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Correa LA, Aspillaga-Cid A, Riquelme J, Ly-Prieto Á, Hayes LD, Ebensperger LA. Activational and organizational effects of testosterone on the number of mating partners and reproductive success in males of a social rodent. Horm Behav 2024; 165:105613. [PMID: 39121710 DOI: 10.1016/j.yhbeh.2024.105613] [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: 04/30/2024] [Revised: 07/08/2024] [Accepted: 07/27/2024] [Indexed: 08/12/2024]
Abstract
The timing of exposure to the steroid hormone, testosterone, produces activational and organizational effects in vertebrates. These activational and organizational effects are hypothesized to relate with the number of female mating partners and reproductive success in males. We tested this hypothesis by examining 151 wild degu (Octodon degus) males across a 10-year study. We quantified the association between adult serum testosterone levels (i.e., an indirect index of adult activational effects) and anogenital distance (AGD) length (i.e., a direct index of fetal organizational effects), and their interaction on the number of female mating partners and reproductive success. We found no evidence of an association between adult male serum testosterone levels and the number of female mating partners, or between adult male serum testosterone levels and reproductive success. However, male AGD was positively associated with reproductive success, but not so with the number of female mating partners. Additionally, the positive association between male AGD and male reproductive success was mediated by the number of mates. Our findings do not support major roles of activational or organizational effects of testosterone on the number of female mating partners and its consequences on male reproductive success. Instead, our results suggest that compared with individual male attributes, the female social environment plays a more important role in driving male reproductive success.
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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
| | - Juan Riquelme
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile
| | - Álvaro Ly-Prieto
- 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
| | - Luis A Ebensperger
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile
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2
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Becerra F, Buezas GN, Cisilino A, Vassallo AI. Bite hard: Linking cranial loading mechanics to ecological differences in gnawing behavior in caviomorph rodents. J Anat 2024. [PMID: 39086103 DOI: 10.1111/joa.14117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 07/10/2024] [Accepted: 07/15/2024] [Indexed: 08/02/2024] Open
Abstract
The mammalian skull is very malleable and has notably radiated into highly diverse morphologies, fulfilling a broad range of functional needs. Although gnawing is relatively common in mammals, this behavior and its associated morphology are diagnostic features for rodents. These animals possess a very versatile and highly mechanically advantageous masticatory apparatus, which, for instance, allowed caviomorph rodents to colonize South America during the Mid-Eocene and successfully radiate in over 200 extant species throughout most continental niches. Previous work has shown that differences in bite force within caviomorphs could be better explained by changes in muscle development than in mechanical advantages (i.e., in cranial overall morphology). Considering the strong bites they apply, it is interesting to assess how the reaction forces upon the incisors (compression) and the powerful adductor musculature pulling (tension) mechanically affect the cranium, especially between species with different ecologies (e.g., chisel-tooth digging). Thus, we ran finite element analyses upon crania of the subterranean Talas' tuco-tuco Ctenomys talarum, the semi-fossorial common degu Octodon degus, and the saxicolous long-tailed chinchilla Chinchilla lanigera to simulate: (A) in vivo biting in all species, and (B) rescaled muscle forces in non-ctenomyid rodents to match those of the tuco-tuco. Results show that the stress patterns correlate with the mechanical demands of distinctive ecologies, on in vivo-based simulations, with the subterranean tuco-tuco being the most stressed species. In contrast, when standardizing all three species (rescaled models), non-ctenomyid models exhibited a several-fold increase in stress, in both magnitude and affected areas. Detailed observations evidenced that this increase in stress was higher in lateral sections of the snout and, mainly, the zygomatic arch; between approximately 2.5-3.5 times in the common degu and 4.0-5.0 times in the long-tailed chinchilla. Yet, neither species, module, nor simulation condition presented load factor levels that would imply structural failure by strong, incidental biting. Our results let us conclude that caviomorphs have a high baseline for mechanical strength of the cranium because of the inheritance of a very robust "rodent" model, while interspecific differences are associated with particular masticatory habits and the concomitant level of development of the adductor musculature. Especially, the masseteric and zygomaticomandibular muscles contribute to >80% of the bite force, and therefore, their contraction is responsible for the highest strains upon their origin sites, that is, the zygomatic arch and the snout. Thus, the robust crania of the subterranean and highly aggressive tuco-tucos allow them to withstand much stronger forces than degus or chinchillas, such as the ones produced by their hypertrophied jaw adductor muscles or imparted by the soil reaction.
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Affiliation(s)
- Federico Becerra
- Laboratorio de Morfología Funcional y Comportamiento, Instituto de Investigaciones Marinas y Costeras (Universidad Nacional Mar del Plata-Consejo Nacional de Investigaciones Científicas y Técnicas), Mar Del Plata, Argentina
| | - Guido Nicolás Buezas
- Instituto de Investigaciones Marinas y Costeras (Universidad Nacional de Mar del Plata-Consejo Nacional de Investigaciones Científicas y Técnicas), Mar Del Plata, Argentina
| | - Adrián Cisilino
- División Mecánica de Materiales, Instituto de Investigaciones en Ciencia y Tecnología de Materiales (Universidad Nacional de Mar del Plata-Consejo Nacional de Investigaciones Científicas y Técnicas), Mar Del Plata, Argentina
| | - Aldo Iván Vassallo
- Laboratorio de Morfología Funcional y Comportamiento, Instituto de Investigaciones Marinas y Costeras (Universidad Nacional Mar del Plata-Consejo Nacional de Investigaciones Científicas y Técnicas), Mar Del Plata, Argentina
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3
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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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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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Garduño BM, Hanni P, Hays C, Cogram P, Insel N, Xu X. How the forebrain transitions to adulthood: developmental plasticity markers in a long-lived rodent reveal region diversity and the uniqueness of adolescence. Front Neurosci 2024; 18:1365737. [PMID: 38456144 PMCID: PMC10917993 DOI: 10.3389/fnins.2024.1365737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 02/02/2024] [Indexed: 03/09/2024] Open
Abstract
Maturation of the forebrain involves transitions from higher to lower levels of synaptic plasticity. The timecourse of these changes likely differs between regions, with the stabilization of some networks scaffolding the development of others. To gain better insight into neuroplasticity changes associated with maturation to adulthood, we examined the distribution of two molecular markers for developmental plasticity. We conducted the examination on male and female degus (Octodon degus), a rodent species with a relatively long developmental timecourse that offers a promising model for studying both development and age-related neuropathology. Immunofluorescent staining was used to measure perineuronal nets (PNNs), an extracellular matrix structure that emerges during the closure of critical plasticity periods, as well as microglia, resident immune cells that play a crucial role in synapse remodeling during development. PNNs (putatively restricting plasticity) were found to be higher in non-juvenile (>3 month) degus, while levels of microglia (putatively mediating plasticity) decreased across ages more gradually, and with varying timecourses between regions. Degus also showed notable variation in PNN levels between cortical layers and hippocampal subdivisions that have not been previously reported in other species. These results offer a glimpse into neuroplasticity changes occurring during degu maturation and highlight adolescence as a unique phase of neuroplasticity, in which PNNs have been established but microglia remain relatively high.
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Affiliation(s)
- B. Maximiliano Garduño
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Patrick Hanni
- Department of Psychology, University of Montana, Missoula, MT, United States
| | - Chelsea Hays
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Patricia Cogram
- Department of Ecological Sciences, Faculty of Sciences, Institute of Ecology and Biodiversity, Universidad de Chile, Santiago, Chile
- The Center for Neural Circuit Mapping, University of California, Irvine, Irvine, CA, United States
| | - Nathan Insel
- Department of Psychology, University of Montana, Missoula, MT, United States
- Department of Psychology, Wilfrid Laurier University, Waterloo, ON, Canada
| | - Xiangmin Xu
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, Irvine, CA, United States
- The Center for Neural Circuit Mapping, University of California, Irvine, Irvine, CA, United States
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA, United States
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Popović N, Baño-Otalora B, Rol MÁ, Venero C, Madrid JA, Popović M. Effects of long-term individual housing of middle-aged female Octodon degus on spatial learning and memory in the Barnes maze task. Front Behav Neurosci 2023; 17:1221090. [PMID: 37600762 PMCID: PMC10435294 DOI: 10.3389/fnbeh.2023.1221090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Accepted: 07/18/2023] [Indexed: 08/22/2023] Open
Abstract
Introduction Prolonged social isolation is a form of passive chronic stress that has consequences on human and animal behavior. The present study was undertaken to elucidate whether the long-term isolation would precipitate age-related changes in anxiety and spatial learning and memory in degus. Methods We investigated the effects of long-term social isolation on anxiety levels in the light-dark test, and spatial orientation abilities in the Barnes maze. Middle-aged female Octodon degus were allocated to either group-housed (3 animals per cage) or individually-housed for 5 months. Results Under this experimental condition, there were no significant group differences in the anxiety level tested in the light-dark test and in the motivation to escape from the Barnes maze. There were no significant differences in cortisol levels between individually- and group-housed animals. On the last acquisition training day of spatial learning, individually- housed animals had a significantly higher number of correct responses and a smaller number of reference and working memory errors than the group-housed animals. In addition, isolated animals showed a tendency for reference and working memory impairment on the retention trial, while group-housed degus showed improvement in these parameters. Discussion and conclusion The present study indicates that prolonged social isolation during adulthood in female degus has a dual effect on spatial orientation. Specifically, it results in a significant improvement in acquisition skills but a slight impairment in memory retention. The obtained cognitive changes were not accompanied by modification in anxiety and cortisol levels.
