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Sobral G, Dubuc C, Winters S, Ruiz-Lambides A, Emery Thompson M, Maestripieri D, Milich KM. Facial and genital color ornamentation, testosterone, and reproductive output in high-ranking male rhesus macaques. Sci Rep 2024; 14:2621. [PMID: 38297064 PMCID: PMC10831099 DOI: 10.1038/s41598-024-52400-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 01/18/2024] [Indexed: 02/02/2024] Open
Abstract
Males in many vertebrate species have colorful ornaments that evolved by sexual selection. The role of androgens in the genesis and maintenance of these signals is unclear. We studied 21 adult high-ranking male rhesus macaques from nine social groups in the free-ranging population on Cayo Santiago, Puerto Rico, and analyzed facial and genital skin luminance and redness, fecal androgens, rates of mating behaviors, and offspring sired. Facial and genital coloration varied in relation to age, mating behavior, reproductive success, and testosterone concentration. Our results indicate that skin coloration in high-ranking male rhesus macaques is a sexually-selected trait mediated by androgens. These results add to the growing literature on the proximate and ultimate causes of male sexual signals and highlight the need to examine how these characteristics change with age in other species.
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Affiliation(s)
- Gisela Sobral
- Department of Anthropology, Washington University in St. Louis, St. Louis, MO, USA
- Instituto de Biodiversidade e Sustentabilidade (NUPEM/UFRJ), Macaé, RJ, Brazil
| | - Constance Dubuc
- Department of Anthropology, New York University, New York, NY, USA
| | - Sandra Winters
- Department of Anthropology, New York University, New York, NY, USA
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | | | | | | | - Krista M Milich
- Department of Anthropology, Washington University in St. Louis, St. Louis, MO, USA.
- Institute for Mind and Biology, University of Chicago, Chicago, IL, USA.
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Greenberg D, Snyder KP, Filazzola A, Mastromonaco GF, Schoof VAM. Hormonal correlates of male dominance rank, age, and genital colouration in vervet monkey (Chlorocebus pygerythrus). Gen Comp Endocrinol 2022; 316:113948. [PMID: 34826430 DOI: 10.1016/j.ygcen.2021.113948] [Citation(s) in RCA: 2] [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: 05/30/2021] [Revised: 11/02/2021] [Accepted: 11/19/2021] [Indexed: 01/04/2023]
Abstract
Primates are the most colourful members of the Mammalian clade. In vervet monkeys (Chlorocebus pygerythrus), males are characterized by their red penis and blue scrotum. Such colour signals are often used in conspecific communication, and thus could be used to convey signaller condition. We quantified scrotal and penile colour characteristics using digital photographs between May-June 2016 from males in two neighboring groups along the shores of Lake Nabugabo, Uganda. We examined the relationship between fecal hormones, male dominance rank, age (adult vs. immature), and colour. Adult males were higher ranking than immatures, but there were no rank or age differences in fecal hormone levels. Glucocorticoids and androgens were positively correlated in immature, but not adult males. All scrotal characteristics were predicted by age, with adult males having more teal (i.e., less blue, more green) and more luminant scrota. Within adult males, those with higher androgens levels had more saturated blue scrotal colouration and higher-ranking males were more luminant. Penile colouration was also associated with age and rank. High-ranking males had a more saturated red penis, and adult male penile colour was more luminant and bluer than in immature males. Our findings are consistent with previous reports that scrotal colouration advertises sexual or reproductive maturity (i.e., age), but we also find that within adult males, colour also advertises dominance rank and may be mediated by androgen levels. Penile colouration also appears to signal information about male age and dominance rank but does not appear to be mediated by hormones.
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Affiliation(s)
- D Greenberg
- Department of Biology, Faculty of Science, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
| | - K P Snyder
- Department of Biology, Faculty of Science, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
| | - A Filazzola
- Department of Biology, Faculty of Science, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada; Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON M1C 1A4, Canada
| | - G F Mastromonaco
- Reproductive Sciences Unit, Toronto Zoo, 361A Old Finch Avenue, Toronto, ON M1B 5K7, Canada
| | - V A M Schoof
- Department of Biology, Faculty of Science, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada; Bilingual Biology Program, Department of Multidisciplinary Studies, Glendon College, York University, 2275 Bayview Avenue, Toronto, ON M4N 3M6, Canada.
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Caro T, Stankowich T. A roadmap for comparative primate coloration research: a response to comments on Caro et al. Behav Ecol 2021. [DOI: 10.1093/beheco/arab075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Tim Caro
- School of Biological Sciences, University of Bristol, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
- Center for Population Biology, University of California, 1 Shields Avenue, Davis, CA 95616, USA
| | - Theodore Stankowich
- Department of Biological Sciences, California State University, 1250 Bellflower Boulevard, Long Beach, CA 90840, USA
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Alempijevic D, Boliabo EM, Coates KF, Hart TB, Hart JA, Detwiler KM. A natural history of Chlorocebus dryas from camera traps in Lomami National Park and its buffer zone, Democratic Republic of the Congo, with notes on the species status of Cercopithecus salongo. Am J Primatol 2021; 83:e23261. [PMID: 33956342 DOI: 10.1002/ajp.23261] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 04/01/2021] [Accepted: 04/06/2021] [Indexed: 02/06/2023]
Abstract
The natural history and taxonomic status of two central African primates, Cercopithecus dryas and Cercopithecus salongo have long been in question. Recent studies confirmed that C. dryas is a basal member of the savanna monkey clade, and that it prefers dense undergrowth in lowland rainforest. While these studies advanced our knowledge of this enigmatic species, key aspects of its natural history remain poorly documented. Furthermore, the lack of a field study that documents pelage patterns of both sexes and different age classes of C. dryas has led to a disagreement over the validity of C. salongo as a sister taxon to C. dryas. Using the results of two multi-strata camera trap surveys in Lomami National Park (Democratic Republic of the Congo) and its buffer zone, we conducted a third survey in the understory of degraded forest to accumulate videos of C. dryas/salongo. We used these videos to test the hypothesis that C. dryas and C. salongo are synonymous, and to assess the species' group composition, density, behavior and vocalizations. Camera traps revealed an ontogenetic change in pelage pattern that supports the view that C. salongo is the adult of C. dryas. Videos revealed that adult males develop a blue perineum and scrotum, and a red subcaudal patch, similar to other savanna monkeys. We provide a preliminary assessment of C. dryas' group composition, density, behavior, and vocalizations. This long-overlooked monkey is an exceptional member of the Chlorocebus clade, and all aspects of its biology require further investigation.
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Affiliation(s)
- Daniel Alempijevic
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida, USA
| | - Ephrem M Boliabo
- Frankfurt Zoological Society, Kinshasa, Democratic Republic of the Congo
| | - Kathryn F Coates
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida, USA
| | - Terese B Hart
- Frankfurt Zoological Society, Kinshasa, Democratic Republic of the Congo
| | - John A Hart
- Frankfurt Zoological Society, Kinshasa, Democratic Republic of the Congo
| | - Kate M Detwiler
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, Florida, USA.,Department of Anthropology, Florida Atlantic University, Boca Raton, Florida, USA
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