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Correa LA, Aspillaga-Cid A, Bauer CM, Silva-Álvarez D, León C, Ramírez-Estrada J, Soto-Gamboa M, Hayes LD, Ebensperger LA. Social environment and anogenital distance length phenotype interact to explain testosterone levels in a communally rearing rodent: Part 1: The male side. Horm Behav 2024; 160:105479. [PMID: 38278060 DOI: 10.1016/j.yhbeh.2024.105479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 01/08/2024] [Accepted: 01/09/2024] [Indexed: 01/28/2024]
Abstract
In vertebrates, male testosterone levels vary across the year being generally higher during the mating season relative to the offspring rearing season. However, male testosterone levels may also be associated with male anogenital distance (AGD) length (a proxy of prenatal androgen exposition), and influenced by the social group environment. In social species, it has been proposed that high levels of testosterone could be incompatible with the development of an amicable social environment. Thus, in these species, it is predicted that males have relatively low levels of testosterone. Our goal was to examine the potential association between male serum testosterone levels, season, male AGD length, and the social environment in the rodent Octodon degus under natural conditions. We quantified male serum testosterone levels during the mating and offspring rearing seasons, and we determined the number of females and males in each social group, as well as the composition of groups, in terms of the AGD length of the female and male group mates, from 2009 to 2019. Our results revealed that male testosterone levels covary with season, being highest during the offspring rearing season. Additionally, male testosterone levels vary with male AGD length, and female and male social group environments. More importantly, male degus exhibit low levels of testosterone that are indistinguishable from female levels during offspring rearing season. Similar to other highly social mammals, where males and females live together year-round, male amicable behavior could be the best male mating strategy, thus leading to a reduction in circulating testosterone levels.
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Affiliation(s)
- Loreto A Correa
- Escuela de Medicina Veterinaria, Facultad de Medicina y Ciencias de la Salud, Universidad Mayor, Camino la Pirámide 5750, Huechuraba, Santiago, Chile.
| | - Antonia Aspillaga-Cid
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Carolyn M Bauer
- Department of Biology, Swarthmore College, Swarthmore, PA, USA
| | - Danna Silva-Álvarez
- Escuela de Medicina Veterinaria, Facultad de Medicina y Ciencias de la Salud, Universidad Mayor, Camino la Pirámide 5750, Huechuraba, Santiago, Chile
| | - Cecilia León
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Juan Ramírez-Estrada
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Mauricio Soto-Gamboa
- Laboratorio de Ecología Conductual y Conservación, Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - Loren D Hayes
- Department of Biology, Geology and Environmental Sciences, University of Tennessee at Chattanooga, Chattanooga, TN 37403, USA
| | - Luis A Ebensperger
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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2
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Correa LA, Aspillaga-Cid A, León C, Bauer CM, Ramírez-Estrada J, Hayes LD, Soto-Gamboa M, Ebensperger LA. Social environment and anogenital distance length phenotype interact to explain testosterone levels in a communally rearing rodent: Part 2: The female side. Horm Behav 2024; 160:105486. [PMID: 38295731 DOI: 10.1016/j.yhbeh.2024.105486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 01/09/2024] [Accepted: 01/12/2024] [Indexed: 03/26/2024]
Abstract
Testosterone is known as a "male" hormone; however, females also synthetize testosterone, which influences female sexual and aggressive behavior. In female vertebrates, as in males, testosterone levels can vary seasonally. However, female testosterone levels may also be related with female anogenital distance (AGD) length phenotype (a proxy of prenatal androgen exposure), and the social group environment. We used data from a long-term rodent study (2009-2019) in a natural population of degus (Octodon degus) to examine the potential associations between female serum testosterone levels, season, female AGD phenotype, and social group composition. We quantified female serum testosterone levels during the mating and offspring rearing seasons, and we determined the number of females and males in social groups, as well the composition of groups, in terms of the AGD of the female and male group mates. Our results indicate that female testosterone levels vary with season, being highest during the offspring rearing season. Additionally, female testosterone levels were associated with the number of male group-members and the AGD of male group-members but were not associated with female social environment and focal female AGD phenotype. Together, our results suggest that female testosterone levels are sensitive to intersexual interactions. Our results also reveal that female and male testosterone levels do not differ between the sexes, a finding previously reported only in rock hyraxes. We discuss how the complex social system of degus could be driving this physiological similarity between the sexes.