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Affiliation(s)
- Natalija Popović
- Department of Human Anatomy and Psychobiology, Faculty of Medicine, University of Murcia, Murcia, Spain
- Biomedical Research Institute of Murcia, Virgen de la Arrixaca University Hospital, University of Murcia, Murcia, Spain
| | - Beatriz Baño-Otalora
- Chronobiology Lab, Department of Physiology, Faculty of Biology, University of Murcia, Mare Nostrum Campus, Instituto Universitario de Investigación en Envejecimiento, Murcia, Spain
| | - María Ángeles Rol
- Biomedical Research Institute of Murcia, Virgen de la Arrixaca University Hospital, University of Murcia, Murcia, Spain
- Chronobiology Lab, Department of Physiology, Faculty of Biology, University of Murcia, Mare Nostrum Campus, Instituto Universitario de Investigación en Envejecimiento, Murcia, Spain
- Ciber Fragilidad y Envejecimiento Saludable, Madrid, Spain
| | - César Venero
- Department of Psychobiology, Universidad Nacional de Educación a Distancia, Madrid, Spain
- Instituto Mixto de Investigación–Escuela Nacional de Sanidad, Madrid, Spain
| | - Juan Antonio Madrid
- Biomedical Research Institute of Murcia, Virgen de la Arrixaca University Hospital, University of Murcia, Murcia, Spain
- Chronobiology Lab, Department of Physiology, Faculty of Biology, University of Murcia, Mare Nostrum Campus, Instituto Universitario de Investigación en Envejecimiento, Murcia, Spain
- Ciber Fragilidad y Envejecimiento Saludable, Madrid, Spain
| | - Miroljub Popović
- Department of Human Anatomy and Psychobiology, Faculty of Medicine, University of Murcia, Murcia, Spain
- Biomedical Research Institute of Murcia, Virgen de la Arrixaca University Hospital, University of Murcia, Murcia, Spain
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7
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Ukyo R, Shinohara A, Koshimoto C, Nagura-Kato GA, Ieiri S, Tsuzuki Y, Sakamoto SH. Long-term behavioral effects of social separation during early life in a social mammal, Octodon degus. Sci Rep 2023; 13:9518. [PMID: 37308511 DOI: 10.1038/s41598-023-36745-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 06/08/2023] [Indexed: 06/14/2023] Open
Abstract
Social separation is thought to induce a strong stress response in social juvenile mammals, but little is known about how this response might vary throughout the development. The present study examines the long-term effects of early-life stress (ELS) induced by social separation on individual behaviors later in life using the social and precocious species Octodon degus. Four experimental groups were established a positive control group of mothers and siblings from six litters comprised the socially housed (SH) group, while pups from seven litters were randomly assigned to three treatments: pups experiencing no separation (NS) treatment while their siblings did; repeated bouts of consecutive separation (CS); intermittent separation (IS). We analyzed the effects of separation treatment on the frequency and duration of freezing, rearing and grooming behaviors. ELS was correlated with higher hyperactivity, and hyperactivity increased with more frequent separation. However, the behavioral trend of the NS group changed to hyperactive in long-term observation. The findings suggest that the NS group was indirectly affected by ELS. In addition, suggesting ELS acts to converge an individual's behavioral tendencies in a certain direction.
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Affiliation(s)
- Rina Ukyo
- Interdisciplinary Graduate School of Agriculture and Engineering, University of Miyazaki, Miyazaki, Japan
| | - Akio Shinohara
- Division of Bio-Resources, Department of Biotechnology, Frontier Science Research Center, University of Miyazaki, 5200 Kihara, Kiyotake-cho, Miyazaki-shi, Miyazaki, 889-1692, Japan
| | - Chihiro Koshimoto
- Division of Bio-Resources, Department of Biotechnology, Frontier Science Research Center, University of Miyazaki, 5200 Kihara, Kiyotake-cho, Miyazaki-shi, Miyazaki, 889-1692, Japan
| | - Goro A Nagura-Kato
- Division of Bio-Resources, Department of Biotechnology, Frontier Science Research Center, University of Miyazaki, 5200 Kihara, Kiyotake-cho, Miyazaki-shi, Miyazaki, 889-1692, Japan
| | - Seiji Ieiri
- Faculty of Agriculture, University of Miyazaki, Miyazaki, 889-2192, Japan
| | - Yasuhiro Tsuzuki
- Faculty of Agriculture, University of Miyazaki, Miyazaki, 889-2192, Japan
| | - Shinsuke H Sakamoto
- Faculty of Agriculture, University of Miyazaki, Miyazaki, 889-2192, Japan.
- Center for Animal Disease Control, University of Miyazaki, Miyazaki, Japan.
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Nespolo RF, Peña I, Mejías C, Ñunque A, Altamirano T, Bozinovic FF. Communal nesting is the optimal strategy for heat conservation in a social marsupial: lessons from biophysical models. J Exp Biol 2022; 225:284634. [PMID: 36420835 PMCID: PMC9720746 DOI: 10.1242/jeb.244606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 11/07/2022] [Indexed: 11/25/2022]
Abstract
Endothermy, understood as the maintenance of continuous and high body temperatures owing to the combination of metabolic heat production and an insulative cover, is severely challenged in small endotherms inhabiting cold environments. As a response, social clustering combined with nest use (=communal nesting) is a common strategy for heat conservation. To quantify the actual amount of energy that is saved by this strategy, we studied the social marsupial Dromiciops gliroides (monito del monte), an endemic species of the cold forests of southern South America. It is hypothesized that sociability in this marsupial was driven by cold conditions, but evidence supporting this hypothesis is unclear. Here, we used taxidermic models ('mannequins') to experimentally test the energetic benefits of clustering combined with nest use. To do this, we fitted and compared cooling curves of solitary and grouped mannequins, within and outside of a nest, at the typical winter ambient temperatures of their habitat (5°C). We found that the strategy that minimized euthermic cost of maintenance was the combination of nest use and clustering, thus supporting communal nesting as a social adaptation to cope with the cold. Considering the basal metabolic rate of monitos, our estimates suggest that the savings represents almost half of energy consumption per day (in resting conditions). This study shows how simple biophysical models could help to evaluate bioenergetic hypotheses for social behavior in cold-adapted endotherms.
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Affiliation(s)
- Roberto F. Nespolo
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile,Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile,Center of Applied Ecology and Sustainability (CAPES), Pontificia Universidad Católica de Chile, Santiago, Chile,Millennium Nucleus of Patagonian Limit of Life (LiLi), Valdivia, Chile,Author for correspondence ()
| | - Isabella Peña
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile
| | - Carlos Mejías
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile,Magister en Ecología Aplicada, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - Abel Ñunque
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile,Millennium Nucleus of Patagonian Limit of Life (LiLi), Valdivia, Chile
| | - Tomás Altamirano
- ECOS (Ecology-Complexity-Society) Laboratory, Center for Local Development (CEDEL), Pontificia Universidad Católica de Chile, Villarrica Campus, La Araucanía Region, Chile,National Audubon Society and Cape Horn International Center for Global Change Studies and Biocultural Conservation, Universidad de Magallanes, Punta Arenas, Chile,Millennium Nucleus Center for the Socioeconomic Impact of Environmental Policies (CESIEP), Chile
| | - Francisco F. Bozinovic
- Center of Applied Ecology and Sustainability (CAPES), Pontificia Universidad Católica de Chile, Santiago, Chile,Departamento de Ecología Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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9
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Effects of paternal deprivation in social rodents. RUSSIAN JOURNAL OF THERIOLOGY 2022. [DOI: 10.15298/rusjtheriol.21.2.03] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Doty AC, Connior MB, Risch TS. Drivers of Southern Flying Squirrel (Glaucomys volans) Aggregation Size in South Carolina, U.S.A. AMERICAN MIDLAND NATURALIST 2022. [DOI: 10.1674/0003-0031-188.1.20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Anna C. Doty
- Department of Biology, California State University Bakersfield, 93311; Department of Biological Sciences, California State University Sacramento, Sacramento 95819
| | - Matthew B. Connior
- Department of Biological Sciences, Arkansas State University, State University 72467; Northwest Arkansas Community College, Bentonville 72712
| | - Thomas S. Risch
- Department of Biological Sciences, Arkansas State University, State University 72467; Arkansas Biosciences Institute, Arkansas State University, State University 72467
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11
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Wellens KR, Lee SM, Winans JC, Pusey AE, Murray CM. Female chimpanzee associations with male kin: trade-offs between inbreeding avoidance and infanticide protection. Anim Behav 2022. [DOI: 10.1016/j.anbehav.2022.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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12
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Toor I, Maynard R, Peng X, Beery AK, Holmes MM. Naked Mole-Rat Social Phenotypes Vary in Investigative and Aggressive Behavior in a Laboratory Partner Preference Paradigm. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.860885] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Here we employed the partner preference test (PPT) to examine how naked mole-rat non-breeding individuals of different behavioral phenotypes make social decisions. Naked mole-rats from six colonies were classified into three behavioral phenotypes (soldiers, dispersers, and workers) using a battery of behavioral tests. They then participated in a 3 h long PPT, where they could freely interact with a tethered familiar or tethered unfamiliar conspecific. By comparing the three behavioral phenotypes, we tested the hypothesis that the PPT can be used to interrogate social decision-making in this species, revealing individual differences in behavior that are consistent with discrete social phenotypes. We also tested whether a shorter, 10 min version of the paradigm is sufficient to capture group differences in behavior. Overall, soldiers had higher aggression scores toward unfamiliar conspecifics than both workers and dispersers at the 10 min and 3 h comparison times. At the 10 min comparison time, workers showed a stronger preference for the familiar animal’s chamber, as well as for investigating the familiar conspecific, compared to both dispersers and soldiers. At the 3 h time point, no phenotype differences were seen with chamber or investigation preference scores. Overall, all phenotypes spent more time in chambers with another animal vs. being alone. Use of the PPT in a comparative context has demonstrated that the test identifies species and group differences in affiliative and aggressive behavior toward familiar and unfamiliar animals, revealing individual differences in social decision-making and, importantly, capturing aspects of species-specific social organization seen in nature.
