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Lacey EA, O’Brien SL, Cuello PA, Tammone MN. Group living in highland tuco-tucos (Ctenomys opimus) persists despite a catastrophic decline in population density. PLoS One 2024; 19:e0304763. [PMID: 38848416 PMCID: PMC11161065 DOI: 10.1371/journal.pone.0304763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 05/19/2024] [Indexed: 06/09/2024] Open
Abstract
Identifying the factors that favor group living is central to studies of animal social behavior. One demographic parameter that is expected to substantially shape spatial and social relationships is population density. Specifically, high population densities may favor group living by constraining opportunities to live alone. In contrast, low densities may allow individuals to spread out within the habitat, leading to a reduction in the prevalence or size of social groups. Abrupt changes in density following natural catastrophic events provide important opportunities to evaluate the effects of population density on patterns of spatial and social organization. As part of long-term studies of the behavioral ecology of a population of highland tuco-tucos (Ctenomys opimus) at Monumento Natural Laguna de los Pozuelos, Jujuy Province, Argentina, we monitored the demographic and behavioral consequences of a flood that inundated our study site during December 2012. Unlike most species of Ctenomys studied to date, highland tuco-tucos are group living, meaning that multiple adults share burrow systems and nest sites. Despite a post-flood reduction in population density of ~75%, animals present on the study site during the 2013 breeding season continued to live in multi-adult social units (groups). No differences between pre- and post-flood home range sizes were detected and although between-unit spatial overlap was reduced in 2013, overlap within social units did not differ from that in pre-flood years. Animals assigned to the same social unit in 2013 had not lived together during 2012, indicating that post-flood groups were not simply the remnants of those present prior to the flood. Collectively, these findings indicate that group living in highland tuco-tucos is not driven by the density of conspecifics in the habitat. In addition to enhancing understanding of the adaptive bases for group living in Ctenomys, our analyses underscore the power of catastrophic events to generate insights into fundamental aspects of social behavior.
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Affiliation(s)
- Eileen A. Lacey
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California, United States of America
- Department of Integrative Biology, University of California, Berkeley, Berkeley, California, United States of America
| | - Shannon L. O’Brien
- Museum of Vertebrate Zoology, University of California, Berkeley, Berkeley, California, United States of America
- Department of Integrative Biology, University of California, Berkeley, Berkeley, California, United States of America
- Animal Welfare Science Program, Lincoln Park Zoo, Chicago, Illinois, United States of America
| | - Pablo A. Cuello
- Instituto Argentino de Investigaciones de Zonas Áridas, CONICET-Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Mauro N. Tammone
- Instituto de Investigaciones en Biodiversidad y Medioambiente (CONICET-UNComahue), Bariloche, Río Negro, Argentina
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2
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Motes-Rodrigo A, Albery GF, Negron-Del Valle J, Philips D, Platt M, Brent LJ, Testard C. A natural disaster exacerbates and redistributes disease risk across free-ranging macaques by altering social structure. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.07.17.549341. [PMID: 37503037 PMCID: PMC10370147 DOI: 10.1101/2023.07.17.549341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Climate change is intensifying extreme weather events, with severe implications for ecosystem dynamics. A key behavioural mechanism whereby animals may cope with such events is by increasing social cohesion to improve access to scarce resources like refuges, which in turn could exacerbate epidemic risk due to increased close contact. However, how and to what extent natural disasters affect disease risk via changes in sociality remains unexplored in animal populations. By modelling disease spread in free-living rhesus macaque groups (Macaca mulatta) before and after a hurricane, we demonstrate doubled pathogen transmission rates up to five years following the disaster, equivalent to an increase in pathogen infectivity from 10% to 20%. Moreover, the hurricane redistributed the risk of infection across the population, decreasing status-related differences found in pre-hurricane years. These findings demonstrate that natural disasters can exacerbate and homogenise epidemic risk in an animal population via changes in sociality. These observations provide unexpected further mechanisms by which extreme weather events can threaten wildlife health, population viability, and spillover to humans.