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Affiliation(s)
- Loreto A Correa
- Escuela de Medicina Veterinaria, Facultad de Medicina y Ciencias de la Salud, Universidad Mayor, Camino la Pirámide 5750, Huechuraba, Santiago, Chile.
| | - Antonia Aspillaga-Cid
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile
| | - Cecilia León
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile
| | - Carolyn M Bauer
- Department of Biology, Swarthmore College, Swarthmore, PA 19081, USA
| | - Juan Ramírez-Estrada
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile
| | - Loren D Hayes
- Department of Biology, Geology and Environmental Sciences, University of Tennessee at Chattanooga, Chattanooga, TN 37403, USA
| | - Mauricio Soto-Gamboa
- Laboratorio de Ecología Conductual y Conservación, Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - Luis A Ebensperger
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile
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3
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Correa LA, León C, Ramírez-Estrada J, Ly-Prieto Á, Abades S, Hayes LD, Soto-Gamboa M, Ebensperger LA. One for all and all for one: phenotype assortment and reproductive success in masculinized females. Behav Ecol 2021. [DOI: 10.1093/beheco/arab093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Abstract
Homophily by morphological and behavioral traits has been described in several species of vertebrates, but its functional consequences remain poorly studied. Homophily by plurally breeding females may improve direct fitness by enhancing reproductive success. Female mammals may exhibit phenotypical masculinization due to exposure to androgens during early development, a condition that is associated with maternal performance during subsequent breeding. Our goal was to assess whether female composition (in terms of masculinization) of plurally breeding groups influences female fitness in a natural population of degus (Octodon degus). We assessed if plurally breeding female degus assort themselves by anogenital distance (AGD), an accurate measure of masculinization level. We also quantified if homophily by AGD phenotype affects female reproductive success and the reproductive output of the group. Plurally breeding groups typically included similarly masculinized (i.e., long AGD) females or similarly feminized (short AGD) females, indicating a strong degree of homophily. Females weaned more offspring in plurally breeding groups with more masculinized females. Additionally, standardized variance in the number of offspring weaned decreased in plurally breeding groups with mostly masculinized females, indicating greater reproductive equality in these groups. We conclude that female degus organize into homophilic social groups of similar AGD, and that social groups of masculinized females exhibit a higher reproductive success.
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Affiliation(s)
- Loreto A Correa
- Escuela de Medicina Veterinaria, Facultad de Ciencias, Universidad Mayor, Camino la Pirámide, Huechuraba, Santiago, Chile
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla, Avenida Bernardo O’Higgins, Santiago, Chile
| | - Cecilia León
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla, Avenida Bernardo O’Higgins, Santiago, Chile
| | - Juan Ramírez-Estrada
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla, Avenida Bernardo O’Higgins, Santiago, Chile
| | - Álvaro Ly-Prieto
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla, Avenida Bernardo O’Higgins, Santiago, Chile
| | - Sebastián Abades
- GEMA Center for Genomics, Ecology & Environment, Faculty of Interdisciplinary Studies, Universidad Mayor, Camino La Pirámide, Huechuraba, Santiago, Chile
| | - Loren D Hayes
- Department of Biology, Geology and Environmental Sciences, University of Tennessee at Chattanooga, Chattanooga, TN, USA
| | - Mauricio Soto-Gamboa
- Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Casilla, Isla Teja s/n, Valdivia, Chile
| | - Luis A Ebensperger
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla, Avenida Bernardo O’Higgins, Santiago, Chile
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4
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Socioecological conditions predict degu social instability and provide limited cues to forecast subsequent breeding conditions. Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-03017-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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5
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Centeno-Cuadros A, Román J, Sánchez-Recuero A, Lucena-Pérez M, Delibes M, Godoy JA. Mating System, Breeding Success, and Pup Mortality of a Habitat Specialist Rodent: A Field and Molecular-based Approach. J MAMM EVOL 2021. [DOI: 10.1007/s10914-021-09542-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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6
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Perret M. Litter sex composition influences competitive performance during first reproduction in male mouse lemurs. Physiol Behav 2020; 228:113196. [PMID: 33017603 DOI: 10.1016/j.physbeh.2020.113196] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 09/30/2020] [Accepted: 10/01/2020] [Indexed: 11/25/2022]
Abstract
In litter-bearing mammals, conditions experienced early in life can have long-lasting consequences on adult behavioral and physiological phenotypes, including reproductive fitness and survival. Using data from a large database, we focused our analysis on the consequences of litter composition on the reproductive performance of 131 mouse lemur males during their first breeding season. For male offspring, body mass at birth and at weaning only depended on the litter size (from one to 3), with the lowest values in triplets. Early growth had no relationship with the future reproductive success when males entered their first breeding season. When mouse lemurs were kept in groups with 2 or 3 competitors, males entered sexual competition for priority access to females in estrus, leading to a hierarchy with the dominant male ensuring the successful mating of the females. Genetic paternity tests showed that males born in same-sex litters (M, MM, MMM) were more competitive and fathered more offspring than males born in mixed-sex litters (MF, MMF, MFF), indicating the negative impact of a sister on male reproductive success. However, testosterone levels were unrelated to early growth or litter sex composition but were dependent on social interactions during sexual competition, with higher values in successful males. The effects of litter composition on the mating success of male mouse lemurs might mainly occur through social interactions between male offspring born in same-sex litters. Play fighting between juvenile males could play a major role in their acquisition of the skills required to succeed in sexual competition.