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Ebensperger LA, Quirici V, Bunster V, León C, Ramírez‐Estrada J, Hayes LD. Effects of Radio‐Collars are not Contingent on Socioecological Conditions in Degus. J Wildl Manage 2021. [DOI: 10.1002/jwmg.22098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Luis A. Ebensperger
- Departamento de Ecología, Facultad de Ciencias Biológicas Pontificia Universidad Católica de Chile Santiago Chile
| | - Verónica Quirici
- Centro de Investigación para la Sustentabilidad Facultad de Ciencias de la Vida, Universidad Andrés Bello, República 440 Santiago Chile
| | - Valentina Bunster
- Departamento de Ecología, Facultad de Ciencias Biológicas Pontificia Universidad Católica de Chile Santiago Chile
| | - Cecilia León
- Departamento de Ecología, Facultad de Ciencias Biológicas Pontificia Universidad Católica de Chile Santiago Chile
| | - Juan Ramírez‐Estrada
- 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 37403 TN USA
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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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15
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Ebensperger LA, Gómez C, Aspillaga-Cid A, León C, Ramírez-Estrada J, Correa LA, Vera DC, Abades S, Hayes LD. Socially unstable conditions experienced during development prime female Octodon degus to shape the phenotype of their own offspring. Horm Behav 2021; 134:105011. [PMID: 34130042 DOI: 10.1016/j.yhbeh.2021.105011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 05/29/2021] [Accepted: 05/31/2021] [Indexed: 11/15/2022]
Abstract
Because residents and immigrants from group living species may experience fitness costs associated with permanent changes in group membership, we examined the hypothesis that females experiencing socially unstable or socially stable conditions during development compensate these costs by shaping the phenotype of their own offspring differently. Groups of adult females experiencing either socially stable or unstable conditions in the early social environment were assigned to either socially stable or unstable conditions in the social environment as adults. We quantified affiliative and agonistic interactions among the females during pregnancy and lactation of the focal female, maternal and allomaternal care, hypothalamic-anterior pituitary-adrenal axis (HPA) acute stress response, and early offspring growth. Social instability during breeding enhanced agonistic interactions among adult females, and offspring that experienced socially unstable conditions exhibited enhanced offspring care, regardless of adult environments. Neither social behavior, offspring care, acute stress physiology, nor early growth was influenced by early or adult social stability conditions. These findings imply that socially unstable conditions prime developing females to shape the phenotype of their offspring to prevent negative effects of socially unstable environments.
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Affiliation(s)
- Luis A Ebensperger
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
| | - Celeste Gómez
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Antonia Aspillaga-Cid
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Cecilia León
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Juan Ramírez-Estrada
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Loreto A Correa
- Escuela de Medicina Veterinaria, Facultad de Ciencias, Universidad Mayor, Camino la Pirámide 5750, Huechuraba, Santiago, Chile
| | - Daniela C Vera
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Sebastian Abades
- GEMA Center for Genomics, Ecology & Environment, Facultad de Estudios Interdisciplinarios, Universidad Mayor, Camino La Pirámide 5750, Huechuraba, Santiago, Chile
| | - Loren D Hayes
- Department of Biology, Geology, and Environmental Sciences, University of Tennessee at Chattanooga, Chattanooga, TN 37403, USA
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16
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Cantano LMR, Luchesi LC, Takata JT, Monticelli PF. Behavioral repertoire of the Brazilian spiny-rats, Trinomys setosus and Clyomys laticeps: different levels of sociality. BRAZ J BIOL 2021; 83:e241164. [PMID: 34231655 DOI: 10.1590/1519-6984.241164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 03/02/2021] [Indexed: 11/22/2022] Open
Abstract
Behavior is a useful trait for comparative studies that provide the comprehension of phylogenetic relationships among species. Here, we present a description of two spiny-rats species' behavioral repertoire, Clyomys laticeps and Trinomys setosus (Rodentia: Echimyidae). The affiliative and agonistic behavioral patterns were sampled during a three-year study of captive populations of wild animals. Observational data were collected in two phases under different arrangements of individuals in groups. We also compare the behavioral traits of T. setosus and C. laticeps with the known behavioral patterns of Trinomys yonenagae. We add categories to the previous descriptions of T. setosus and a standard ethogram for C. laticeps. Trinomys setosus showed a visual and vocal display we called foot-trembling, which was not described in this form and function for other species studied until now. We discuss the differences in their sociality levels and similarities and differences among behavior patterns and repertoires.
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Affiliation(s)
- L M R Cantano
- Universidade de São Paulo - USP, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto - FFCLRP, Departamento de Psicologia, Laboratório de Etologia e Bioacústica - EBAC, Programa de Pós-Graduação em Psicobiologia em Psicobiologia, Ribeirão Preto, SP, Brasil
| | - L C Luchesi
- Universidade de São Paulo - USP, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto - FFCLRP, Departamento de Psicologia, Laboratório de Etologia e Bioacústica - EBAC, Programa de Pós-Graduação em Psicobiologia em Psicobiologia, Ribeirão Preto, SP, Brasil
| | - J T Takata
- Universidade de São Paulo - USP, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto - FFCLRP, Departamento de Psicologia, Laboratório de Etologia e Bioacústica - EBAC, Programa de Pós-Graduação em Psicobiologia em Psicobiologia, Ribeirão Preto, SP, Brasil
| | - P F Monticelli
- Universidade de São Paulo - USP, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto - FFCLRP, Departamento de Psicologia, Laboratório de Etologia e Bioacústica - EBAC, Programa de Pós-Graduação em Psicobiologia em Psicobiologia, Ribeirão Preto, SP, Brasil
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17
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Aspillaga-Cid A, Vera DC, Ebensperger LA, Correa LA. Parental care in male degus (Octodon degus) is flexible and contingent upon female care. Physiol Behav 2021; 238:113487. [PMID: 34087278 DOI: 10.1016/j.physbeh.2021.113487] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 05/26/2021] [Accepted: 05/27/2021] [Indexed: 11/30/2022]
Abstract
Parents in many animal species provide care to their offspring as a mechanism to enhance their own fitness. In mammals, this behavior is expressed mostly by the females, but also by males of some species. Proximally, rates of paternal offspring care have been linked to organizational and activational effects of testosterone. Specifically, intrauterine position of male fetuses is associated with differential exposure to testosterone, leading to development of males with different levels of masculinization (assessed through differences in the length of the anogenital distance (AGD). The relative roles played by organizational and activational effects of testosterone on male parental care remain unclear. In this study, we aimed to determine if male sex-biased uterine environment and testosterone levels across the breeding period explain variation in paternal care in the social rodent, Octodon degus. Neither quantity (time with the offspring) nor quality (frequency of grooming and retrieving) of paternal care was affected by male sex-biased uterine environment, nor did paternal care significantly differ across the different stages of male reproduction. In contrast, paternal care was associated with maternal care. Quantity of male care decreased with increasing quantity of maternal care, and quality of male care increased with increasing quality of maternal care. While serum testosterone did not differ between males with different sex-biased uterine environment, male testosterone tended to increase during mating and decrease when pregnant females or offspring were present.
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Affiliation(s)
- Antonia Aspillaga-Cid
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Daniela C Vera
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Luis A Ebensperger
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Loreto A Correa
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile; Escuela de Medicina Veterinaria, Facultad de Ciencias. Universidad Mayor, Camino la Pirámide 5750, Huechuraba, Santiago, Chile.
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18
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O’Brien SL, Tammone MN, Cuello PA, Lacey EA. Multi-year assessment of variability in spatial and social relationships in a subterranean rodent, the highland tuco-tuco (Ctenomys opimus). Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-03034-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Abstract
In some species, populations routinely contain a mixture of lone and group-living individuals. Such facultative sociality may reflect individual differences in behavior as well as adaptive responses to variation in local environmental conditions. To explore interactions between individual- and population-level variabilities in behavior in a species provisionally described as facultatively social, we examined spatial and social relationships within a population of highland tuco-tucos (Ctenomys opimus) at Laguna de los Pozuelos, Jujuy Province, Argentina. Using data collected over 5 consecutive years, we sought to (1) confirm the regular occurrence of both lone and group-living individuals and (2) characterize the temporal consistency of individual social relationships. Our analyses revealed that although the study population typically contained lone as well as group-living animals, individual spatial and social relationships varied markedly over time. Specifically, the extent to which individuals remained resident in the same location across years varied, as did the number of conspecifics with which an animal lived, with an overall tendency for individuals to live in larger groups over successive years. Collectively, these analyses indicate that population-level patterns of behavior in C. opimus are consistent with facultative sociality but that this variation does not arise due to persistent differences in individual behavior (i.e., living alone versus with conspecifics). Instead, based on changes in spatial and social relationships across years, we suggest that variation in the tendency to live in groups is shaped primarily by local ecological and demographic conditions.
Significance statement
Characterizing variation in conspecific relationships is critical to understanding the adaptive bases for social behavior. Using data collected over 5 successive years, we examined temporal variation in spatial and social relationships within a population of highland tuco-tucos (C. opimus) from northern Argentina. In addition to providing the first multi-year assessment of the behavior and demography of this species, our analyses generate important insights into relationships between individual behavior and population-level patterns of social organization. The behavioral variability evident in our study population suggests that C. opimus is an ideal system in which to explore the causes and consequences of individual differences in social behavior.