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3
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Vogt CC, Zipple MN, Sprockett DD, Miller CH, Hardy SX, Arthur MK, Greenstein AM, Colvin MS, Michel LM, Moeller AH, Sheehan MJ. Female behavior drives the formation of distinct social structures in C57BL/6J versus wild-derived outbred mice in field enclosures. BMC Biol 2024; 22:35. [PMID: 38355587 PMCID: PMC10865716 DOI: 10.1186/s12915-024-01809-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 01/02/2024] [Indexed: 02/16/2024] Open
Abstract
BACKGROUND Social behavior and social organization have major influences on individual health and fitness. Yet, biomedical research focuses on studying a few genotypes under impoverished social conditions. Understanding how lab conditions have modified social organizations of model organisms, such as lab mice, relative to natural populations is a missing link between socioecology and biomedical science. RESULTS Using a common garden design, we describe the formation of social structure in the well-studied laboratory mouse strain, C57BL/6J, in replicated mixed-sex populations over 10-day trials compared to control trials with wild-derived outbred house mice in outdoor field enclosures. We focus on three key features of mouse social systems: (i) territory establishment in males, (ii) female social relationships, and (iii) the social networks formed by the populations. Male territorial behaviors were similar but muted in C57 compared to wild-derived mice. Female C57 sharply differed from wild-derived females, showing little social bias toward cage mates and exploring substantially more of the enclosures compared to all other groups. Female behavior consistently generated denser social networks in C57 than in wild-derived mice. CONCLUSIONS C57 and wild-derived mice individually vary in their social and spatial behaviors which scale to shape overall social organization. The repeatable societies formed under field conditions highlights opportunities to experimentally study the interplay between society and individual biology using model organisms.
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Affiliation(s)
- Caleb C Vogt
- Laboratory for Animal Social Evolution and Recognition, Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, 14853, USA.
| | - Matthew N Zipple
- Laboratory for Animal Social Evolution and Recognition, Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, 14853, USA
| | - Daniel D Sprockett
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Caitlin H Miller
- Laboratory for Animal Social Evolution and Recognition, Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, 14853, USA
| | - Summer X Hardy
- Laboratory for Animal Social Evolution and Recognition, Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, 14853, USA
| | - Matthew K Arthur
- Laboratory for Animal Social Evolution and Recognition, Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, 14853, USA
| | - Adam M Greenstein
- Laboratory for Animal Social Evolution and Recognition, Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, 14853, USA
| | - Melanie S Colvin
- Laboratory for Animal Social Evolution and Recognition, Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, 14853, USA
| | - Lucie M Michel
- Laboratory for Animal Social Evolution and Recognition, Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, 14853, USA
| | - Andrew H Moeller
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14853, USA
| | - Michael J Sheehan
- Laboratory for Animal Social Evolution and Recognition, Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, 14853, USA.
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4
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Hoffmann LB, McVicar EA, Harris RV, Collar-Fernández C, Clark MB, Hannan AJ, Pang TY. Increased paternal corticosterone exposure influences offspring behaviour and expression of urinary pheromones. BMC Biol 2023; 21:186. [PMID: 37667240 PMCID: PMC10478242 DOI: 10.1186/s12915-023-01678-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 08/07/2023] [Indexed: 09/06/2023] Open
Abstract
BACKGROUND Studies have shown that paternal stress prior to conception can influence the innate behaviours of their offspring. The evolutionary impacts of such intergenerational effects are therefore of considerable interest. Our group previously showed in a model of daily stress that glucocorticoid treatment of adult male mouse breeders prior to conception leads to increased anxiety-related behaviours in male offspring. Here, we aimed to understand the transgenerational effects of paternal stress exposure on the social behaviour of progeny and its potential influence on reproductive success. RESULTS We assessed social parameters including social reward, male attractiveness and social dominance, in the offspring (F1) and grand-offspring (F2). We report that paternal corticosterone treatment was associated with increased display of subordination towards other male mice. Those mice were unexpectedly more attractive to female mice while expressing reduced levels of the key rodent pheromone Darcin, contrary to its conventional role in driving female attraction. We investigated the epigenetic regulation of major urinary protein (Mup) expression by performing the first Oxford Nanopore direct methylation of sperm DNA in a mouse model of stress, but found no differences in Mup genes that could be attributed to corticosterone-treatment. Furthermore, no overt differences of the prefrontal cortex transcriptome were found in F1 offspring, implying that peripheral mechanisms are likely contributing to the phenotypic differences. Interestingly, no phenotypic differences were observed in the F2 grand-offspring. CONCLUSIONS Overall, our findings highlight the potential of moderate paternal stress to affect intergenerational (mal)adaptive responses, informing future studies of adaptiveness in rodents, humans and other species.