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Affiliation(s)
- Martine Perret
- UMR Mecadev 7179 CNRS-MNHN, Département Adaptations du Vivant, 1 avenue du petit château, 91800 Brunoy, France.
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7
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Female–female mounting in pumas. J ETHOL 2020. [DOI: 10.1007/s10164-020-00658-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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8
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Perret M. Litter sex composition affects first reproduction in female grey mouse lemurs (Microcebus murinus). Physiol Behav 2019; 208:112575. [DOI: 10.1016/j.physbeh.2019.112575] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 06/05/2019] [Accepted: 06/05/2019] [Indexed: 01/25/2023]
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9
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Bauer CM, Correa LA, Ebensperger LA, Romero LM. Stress, sleep, and sex: A review of endocrinological research in Octodon degus. Gen Comp Endocrinol 2019; 273:11-19. [PMID: 29545088 DOI: 10.1016/j.ygcen.2018.03.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Revised: 02/20/2018] [Accepted: 03/11/2018] [Indexed: 10/17/2022]
Abstract
The Common Degu (Octodon degus) is a small rodent endemic to central Chile. It has become an important model for comparative vertebrate endocrinology because of several uncommon life-history features - it is diurnal, shows a high degree of sociality, practices plural breeding with multiple females sharing natal burrows, practices communal parental care, and can easily be studied in the laboratory and the field. Many studies have exploited these features to make contributions to comparative endocrinology. This review summarizes contributions in four major areas. First are studies on degu stress responses, focusing on seasonal changes in glucocorticoid (GC) release, impacts of parental care on offspring GC responses, and fitness consequences of individual variations of GC responses. These studies have helped confirm the ecological relevance of stress responses. Second are studies exploring diurnal circadian rhythms of melatonin and sex steroids. These studies have formed important work translating circadian biology from nocturnal laboratory rodents to diurnal humans. Third are studies that exploit the open nature of degu natural habitat, combined with laboratory studies, to explore the impact of testosterone on agonistic behavior. Studies have focused primarily on male:male, female:female, male:female, and parental behaviors. Fourth, are contributions to the study of female masculinization from male siblings in the uterus. These studies have focused on both the behavioral consequences of masculinization and the impact of those behaviors on fitness. Taken together, the studies reviewed here have formed a strong foundation for further studies in the degu so that future studies can address how endocrinological components underlie new mechanistic connections to the ecological effects on behavior and fitness.
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Affiliation(s)
- Carolyn M Bauer
- Biology Department, Adelphi University, Garden City, NY, USA.
| | - Loreto A Correa
- Escuela de Medicina Veterinaria, Facultad de Ciencias, Universidad Mayor, Santiago, Chile; Departamento de Ecología, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago, Chile
| | - Luis A Ebensperger
- Departamento de Ecología, Facultad de Ciencias Biológicas, P. Universidad Católica de Chile, Santiago, Chile
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10
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Correa LA, León C, Ramírez-Estrada J, Ly-Prieto Á, Abades S, Hayes LD, Soto-Gamboa M, Ebensperger LA. Highly masculinized and younger males attain higher reproductive success in a social rodent. Behav Ecol 2018. [DOI: 10.1093/beheco/ary015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Affiliation(s)
- Loreto A Correa
- Núcleo Interdisciplinario, Escuela de Medicina Veterinaria, Facultad de Ciencias. Universidad Mayor, Camino la Pirámide, Huechuraba, Santiago, Chile
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla, Santiago, Chile
| | - Cecilia León
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla, Santiago, Chile
| | - Juan Ramírez-Estrada
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla, Santiago, Chile
| | - Álvaro Ly-Prieto
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla, Santiago, Chile
| | - Sebastián Abades
- GEMA Center for Genomics, Ecology & Environment, Universidad Mayor, Camino La Pirámide, Huechuraba, Santiago, Chile
| | - Loren D Hayes
- Department of Biology, Geology and Environmental Sciences, University of Tennessee at Chattanooga, Chattanooga, TN, USA
| | - Mauricio Soto-Gamboa
- Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Casilla, Valdivia, Chile