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19
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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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20
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Multiple dimensions of social motivation in adult female degus. PLoS One 2021; 16:e0250219. [PMID: 33882104 PMCID: PMC8059823 DOI: 10.1371/journal.pone.0250219] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 04/03/2021] [Indexed: 11/19/2022] Open
Abstract
Many animals become more motivated to interact after a period of isolation. This phenomenon may involve general drives, e.g. for social touch or companionship, as well as drives that are specific to particular peers, and which ultimately serve to reestablish relationships between the individuals. Female degus are known to be affiliative with multiple other individuals, including unrelated and unfamiliar conspecifics, offering an opportunity to study social motivation independent from exclusive pair-bonds or overt, same-sex competition. We attempted to disentangle factors driving peer interaction by examining reunion behavior across several social isolation and separation manipulations. High levels of interaction were observed between adult females who had been separated even without isolation, revealing a drive to re-establish relationships with specific peers. The content of separation-only reunions differed from isolation, with the latter involving more early-session interaction, higher levels of allogrooming before rear-sniffing, and a higher ratio of chitter vocalizations. To assess whether post-isolation behavior was related to stress, we examined reunions following a non-social (footshock) stressor. Like isolation, footshock increased early-session interactions, but did not increase allogrooming before rear-sniffing or chittering, as compared with controls. To test whether separation-only reunion behavior shared qualities with relationship formation, we also examined reunions of new (stranger) dyads. Strangers exhibited higher levels of interaction than cagemates, with particularly high levels of late-session rear-sniffing. Like separation-only reunions, strangers showed more non-chitter vocalizations and lower levels of allogrooming before rear-sniffing. Across experiments, an exploratory clustering method was used to identify vocalizations that differed between conditions. This yielded promising leads for future investigation, including a chaff-type syllable that may have been more common during relationship renewal. Overall, results are consistent with the hypothesis that female degu reunions are supported by both general and peer-stimulus specific drives, expressed through the structure of physical and vocal interactions over time.
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21
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Amaya JP, Cuello PA, Valentinuzzi VS, Lacey EA. Dynamic spatial overlap in a solitary subterranean rodent: the Anillaco tuco-tuco ( Ctenomys sp.). J Mammal 2021. [DOI: 10.1093/jmammal/gyab011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Abstract
Despite striking diversity in mammalian social behavior, studies of social organization have often dichotomized species by identifying them as either solitary or social (i.e., group living). This tendency has been particularly pronounced for subterranean rodents, the majority of which have long been assumed to be solitary. As a result, variation in social organization has likely been underestimated for these animals, particularly for species in which patterns of space use suggest limited or temporally dynamic opportunities for interactions among conspecifics. Here, we characterize patterns of space use in a population of tuco-tucos (Ctenomys sp.) from Anillaco, La Rioja Province, Argentina. Although these animals have been the subject of extensive research regarding circadian patterns of activity, spatial and social relationships among free-living individuals have not been documented. Analyses of radiotelemetry data from 17 individuals monitored during the breeding season (December 2015) revealed that partial overlap of individual home ranges was common, occurring between male–female as well as female–female pairs of animals. Spatial relationships, however, were dynamic, with both home range sizes and overlap changing on a daily basis. Although members of the study population did not meet the criteria typically used to identify group living in subterranean species, they were not completely solitary. Instead, the animals displayed an intermediate form of social organization characterized by persistent partial overlap of the areas occupied by different adults. These data add to the growing comparative picture of social variation in Ctenomys and suggest that further studies of these animals should contribute to improved understanding of the factors underlying differences in mammalian social systems.
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Affiliation(s)
- Juan P Amaya
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET), CP 5301 Anillaco, La Rioja, Argentina
- IBICOPA (Instituto de Biología de la Conservación y Paleobiología), DACEFYN-CENIIT-UNLaR, CP 5300 Ciudad de La Rioja, Argentina
| | - Pablo A Cuello
- Grupo de Investigaciones de la Biodiversidad (GiB), Instituto Argentino de Investigaciones de las Zonas Áridas (IADIZA), CONICET CCT-Mendoza, CC 507, CP 5500 Mendoza, Argentina
| | - Veronica S Valentinuzzi
- Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja (CRILAR-CONICET), CP 5301 Anillaco, La Rioja, Argentina
| | - Eileen A Lacey
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
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22
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van der Marel A, Waterman JM, López-Darias M. Social organization in a North African ground squirrel. J Mammal 2020. [DOI: 10.1093/jmammal/gyaa031] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Abstract
Research on sociality in temperate ground-dwelling squirrels has focused on female philopatry and other life history trade-offs, which are influenced by constraints in the duration of the active growing season. Temperate ground-dwelling squirrels that experience high predation pressure, are large in body size, and have a short active season, show a more complex social organization. In contrast, African ground squirrels are active year-round, suggesting that instead of a short active season, distinct selective pressures influence their social organization. We examined the social organization of Barbary ground squirrels, Atlantoxerus getulus, and compared the social organization of temperate and African ground-dwelling sciurids. Anecdotal accounts on Barbary ground squirrels’ social organization suggested that they were either solitary or gregarious, or live in small family groups. We recorded the group size, composition, cohesion, and genetic relatedness, of the population on the arid island of Fuerteventura, Spain. Our data indicate that females live in small (1–8) all-female kin groups separate from adult males, and that unrelated adult males share sleeping burrows with immature individuals of either sex. We observed sex-biased dispersal with males primarily the dispersing sex and females primarily philopatric. Females sleep solitarily during gestation and lactation and nest either communally or singly after juvenile emergence. During the day, males and females can be active in the same area. Barbary ground squirrels are social because the squirrels share sleeping burrows and show spatiotemporal overlap. Barbary ground squirrels’ social organization resembles that of the closely related Cape ground squirrel rather than that of the temperate ground-dwelling sciurids, although the former are more temperate, seasonal breeders. In addition to describing the social organization of a previously unstudied species, this paper sheds light on the ecological drivers of sociality, and the evolution of distinct social organizations in ground-dwelling sciurids.
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Affiliation(s)
| | - Jane M Waterman
- Department of Biological Sciences, University of Manitoba, 50 Sifton Road, Winnipeg, MB, Canada
| | - Marta López-Darias
- Island Ecology and Evolution Research Group, Instituto de Productos Naturales y Agrobiología (IPNA-CSIC), Av. Astrofisico Francisco Sánchez, 3, 38206 San Cristóbal de La Laguna, Santa Cruz de Tenerife, Canary Islands, Spain
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23
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Insel N, Shambaugh KL, Beery AK. Female degus show high sociality but no preference for familiar peers. Behav Processes 2020; 174:104102. [PMID: 32145271 DOI: 10.1016/j.beproc.2020.104102] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 03/03/2020] [Accepted: 03/03/2020] [Indexed: 11/17/2022]
Abstract
Group-living animals vary in social behavior across multiple dimensions, including in the selectivity of social interactions with familiar versus unfamiliar peers. Standardized behavioral tests can be used to tease apart different dimensions of behavior. These serve a dual function-on one hand, helping to isolate behavioral factors that may support collective behavior in natural habitats, and, on another, providing a basis for comparative approaches to understanding physiological mechanisms of behavior. Degus (Octodon degus) are South American caviomorph rodents that nest and forage in groups with relatively low genetic relatedness. Flexibility in group membership is likely supported by gregariousness toward strangers, but the relative preference for strangers compared with familiar individuals has not been systematically tested. We assessed the specificity of social preferences in female degus using a same-sex partner preference test. Degus huddled extensively with both familiar and unfamiliar peers, with no average preference for one over the other. Detailed analysis of social interactions demonstrated an effect of familiarity on social investigation and aggressive behaviors, indicating that degus distinguished between familiar and unfamiliar conspecifics, even though it did not impact huddling. This behavioral profile is thus far unique to degus; in similar tests, meadow and prairie voles exhibit strong partner preferences for known peers, while mice exhibit low social huddling and spend relatively less time in social chambers. Understanding how group-living species differ in specific aspects of social behavior such as familiarity/novelty preference and propensity for social contact will offer a foundation to interpret differences in neural systems supporting sociality.
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Affiliation(s)
- Nathan Insel
- Department of Psychology & Center for Structural and Functional Neuroscience, University of Montana, Missoula, MT, 59812, USA
| | - Katharine L Shambaugh
- Department of Psychology, Department of Biology, Program in Neuroscience. Smith College, Northampton, MA, 01063, USA
| | - Annaliese K Beery
- Department of Psychology, Department of Biology, Program in Neuroscience. Smith College, Northampton, MA, 01063, USA.
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24
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O’Brien SL, Tammone MN, Cuello PA, Lacey EA. Facultative sociality in a subterranean rodent, the highland tuco-tuco (Ctenomys opimus). Biol J Linn Soc Lond 2020. [DOI: 10.1093/biolinnean/blaa011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
Understanding why social relationships vary among conspecifics is central to studies of animal behaviour. For many species, patterns of space use provide important insights into social behaviour. To characterize the social organization of the highland tuco-tuco (Ctenomys opimus), we used visual observations and radiotelemetry to quantify spatial relationships among adults in a population at Laguna de los Pozuelos, Jujuy Province, Argentina. Specifically, we sought to confirm anecdotal reports that these subterranean rodents are social, meaning that adults share burrow systems and nest sites. Our data indicate that the animals live in spatially distinct groups, although the number of individuals per group varies markedly. Although these relationships were robust with regard to location (above vs. below ground) and type of data (visual vs. telemetry), some groups identified during the daytime fissioned during the night. We suggest that the population of C. opimus at Pozuelos is facultatively social, meaning that individuals display predictable, adaptive differences in social relationships with conspecifics. More generally, our findings add to the growing number of subterranean species of rodents recognized as social, thereby generating new opportunities for comparative studies of these animals aimed at assessing the causes and consequences of variation in social organization.
