kenya, that is largely maneless and describe aspects of their social organization. Because Tsavo's arid landscape supports sparse prey populations, we expected that surveys of lions there would document small social groups. We hypothesized that Tsavo lions would consequently experience reduced sexual selection pressures for mane development. Adult males from Tsavo typically have sparse blond hair forming a dorsal crest, beard, chest tufts, and (or) sideburns, but lack the large flowing manes reported from other lion populations. No fully maned lions were seen. Maneless males in Tsavo appear to be well integrated into pride life, and were observed copulating, hunting, and otherwise interacting with groups of females, playing with dependent cubs, and advertising territories with scent markings and roars. Only one adult male was observed in each of five prides, which differs surprisingly from the coalitions of 24 pride males noted in other lion groups. However, female group size was large (mean 7.4) and comparable with what has been documented in the Serengeti and elsewhere, refuting our "group size mane size" hypothesis. Future research should focus on the effect of Tsavo's physical and physiological effects on mane condition, and the possible correlation of male hormone levels with both manelessness and small male-group size.
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Rachlow JL, Kie JG, Berger J. Territoriality and spatial patterns of white rhinoceros in Matobo National Park, Zimbabwe. Afr J Ecol 2001. [DOI: 10.1046/j.1365-2028.1999.00175.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Abstract
Only approximately 2600 black rhinoceros survive today, mainly in small, isolated populations of < 100 animals. The management of remaining black rhinoceros populations aims at preserving natural levels of genetic relatedness and optimizing breeding success, which requires an accurate knowledge of the mating system, reproductive skew and effective population size. DNA was extracted from faecal samples from a community of 35 wild black rhinoceros, and microsatellites were used to characterize patterns of paternity of 19 offspring born from eight females in this community. Paternity could be ascribed unequivocally for each offspring. Although our conclusions must be considered tentative, we present the first genetic evidence that black rhinoceros males are polygynous, with a high variance in reproductive success. We also describe a noninvasive management tool that can be used for the genetic management of this critically endangered species, both in the wild and in captivity.
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Affiliation(s)
- J N Garnier
- Zoological Society of London, Regent's Park, London NW1 4RY, UK
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