| | - Luis A Ebensperger
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla, Santiago, Chile
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11
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Altimiras F, Uszczynska-Ratajczak B, Camara F, Vlasova A, Palumbo E, Newhouse S, Deacon RMJ, Farias LAE, Hurley MJ, Loyola DE, Vásquez RA, Dobson R, Guigó R, Cogram P. Brain Transcriptome Sequencing of a Natural Model of Alzheimer's Disease. Front Aging Neurosci 2017; 9:64. [PMID: 28373841 PMCID: PMC5357652 DOI: 10.3389/fnagi.2017.00064] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 03/01/2017] [Indexed: 12/31/2022] Open
Affiliation(s)
- Francisco Altimiras
- Faculty of Engineering and Sciences, Universidad Adolfo IbañezSantiago, Chile
- Telefonica Research and DevelopmentSantiago, Chile
| | - Barbara Uszczynska-Ratajczak
- Centre for Genomic Regulation, Barcelona Institute of Science and TechnologyBarcelona, Spain
- Universitat Pompeu FabraBarcelona, Spain
| | - Francisco Camara
- Centre for Genomic Regulation, Barcelona Institute of Science and TechnologyBarcelona, Spain
- Universitat Pompeu FabraBarcelona, Spain
| | - Anna Vlasova
- Centre for Genomic Regulation, Barcelona Institute of Science and TechnologyBarcelona, Spain
- Universitat Pompeu FabraBarcelona, Spain
| | - Emilio Palumbo
- Centre for Genomic Regulation, Barcelona Institute of Science and TechnologyBarcelona, Spain
- Universitat Pompeu FabraBarcelona, Spain
| | - Stephen Newhouse
- Institute of Psychiatry, Psychology and Neuroscience, King's College LondonLondon, UK
| | - Robert M. J. Deacon
- Laboratory of Molecular Neuropsychiatry, Institute of Cognitive and Translational Neuroscience (INCyT), INECO Foundation, Favaloro University, National Scientific and Technical Research CouncilBuenos Aires, Argentina
- GeN.DDI LtdLondon, UK
| | | | - Michael J. Hurley
- Division of Brain Sciences, Centre for Neuroinflammation and Neurodegeneration, Imperial CollegeLondon, UK
| | - David E. Loyola
- National Center for Genomics and BioinformaticsSantiago, Chile
| | - Rodrigo A. Vásquez
- Faculty of Sciences, Institute of Ecology and Biodiversity, Universidad de ChileSantiago, Chile
| | - Richard Dobson
- Institute of Psychiatry, Psychology and Neuroscience, King's College LondonLondon, UK
| | - Roderic Guigó
- Centre for Genomic Regulation, Barcelona Institute of Science and TechnologyBarcelona, Spain
- Universitat Pompeu FabraBarcelona, Spain
| | - Patricia Cogram
- Laboratory of Molecular Neuropsychiatry, Institute of Cognitive and Translational Neuroscience (INCyT), INECO Foundation, Favaloro University, National Scientific and Technical Research CouncilBuenos Aires, Argentina
- GeN.DDI LtdLondon, UK
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12
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Chock RY, Wey TW, Ebensperger LA, Hayes L. Evidence for a behavioural syndrome and negative social assortment by exploratory personality in the communally nesting rodent, Octodon degus. BEHAVIOUR 2017. [DOI: 10.1163/1568539x-00003433] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Recent research in behavioural ecology has revealed the structure of animal personality and connections to ecologically and evolutionarily important traits. Personality is hypothesized to influence social interactions through individual behavioural differences or personality-based dyadic interactions. We describe the structure of personality traits and ask if two traits, boldness and exploration, play a role in the strength or pattern of social associations in a wild population of degus, a rodent that often lives communally with unrelated conspecifics. Boldness was repeatable in both adults and juveniles, but exploration was only repeatable in adults. We found evidence for a behavioural syndrome between exploration and boldness in adult degus. We documented negative assortment by exploratory personality type; more exploratory animals shared burrows with less exploratory animals. However, tendency towards boldness and exploration were not predictive of association strength. Our results highlight a potential connection between personality and social structure in a communally nesting species.
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Affiliation(s)
- Rachel Y. Chock
- Department of Ecology and Evolutionary Biology, University of California, 612 Charles E. Young Dr. East, Los Angeles, CA 90095-7246, USA
| | - Tina W. Wey
- Département des sciences biologiques, Université du Québec à Montréal, Montréal, QC, Canada H3C 3P8
| | - Luis A. Ebensperger
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Loren D. Hayes
- Department of Biology, Geology, and Environmental Sciences, University of Tennessee at Chattanooga, Chattanooga, TN 37403, USA
- Department of Biology, University of Louisiana at Monroe, Monroe, LA 71203, USA
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