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Affiliation(s)
- Shannon L O’Brien
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Mauro N Tammone
- INIBIOMA-CONICET and Programa de Estudios Aplicados a la Conservación del Parque Nacional Nanhuel Huapi (CENAC-PHHN, CONICET), Rio Negro, Argentina
| | - Pablo A Cuello
- Instituto Argentino de Investigaciones de Zonas Aridas (IADIZA-CCT CONICET), Mendoza, Argentina
| | - Eileen A Lacey
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA, USA
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Fernández-Aburto P, Delgado SE, Sobrero R, Mpodozis J. Can social behaviour drive accessory olfactory bulb asymmetries? Sister species of caviomorph rodents as a case in point. J Anat 2019; 236:612-621. [PMID: 31797375 DOI: 10.1111/joa.13126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 10/13/2019] [Accepted: 11/04/2019] [Indexed: 12/21/2022] Open
Abstract
In mammals, the accessory olfactory or vomeronasal system exhibits a wide variety of anatomical arrangements. In caviomorph rodents, the accessory olfactory bulb (AOB) exhibits a dichotomic conformation, in which two subdomains, the anterior (aAOB) and the posterior (pAOB), can be readily distinguished. Interestingly, different species of this group exhibit bias of different sign between the AOB subdomains (aAOB larger than pAOB or vice versa). Such species-specific biases have been related with contrasting differences in the habitat of the different species (e.g. arid vs. humid environments). Aiming to deepen these observations, we performed a morphometric comparison of the AOB subdomains between two sister species of octodontid rodents, Octodon lunatus and Octodon degus. These species are interesting for comparative purposes, as they inhabit similar landscapes but exhibit contrasting social habits. Previous reports have shown that O. degus, a highly social species, exhibits a greatly asymmetric AOB, in which the aAOB has twice the size of the pAOB and features more and larger glomeruli in its glomerular layer (GL). We found that the same as in O. degus, the far less social O. lunatus also exhibits a bias, albeit less pronounced, to a larger aAOB. In both species, this bias was also evident for the mitral/tufted cells number. But unlike in O. degus, in O. lunatus this bias was not present at the GL. In comparison with O. degus, in O. lunatus the aAOB GL was significantly reduced in volume, while the pAOB GL displayed a similar volume. We conclude that these sister species exhibit a very sharp difference in the anatomical conformation of the AOB, namely, the relative size of the GL of the aAOB subdomain, which is larger in O. degus than in O. lunatus. We discuss these results in the context of the differences in the lifestyle of these species, highlighting the differences in social behaviour as a possible factor driving to distinct AOB morphometries.
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Affiliation(s)
- Pedro Fernández-Aburto
- Departamento de Biología, Laboratorio de Neurobiología y Biología del Conocer, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Scarlett E Delgado
- Departamento de Biología, Laboratorio de Neurobiología y Biología del Conocer, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
| | - Raúl Sobrero
- Laboratorio de Ecología de Enfermedades, Instituto de Ciencias Veterinarias del Litoral (ICiVet-Litoral), Universidad Nacional del Litoral (UNL), Esperanza, Santa Fe, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Esperanza, Santa Fe, Argentina
| | - Jorge Mpodozis
- Departamento de Biología, Laboratorio de Neurobiología y Biología del Conocer, Facultad de Ciencias, Universidad de Chile, Santiago, Chile
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Lacey EA, O’Brien SL, Sobrero R, Ebensperger LA. Spatial relationships among free-living cururos (Spalacopus cyanus) demonstrate burrow sharing and communal nesting. J Mammal 2019. [DOI: 10.1093/jmammal/gyz117] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Abstract
Spatial relationships among conspecifics can provide insights into numerous aspects of social behavior. Spatial data may be particularly important for characterizing the behavior of difficult-to-study species such as subterranean rodents, direct observations of which are challenging. To characterize the social organization of the cururo (Spalacopus cyanus), a subterranean species in the rodent family Octodontidae, we used radiotelemetry to quantify spatial relationships within populations of this species located in Parque Nacional Bosque Fray Jorge and Santuario de la Naturaleza Yerba Loca, Chile. Specifically, we sought to determine if adults in this diurnal species share burrows and subterranean nests, the two criteria typically used to identify subterranean rodents as social. Analyses of radio fixes collected during February–March 2003 revealed that cururos at both Fray Jorge and Yerba Loca shared nighttime nest sites; cluster analyses of these data identified multiple spatially distinct subsets of adults in each population. Overlap of minimum convex polygons constructed from radio fixes collected during daylight hours suggested burrow sharing by animals in both populations. Cluster analyses of overlap values revealed the same spatially distinct groups of individuals identified from analyses of nest sharing; in addition, these analyses revealed one cluster of animals in each population that was not evident from analyses of nighttime data. Collectively, these results confirm that cururos are social, with adults in both study populations sharing burrow systems and communal nests. Our findings add to the growing understanding of social organization in octodontid rodents and reveal a new system for comparative studies of the ecology and evolution of behavioral variation in burrow-dwelling mammals.
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Affiliation(s)
- Eileen A Lacey
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Shannon L O’Brien
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA, USA
| | - Raúl Sobrero
- Laboratorio de Ecología de Enfermedades, Instituto de Ciencias Veterinarias del Litoral (ICiVet-Litoral), Universidad Nacional del Litoral (UNL)/Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Esperanza, Santa Fe, Argentina
| | - Luis A Ebensperger
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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27
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Ebensperger LA, Correa LA, Ly Prieto Á, Pérez de Arce F, Abades S, Hayes LD. Multiple mating is linked to social setting and benefits the males in a communally rearing mammal. Behav Ecol 2019. [DOI: 10.1093/beheco/arz003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Individuals in social species may mate with multiple opposite-sex individuals, including members of the same or different social groups. This variation may be linked to genetic benefits, where multiple mating decreases risk of inbreeding. Multiple mating may also be constrained by the sociospatial setting through its effect on availability of mates. Because multiple mating with individuals from same or different groups may determine sex-specific fitness effects, we also examined how multiple mating modulates social benefits of females and males. We used 7 years of data on demography, social organization, and genetics of a natural population of the group-living and colonial rodent, Octodon degus, to determine how kin and sex composition within social groups, and spatial relations between these groups (i.e., colonial habits) influence multiple mating and its fitness consequences. Males (81.3%) and females (64.9%) produced offspring with multiple opposite-sex individuals within groups and with individuals of neighboring groups. Thus, polygynandry was the dominant mating system in the degu population examined. Multiple mating in degus was high when compared with estimates reported in other social mammals. Variation in female and male multiple mating was better explained by social setting through its effect on availability of potential mates rather than by benefits derived from decreasing risk of inbreeding. Finally, our study revealed how multiple mating enhances male, but not female reproductive success.
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Affiliation(s)
- Luis A Ebensperger
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Av. Libertador Bernardo O’Higgins, CP, Chile
| | - Loreto A Correa
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Av. Libertador Bernardo O’Higgins, CP, Chile
- Escuela de Medicina Veterinaria, Facultad de Ciencias, Universidad Mayor, Camino La Pirámide, Huechuraba, Santiago, Chile
| | - Álvaro Ly Prieto
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Av. Libertador Bernardo O’Higgins, CP, Chile
| | - Felipe Pérez de Arce
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Av. Libertador Bernardo O’Higgins, CP, Chile
| | - Sebastian Abades
- GEMA Center for Genomics, Ecology and Environment, Facultad de Ciencias, Universidad Mayor, Camino La Pirámide, Huechuraba, Santiago, Chile
| | - Loren D Hayes
- Department of Biological and Environmental Sciences, University of Tennessee at Chattanooga, Chattanooga, TN, USA
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Ferrando CPR, Lamberto JM, Leiner NO. Space use patterns of the burrowing echimyid rodent, Clyomys laticeps. Ethology 2019. [DOI: 10.1111/eth.12836] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Claire Pauline Röpke Ferrando
- Programa de Pós-Graduação em Ecologia e Conservação de Recursos Naturais; Universidade Federal de Uberlândia; Uberlândia MG Brazil
- Laboratório de Ecologia de Mamíferos, Instituto de Biologia; Universidade Federal de Uberlândia; Uberlândia MG Brazil
| | - Jenifer Martins Lamberto
- Programa de Pós-Graduação em Ecologia e Conservação de Recursos Naturais; Universidade Federal de Uberlândia; Uberlândia MG Brazil
- Laboratório de Ecologia de Mamíferos, Instituto de Biologia; Universidade Federal de Uberlândia; Uberlândia MG Brazil
| | - Natália Oliveira Leiner
- Laboratório de Ecologia de Mamíferos, Instituto de Biologia; Universidade Federal de Uberlândia; Uberlândia MG Brazil
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29
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Lee NS, Beery AK. Neural Circuits Underlying Rodent Sociality: A Comparative Approach. Curr Top Behav Neurosci 2019; 43:211-238. [PMID: 30710222 DOI: 10.1007/7854_2018_77] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
All mammals begin life in social groups, but for some species, social relationships persist and develop throughout the course of an individual's life. Research in multiple rodent species provides evidence of relatively conserved circuitry underlying social behaviors and processes such as social recognition and memory, social reward, and social approach/avoidance. Species exhibiting different complex social behaviors and social systems (such as social monogamy or familiarity preferences) can be characterized in part by when and how they display specific social behaviors. Prairie and meadow voles are closely related species that exhibit similarly selective peer preferences but different mating systems, aiding direct comparison of the mechanisms underlying affiliative behavior. This chapter draws on research in voles as well as other rodents to explore the mechanisms involved in individual social behavior processes, as well as specific complex social patterns. Contrasts between vole species exemplify how the laboratory study of diverse species improves our understanding of the mechanisms underlying social behavior. We identify several additional rodent species whose interesting social structures and available ecological and behavioral field data make them good candidates for study. New techniques and integration across laboratory and field settings will provide exciting opportunities for future mechanistic work in non-model species.
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Affiliation(s)
- Nicole S Lee
- Neuroscience and Behavior Program, University of Massachusetts, Amherst, MA, USA.
| | - Annaliese K Beery
- Neuroscience and Behavior Program, University of Massachusetts, Amherst, MA, USA. .,Department of Psychology, Smith College, Northampton, MA, USA. .,Neuroscience Program, Smith College, Northampton, MA, USA.
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30
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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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31
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Ebensperger LA, Aracena S, Avendaño N, Toro A, León C, Ramírez-Estrada J, Abades S. Social instability decreases alloparental care and quality of weaned offspring in a communally rearing rodent. Anim Behav 2017. [DOI: 10.1016/j.anbehav.2017.09.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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32
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Riede SJ, van der Vinne V, Hut RA. The flexible clock: predictive and reactive homeostasis, energy balance and the circadian regulation of sleep–wake timing. J Exp Biol 2017; 220:738-749. [DOI: 10.1242/jeb.130757] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
ABSTRACT
The Darwinian fitness of mammals living in a rhythmic environment depends on endogenous daily (circadian) rhythms in behavior and physiology. Here, we discuss the mechanisms underlying the circadian regulation of physiology and behavior in mammals. We also review recent efforts to understand circadian flexibility, such as how the phase of activity and rest is altered depending on the encountered environment. We explain why shifting activity to the day is an adaptive strategy to cope with energetic challenges and show how this can reduce thermoregulatory costs. A framework is provided to make predictions about the optimal timing of activity and rest of non-model species for a wide range of habitats. This Review illustrates how the timing of daily rhythms is reciprocally linked to energy homeostasis, and it highlights the importance of this link in understanding daily rhythms in physiology and behavior.
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Affiliation(s)
- Sjaak J. Riede
- Groningen Institute for Evolutionary Life Sciences, Chronobiology Unit, University of Groningen, Groningen 9747AG, The Netherlands
| | - Vincent van der Vinne
- Groningen Institute for Evolutionary Life Sciences, Chronobiology Unit, University of Groningen, Groningen 9747AG, The Netherlands
| | - Roelof A. Hut
- Groningen Institute for Evolutionary Life Sciences, Chronobiology Unit, University of Groningen, Groningen 9747AG, The Netherlands
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33
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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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34
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Correa LA, León C, Ramírez-Estrada J, Soto-Gamboa M, Sepúlveda RD, Ebensperger LA. Masculinized females produce heavier offspring in a group living rodent. J Anim Ecol 2016; 85:1552-1562. [DOI: 10.1111/1365-2656.12588] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 08/10/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Loreto A. Correa
- Departamento de Ecología; Facultad de Ciencias Biológicas; Pontificia Universidad Católica de Chile; Santiago Chile
| | - Cecilia León
- Departamento de Ecología; Facultad de Ciencias Biológicas; Pontificia Universidad Católica de Chile; Santiago Chile
| | - Juan Ramírez-Estrada
- Departamento de Ecología; Facultad de Ciencias Biológicas; Pontificia Universidad Católica de Chile; Santiago Chile
| | - Mauricio Soto-Gamboa
- Facultad de Ciencias; Instituto de Ciencias Ambientales y Evolutivas; Universidad Austral de Chile; Casilla 567 Valdivia Chile
| | - Roger D. Sepúlveda
- Facultad de Ciencias; Instituto de Ciencias Ambientales y Evolutivas; Universidad Austral de Chile; Casilla 567 Valdivia Chile
| | - Luis A. Ebensperger
- Departamento de Ecología; Facultad de Ciencias Biológicas; Pontificia Universidad Católica de Chile; Santiago Chile
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35
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Ebensperger LA, Correa LA, León C, Ramírez‐Estrada J, Abades S, Villegas Á, Hayes LD. The modulating role of group stability on fitness effects of group size is different in females and males of a communally rearing rodent. J Anim Ecol 2016; 85:1502-1515. [DOI: 10.1111/1365-2656.12566] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 06/13/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Luis A. Ebensperger
- Departamento de Ecología Facultad de Ciencias Biológicas Pontificia Universidad Católica de Chile Santiago Chile
| | - Loreto A. Correa
- Departamento de Ecología Facultad de Ciencias Biológicas Pontificia Universidad Católica de Chile Santiago Chile
| | - Cecilia León
- Departamento de Ecología Facultad de Ciencias Biológicas Pontificia Universidad Católica de Chile Santiago Chile
| | - Juan Ramírez‐Estrada
- Departamento de Ecología Facultad de Ciencias Biológicas Pontificia Universidad Católica de Chile Santiago Chile
| | - Sebastian Abades
- Departamento de Ecología Facultad de Ciencias Biológicas Pontificia Universidad Católica de Chile Santiago Chile
- Instituto de Ecología y Biodiversidad (IEB) Las Palmeras 3425 Santiago Chile
| | - Álvaro Villegas
- 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
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36
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Sobrero R, Fernández-Aburto P, Ly-Prieto Á, Delgado SE, Mpodozis J, Ebensperger LA. Effects of Habitat and Social Complexity on Brain Size, Brain Asymmetry and Dentate Gyrus Morphology in Two Octodontid Rodents. BRAIN, BEHAVIOR AND EVOLUTION 2016; 87:51-64. [DOI: 10.1159/000444741] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 02/17/2016] [Indexed: 11/19/2022]
Abstract
Navigational and social challenges due to habitat conditions and sociality are known to influence dentate gyrus (DG) morphology, yet the relative importance of these factors remains unclear. Thus, we studied three natural populations of O. lunatus (Los Molles) and Octodon degus (El Salitre and Rinconada), two caviomorph species that differ in the extent of sociality and with contrasting vegetation cover of habitat used. The brains and DG of male and female breeding degus with simultaneous information on their physical and social environments were examined. The extent of sociality was quantified from total group size and range area overlap. O. degus at El Salitre was more social than at Rinconada and than O. lunatus from Los Molles. The use of transects to quantify cover of vegetation (and other physical objects in the habitat) and measures of the spatial behavior of animals indicated animal navigation based on unique cues or global landmarks is more cognitively challenging to O. lunatus. During lactation, female O. lunatus had larger brains than males. Relative DG volume was similar across sexes and populations. The right hemisphere of male and female O. lunatus had more cells than the left hemisphere, with DG directional asymmetry not found in O. degus. Degu population differences in brain size and DG cell number seemed more responsive to differences in habitat than to differences in sociality. Yet, large-sized O. degus (but not O. lunatus) that ranged over larger areas and were members of larger social groups had more DG cells per hemisphere. Thus, within-population variation in DG cell number by hemisphere was consistent with a joint influence of habitat and sociality in O. degus at El Salitre.
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Ebensperger LA, Pérez de Arce F, Abades S, Hayes LD. Limited and fitness-neutral effects of resource heterogeneity on sociality in a communally rearing rodent. J Mammal 2016; 97:1125-1135. [PMID: 30302032 DOI: 10.1093/jmammal/gyw056] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Contrasting scenarios have been proposed to explain how resource heterogeneity influences group living or sociality. First, sociality may result from individuals in larger groups attaining net fitness benefits by monopolizing access to resources ("resource-defense" hypothesis). Second, sociality may be the fitness-neutral outcome of multiple individuals using a territory with sufficient resources to sustain a group of conspecifics ("resource-dispersion" hypothesis). While previous studies have tended to support the resource-dispersion hypothesis, these analyses have typically examined only 1 or a few predictions, making it difficult to distinguish between the 2 alternatives. We conducted a 4-year field study of Octodon degus to quantify the effects of spatial heterogeneity in food and refuge distributions on group size and 2 components of reproductive success (per capita number of offspring, offspring survival) in this plural breeding and communal rearing rodent. We found only a small effect of heterogeneity of food resources on group size; the effect food resource distribution on group territory size varied across years. Group size did not vary with spatial variation in group territory size and quality. Importantly, there was no covariation between group size and quality of an individual's territory (i.e., a measure of individual access to resources), or between this measure of territory quality and reproductive success, implying no resource-based benefits to social degus. Overall, our results were more consistent with fitness-neutral relationships among spatial heterogeneity of resources, sociality, and territory size. The resource-dispersion hypothesis, however, did not provide a complete explanation for degu socioecology. Se han propuesto distintas hipótesis para explicar cómo la heterogeneidad de los recursos afecta la vida en grupos, o sociabilidad. Esta puede surgir en situaciones donde individuos en grupos grandes se benefician al monopolizar el acceso a recursos (hipótesis de defensa de recursos). Por otra parte, la vida en grupos también puede ser el resultado neutro (en términos de adecuación) de individuos que comparten un territorio con recursos suficientes (hipótesis de dispersión de recursos). Aunque algunos estudios previos han validado la hipótesis de dispersión de recursos, estos solo han evaluado un número limitado de las predicciones de esta hipótesis, lo que ha dificultado distinguir entre esta y otras hipótesis alternativas. Durante un estudio de 4 años cuantificamos los efectos de la heterogeneidad espacial de alimento y distribución de refugios sobre el tamaño de grupo y dos componentes del éxito reproductivo (número per cápita de crías, supervivencia de las crías) en Octodon degus. Se registraron efectos relativamente pequeños de la heterogeneidad espacial del alimento sobre el tamaño de grupo, y variables entre años sobre el tamaño del territorio de cada grupo. El tamaño de grupo no fue afectado por la variación espacial en el tamaño y calidad del territorio de los grupos. No se registró co-variación entre el tamaño de los grupos y la calidad del territorio de cada individuo (una medida individual del acceso a recursos), o entre la calidad del territorio individual y el éxito reproductivo, lo que sugiere ausencia de beneficios derivados del uso social de recursos en degus. En general, los resultados fueron más consistentes con un escenario de efectos neutros de la heterogeneidad espacial de recursos sobre la sociabilidad. Sin embargo, la hipótesis de dispersión de recursos no explicó el conjunto de efectos (o su ausencia) asociados a la socioecología del degu.
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Affiliation(s)
- Luis A Ebensperger
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O'Higgins 340, Santiago CP 8831150, Chile (LAE, FPA, SA).,Department of Biology, Geology, and Environmental Sciences, University of Tennessee at Chattanooga, 215 Holt Hall, Department 2653, 615 McCallie Avenue, Chattanooga, TN 37403, USA (LDH).,Instituto de Ecología y Biodiversidad (IEB), Las Palmeras 3425, Ñuñoa, Santiago, Chile (SA)
| | - Felipe Pérez de Arce
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O'Higgins 340, Santiago CP 8831150, Chile (LAE, FPA, SA).,Department of Biology, Geology, and Environmental Sciences, University of Tennessee at Chattanooga, 215 Holt Hall, Department 2653, 615 McCallie Avenue, Chattanooga, TN 37403, USA (LDH).,Instituto de Ecología y Biodiversidad (IEB), Las Palmeras 3425, Ñuñoa, Santiago, Chile (SA)
| | - Sebastian Abades
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O'Higgins 340, Santiago CP 8831150, Chile (LAE, FPA, SA).,Department of Biology, Geology, and Environmental Sciences, University of Tennessee at Chattanooga, 215 Holt Hall, Department 2653, 615 McCallie Avenue, Chattanooga, TN 37403, USA (LDH).,Instituto de Ecología y Biodiversidad (IEB), Las Palmeras 3425, Ñuñoa, Santiago, Chile (SA)
| | - Loren D Hayes
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O'Higgins 340, Santiago CP 8831150, Chile (LAE, FPA, SA).,Department of Biology, Geology, and Environmental Sciences, University of Tennessee at Chattanooga, 215 Holt Hall, Department 2653, 615 McCallie Avenue, Chattanooga, TN 37403, USA (LDH).,Instituto de Ecología y Biodiversidad (IEB), Las Palmeras 3425, Ñuñoa, Santiago, Chile (SA)
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Davis GT, Vásquez RA, Poulin E, Oda E, Bazán-León EA, Ebensperger LA, Hayes LD. Octodon degus
kin and social structure. J Mammal 2015. [DOI: 10.1093/jmammal/gyv182] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
A growing body of evidence showing that individuals of some social species live in non-kin groups suggests kin selection is not required in all species for sociality to evolve. Here, we investigate 2 populations of Octodon degus , a widespread South American rodent that has been shown to form kin and non-kin groups. We quantified genetic relatedness among individuals in 23 social groups across 2 populations as well as social network parameters (association, strength, and clustering coefficient) in order to determine if these aspects of sociality were driven by kinship. Additionally, we analyzed social network parameters relative to ecological conditions at burrow systems used by groups, to determine if ecological characteristics within each population could explain variation in sociality. We found that genetic relatedness among individuals within social groups was not significantly higher than genetic relatedness among randomly selected individuals in both populations, suggesting that non-kin structure of groups is common in degus. In both populations, we found significant relationships between the habitat characteristics of burrow systems and the social network characteristics of individuals inhabiting those burrow systems. Our results suggest that degu sociality is non-kin based and that degu social networks are influenced by local conditions.
Es creciente la evidencia que apoya la ocurrencia de especies sociales donde los individuos no están emparentados genéticamente, lo que sugiere que la selección de parentesco no es indispensable para la evolución de la sociabilidad. En este estudio se examinaron dos poblaciones de Octodon degus , un roedor sudamericano donde los grupos sociales pueden o no incluir individuos cercanamente emparentados. Se cuantificó el parentesco genético entre individuos en 23 grupos sociales y en redes sociales de dos poblaciones para determinar si estos aspectos de la sociabilidad dependen del grado de parentesco. Además, se examinaron asociaciones entre los parámetros cuantificados de las redes sociales (asociación, fuerza, coeficiente de anidamiento) y las condiciones ecológicas a nivel de los sistemas de madriguera usados por cada grupo. El grado de parentesco genético dentro de los grupos no fue distinto del grado de parentesco entre individuos de la población tomados al azar, lo que apoya que una estructura de grupos no emparentada es la regla en Octodon degus . En ambas poblaciones se registró una asociación entre características ecológicas de los sistemas de madriguera y atributos de las redes sociales de los individuos que usan estas estructuras. Nuestros resultados indican que la sociabilidad en Octodon degus no está basada en relaciones de parentesco y que las redes sociales de estos animales dependen de las condiciones ecológicas.
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Lapointe MA, Bauer CM, Ebensperger LA, Reed JM, Romero LM. Livetrapping is not biased by the endocrine stress response: a preliminary study in the degu (Octodon degus). J Mammal 2015. [DOI: 10.1093/jmammal/gyv081] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Self-organization in the dynamics of huddling behavior in Octodon degus in two contrasting seasons. Behav Ecol Sociobiol 2015. [DOI: 10.1007/s00265-015-1894-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Early olfactory environment influences social behaviour in adult Octodon degus. PLoS One 2015; 10:e0118018. [PMID: 25671542 PMCID: PMC4324768 DOI: 10.1371/journal.pone.0118018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 01/05/2015] [Indexed: 11/19/2022] Open
Abstract
We evaluated the extent to which manipulation of early olfactory environment can influence social behaviours in the South American Hystricognath rodent Octodon degus. The early olfactory environment of newborn degus was manipulated by scenting all litter members with eucalyptol during the first month of life. The social behaviour of sexually mature animals (5–7 months old) towards conspecifics was then assessed using a y-maze to compare the response of control (naïve) and treated animals to two different olfactory configurations (experiment 1): (i) a non-familiarized conspecific impregnated with eucalyptol (eucalyptol arm) presented against (ii) a non-familiarized unscented conspecific (control arm). In addition, in dyadic encounters, we assessed the behaviour of control and eucalyptol treated animals towards a non-familiarized conspecific scented with eucalyptol (experiment 2). We found that control subjects explored and spent significantly less time in the eucalyptol arm, indicating neophobic behaviours towards the artificially scented conspecific. Treated subjects explored and spent similar time in both arms of the maze, showing the same interest for both olfactory stimuli presented. During dyadic encounters in experiment 2, an interaction effect between early experience and sex was observed. Control males escaped and avoided their scented partner more frequently than eucalyptol treated male subjects and than females. Both groups did not differ in the exploration of their scented partners, suggesting that avoidance within agonistic context does not relate to neophobic behaviours. Our results suggest that the exposure to eucalyptol during early ontogeny decreases evasive behaviours within an agonistic context as a result of olfactory learning. Altogether, these results indicate that olfactory cues learned in early ontogeny can influence olfactory-guided behaviours in adult degus.
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Ebensperger LA, León C, Ramírez-Estrada J, Abades S, Hayes LD, Nova E, Salazar F, Bhattacharjee J, Becker MI. Immunocompetence of breeding females is sensitive to cortisol levels but not to communal rearing in the degu (Octodon degus). Physiol Behav 2014; 140:61-70. [PMID: 25497887 DOI: 10.1016/j.physbeh.2014.12.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 12/10/2014] [Accepted: 12/11/2014] [Indexed: 01/15/2023]
Abstract
One hypothesis largely examined in social insects is that cooperation in the context of breeding benefits individuals through decreasing the burden of immunocompetence and provide passive immunity through social contact. Similarly, communal rearing in social mammals may benefit adult female members of social groups by reducing the cost of immunocompetence, and through the transfer of immunological compounds during allonursing. Yet, these benefits may come at a cost to breeders in terms of a need to increase investment in individual immunocompetence. We examined how these potential immunocompetence costs and benefits relate to reproductive success and survival in a natural population of the communally rearing rodent, Octodon degus. We related immunocompetence (based on ratios of white blood cell counts, total and specific immunoglobulins of G isotype titers) and fecal glucocorticoid metabolite (FGC) levels of adults immunized with hemocyanin from the mollusk Concholepas concholepas to measures of sociality (group size) and communal rearing (number of breeding females). Offspring immunocompetence was quantified based on circulating levels of the same immune parameters. Neither female nor offspring immunocompetence was influenced by communal rearing or sociality. These findings did not support that communal rearing and sociality enhance the ability of females to respond to immunological challenges during lactation, or contribute to enhance offspring condition (based on immunocompetence) or early survival (i.e., to 3months of age). Instead, levels of humoral and cellular components of immunocompetence were associated with variation in glucorcorticoid levels of females. We hypothesize that this covariation is driven by physiological (life-history) adjustments needed to sustain breeding.
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Affiliation(s)
- Luis A Ebensperger
- 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
| | - Juan Ramírez-Estrada
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile
| | - Sebastian Abades
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile; Instituto de Ecología y Biodiversidad (IEB), Las Palmeras 3425, Ñuñoa, Santiago, Chile
| | - Loren D Hayes
- Department of Biological and Environmental Sciences, University of Tennessee at Chattanooga, Chattanooga, TN 37403, USA
| | - Esteban Nova
- Fundación Ciencia y Tecnología para el Desarrollo (FUCITED), Santiago, Chile
| | - Fabián Salazar
- Fundación Ciencia y Tecnología para el Desarrollo (FUCITED), Santiago, Chile
| | | | - María Inés Becker
- Fundación Ciencia y Tecnología para el Desarrollo (FUCITED), Santiago, Chile; Biosonda Corporation, Santiago, Chile
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Rivera DS, Abades S, Alfaro FD, Ebensperger LA. Sociality ofOctodontomys gliroidesand other octodontid rodents reflects the influence of phylogeny. J Mammal 2014. [DOI: 10.1644/14-mamm-a-057] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Fang X, Seim I, Huang Z, Gerashchenko MV, Xiong Z, Turanov AA, Zhu Y, Lobanov AV, Fan D, Yim SH, Yao X, Ma S, Yang L, Lee SG, Kim EB, Bronson RT, Šumbera R, Buffenstein R, Zhou X, Krogh A, Park TJ, Zhang G, Wang J, Gladyshev VN. Adaptations to a subterranean environment and longevity revealed by the analysis of mole rat genomes. Cell Rep 2014; 8:1354-64. [PMID: 25176646 PMCID: PMC4350764 DOI: 10.1016/j.celrep.2014.07.030] [Citation(s) in RCA: 136] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Revised: 05/11/2014] [Accepted: 07/17/2014] [Indexed: 02/06/2023] Open
Abstract
Subterranean mammals spend their lives in dark, unventilated environments that are rich in carbon dioxide and ammonia and low in oxygen. Many of these animals are also long-lived and exhibit reduced aging-associated diseases, such as neurodegenerative disorders and cancer. We sequenced the genome of the Damaraland mole rat (DMR, Fukomys damarensis) and improved the genome assembly of the naked mole rat (NMR, Heterocephalus glaber). Comparative genome analyses, along with the transcriptomes of related subterranean rodents, revealed candidate molecular adaptations for subterranean life and longevity, including a divergent insulin peptide, expression of oxygen-carrying globins in the brain, prevention of high CO2-induced pain perception, and enhanced ammonia detoxification. Juxtaposition of the genomes of DMR and other more conventional animals with the genome of NMR revealed several truly exceptional NMR features: unusual thermogenesis, an aberrant melatonin system, pain insensitivity, and unique processing of 28S rRNA. Together, these genomes and transcriptomes extend our understanding of subterranean adaptations, stress resistance, and longevity.
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Affiliation(s)
- Xiaodong Fang
- BGI-Shenzhen, Shenzhen 518083, China; Department of Biology, University of Copenhagen, Copenhagen, 2200 Copenhagen N, Denmark
| | - Inge Seim
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; Department of Bioinspired Science, Ewha Womans University, Seoul 120-750, South Korea
| | | | - Maxim V Gerashchenko
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | | | - Anton A Turanov
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | | | - Alexei V Lobanov
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | | | - Sun Hee Yim
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | | | - Siming Ma
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Lan Yang
- BGI-Shenzhen, Shenzhen 518083, China
| | - Sang-Goo Lee
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; Department of Bioinspired Science, Ewha Womans University, Seoul 120-750, South Korea
| | - Eun Bae Kim
- Department of Bioinspired Science, Ewha Womans University, Seoul 120-750, South Korea
| | - Roderick T Bronson
- Rodent Histopathology Laboratory, Harvard Medical School, Boston, MA 02115, USA
| | - Radim Šumbera
- University of South Bohemia, Faculty of Science, Ceske Budejovice 37005, Czech Republic
| | - Rochelle Buffenstein
- Department of Physiology and The Sam and Ann Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center, San Antonio, TX 78245, USA
| | - Xin Zhou
- BGI-Shenzhen, Shenzhen 518083, China
| | - Anders Krogh
- Department of Biology, University of Copenhagen, Copenhagen, 2200 Copenhagen N, Denmark
| | - Thomas J Park
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Guojie Zhang
- BGI-Shenzhen, Shenzhen 518083, China; Department of Biology, University of Copenhagen, Copenhagen, 2200 Copenhagen N, Denmark
| | - Jun Wang
- BGI-Shenzhen, Shenzhen 518083, China; Department of Biology, University of Copenhagen, Copenhagen, 2200 Copenhagen N, Denmark; King Abdulaziz University, Jeddah 21441, Saudi Arabia.
| | - Vadim N Gladyshev
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; Department of Bioinspired Science, Ewha Womans University, Seoul 120-750, South Korea.
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Ebensperger LA, Villegas Á, Abades S, Hayes LD. Mean ecological conditions modulate the effects of group living and communal rearing on offspring production and survival. Behav Ecol 2014. [DOI: 10.1093/beheco/aru061] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Echeverría AI, Becerra F, Vassallo AI. Postnatal ontogeny of limb proportions and functional indices in the subterranean rodentCtenomys talarum(Rodentia: Ctenomyidae). J Morphol 2014; 275:902-13. [DOI: 10.1002/jmor.20267] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 12/20/2013] [Accepted: 02/26/2014] [Indexed: 11/10/2022]
Affiliation(s)
- Alejandra Isabel Echeverría
- Grupo Morfología Funcional y Comportamiento; Instituto de Investigaciones Marinas y Costeras (IIMyC), Universidad Nacional de Mar del Plata (UNMdP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); 7600 Mar del Plata Buenos Aires Argentina
| | - Federico Becerra
- Grupo Morfología Funcional y Comportamiento; Instituto de Investigaciones Marinas y Costeras (IIMyC), Universidad Nacional de Mar del Plata (UNMdP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); 7600 Mar del Plata Buenos Aires Argentina
| | - Aldo Iván Vassallo
- Grupo Morfología Funcional y Comportamiento; Instituto de Investigaciones Marinas y Costeras (IIMyC), Universidad Nacional de Mar del Plata (UNMdP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); 7600 Mar del Plata Buenos Aires Argentina
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Sobrero R, Prieto ÁL, Ebensperger LA. Activity, overlap of range areas, and sharing of resting locations in the moon-toothed degu,Octodon lunatus. J Mammal 2014. [DOI: 10.1644/13-mamm-a-144.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Bauer CM, Hayes LD, Ebensperger LA, Romero LM. Seasonal variation in the degu (Octodon degus) endocrine stress response. Gen Comp Endocrinol 2014; 197:26-32. [PMID: 24321176 DOI: 10.1016/j.ygcen.2013.11.025] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 11/23/2013] [Accepted: 11/28/2013] [Indexed: 10/25/2022]
Abstract
Many wild animals show seasonal variation in circulating levels of stress hormones. Seasonal changes in the stress response may help animals better cope with the different challenges faced during each life history stage. We determined the seasonal stress profile of wild, free-living degus in Chile. Female degus were sampled during non-breeding (January), mating/early gestation (July), late gestation (August), and lactation (1st litter-September, 2nd litter-January). Male degus were sampled during the first three time-points. We measured baseline cortisol (CORT), stress-induced CORT, and negative feedback efficacy using a dexamethasone suppression test. While we found that neither males nor females showed seasonal variation in baseline CORT or negative feedback levels, we did find significant seasonal variation in stress-induced CORT levels of both sexes. Male stress-induced CORT was lowest during mating while female stress-induced CORT was highest during late gestation and lactation. Overall, females had higher stress-induced CORT compared to males. Our data suggest that stress-induced levels of CORT are highest during periods with increased chance of stressor exposure or times of positive energy balance. Consequently, CORT responses to stress appear to be regulated according to different life history needs.
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Affiliation(s)
| | - Loren D Hayes
- Department of Biological and Environmental Sciences, University of Tennessee at Chattanooga, TN, USA
| | - Luis A Ebensperger
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
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Becerra F, Echeverría AI, Casinos A, Vassallo AI. Another one bites the dust: Bite force and ecology in three caviomorph rodents (Rodentia, Hystricognathi). ACTA ACUST UNITED AC 2014; 321:220-32. [DOI: 10.1002/jez.1853] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 12/18/2013] [Accepted: 01/06/2014] [Indexed: 11/05/2022]
Affiliation(s)
- Federico Becerra
- Departamento de Biología-Instituto de Investigaciones Marinas y Costeras (IIMyC); Universidad Nacional de Mar del Plata (UNMdP)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Mar del Plata Buenos Aires Argentina
| | - Alejandra Isabel Echeverría
- Departamento de Biología-Instituto de Investigaciones Marinas y Costeras (IIMyC); Universidad Nacional de Mar del Plata (UNMdP)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Mar del Plata Buenos Aires Argentina
| | - Adrià Casinos
- Departament de Biologia Animal; Universitat de Barcelona (UB); Barcelona Spain
| | - Aldo Iván Vassallo
- Departamento de Biología-Instituto de Investigaciones Marinas y Costeras (IIMyC); Universidad Nacional de Mar del Plata (UNMdP)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Mar del Plata Buenos Aires Argentina
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Muralidhar P, de Sá FP, Haddad CFB, Zamudio KR. Kin-bias, breeding site selection and female fitness in a cannibalistic Neotropical frog. Mol Ecol 2013; 23:453-63. [DOI: 10.1111/mec.12592] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 10/31/2013] [Accepted: 11/07/2013] [Indexed: 11/28/2022]
Affiliation(s)
- P. Muralidhar
- Department of Ecology and Evolutionary Biology; Cornell University; Ithaca NY 14853 USA
| | - F. P. de Sá
- Departamento de Zoologia; Instituto de Biociências; Universidade Estadual Paulista - UNESP, Cx; Postal 199 13506-900 Rio Claro São Paulo Brazil
| | - C. F. B. Haddad
- Departamento de Zoologia; Instituto de Biociências; Universidade Estadual Paulista - UNESP, Cx; Postal 199 13506-900 Rio Claro São Paulo Brazil
| | - K. R. Zamudio
- Department of Ecology and Evolutionary Biology; Cornell University; Ithaca NY 14853 USA
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