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Affiliation(s)
- Lucas B Hoffmann
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- Florey Department of Neuroscience and Mental Health, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, VIC, Australia
| | - Evangeline A McVicar
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- Department of Anatomy and Physiology, University of Melbourne, Parkville, VIC, Australia
| | - Rebekah V Harris
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- Department of Anatomy and Physiology, University of Melbourne, Parkville, VIC, Australia
| | - Coralina Collar-Fernández
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- Florey Department of Neuroscience and Mental Health, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, VIC, Australia
| | - Michael B Clark
- Centre for Stem Cell Systems, Department of Anatomy and Physiology, University of Melbourne, Parkville, VIC, Australia
| | - Anthony J Hannan
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- Florey Department of Neuroscience and Mental Health, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, VIC, Australia
- Department of Anatomy and Physiology, University of Melbourne, Parkville, VIC, Australia
| | - Terence Y Pang
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia.
- Florey Department of Neuroscience and Mental Health, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, VIC, Australia.
- Department of Anatomy and Physiology, University of Melbourne, Parkville, VIC, Australia.
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5
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Albery GF, Clutton-Brock TH, Morris A, Morris S, Pemberton JM, Nussey DH, Firth JA. Ageing red deer alter their spatial behaviour and become less social. Nat Ecol Evol 2022; 6:1231-1238. [PMID: 35864228 PMCID: PMC10859100 DOI: 10.1038/s41559-022-01817-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 05/27/2022] [Indexed: 01/19/2023]
Abstract
Social relationships are important to many aspects of animals' lives, and an individual's connections may change over the course of their lifespan. Currently, it is unclear whether social connectedness declines within individuals as they age, and what the underlying mechanisms might be, so the role of age in structuring animal social systems remains unresolved, particularly in non-primates. Here we describe senescent declines in social connectedness using 46 years of data in a wild, individually monitored population of a long-lived mammal (European red deer, Cervus elaphus). Applying a series of spatial and social network analyses, we demonstrate that these declines occur because of within-individual changes in social behaviour, with correlated changes in spatial behaviour (smaller home ranges and movements to lower-density, lower-quality areas). These findings demonstrate that within-individual socio-spatial behavioural changes can lead older animals in fission-fusion societies to become less socially connected, shedding light on the ecological and evolutionary processes structuring wild animal populations.
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Affiliation(s)
- Gregory F Albery
- Department of Biology, Georgetown University, Washington DC, USA.
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK.
- Wissenschaftskolleg zu Berlin, Berlin, Germany.
| | | | - Alison Morris
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK
| | - Sean Morris
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK
| | | | - Daniel H Nussey
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK
| | - Josh A Firth
- Department of Zoology, University of Oxford, Oxford, UK
- Merton College, University of Oxford, Oxford, UK
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6
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Strauss ED, Shizuka D. The ecology of wealth inequality in animal societies. Proc Biol Sci 2022; 289:20220500. [PMID: 35506231 PMCID: PMC9065979 DOI: 10.1098/rspb.2022.0500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Accepted: 03/23/2022] [Indexed: 11/30/2022] Open
Abstract
Individuals vary in their access to resources, social connections and phenotypic traits, and a central goal of evolutionary biology is to understand how this variation arises and influences fitness. Parallel research on humans has focused on the causes and consequences of variation in material possessions, opportunity and health. Central to both fields of study is that unequal distribution of wealth is an important component of social structure that drives variation in relevant outcomes. Here, we advance a research framework and agenda for studying wealth inequality within an ecological and evolutionary context. This ecology of inequality approach presents the opportunity to reintegrate key evolutionary concepts as different dimensions of the link between wealth and fitness by (i) developing measures of wealth and inequality as taxonomically broad features of societies, (ii) considering how feedback loops link inequality to individual and societal outcomes, (iii) exploring the ecological and evolutionary underpinnings of what makes some societies more unequal than others, and (iv) studying the long-term dynamics of inequality as a central component of social evolution. We hope that this framework will facilitate a cohesive understanding of inequality as a widespread biological phenomenon and clarify the role of social systems as central to evolutionary biology.
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Affiliation(s)
- Eli D. Strauss
- Department of Collective Behaviour, Max Planck Institute of Animal Behaviour, Konstanz, Germany
- Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA
- BEACON Center for the Study of Evolution in Action, Michigan State University, Lansing, MI, USA
| | - Daizaburo Shizuka
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA
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7
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Carlitz EHD, Lindholm AK, Gao W, Kirschbaum C, König B. Steroid hormones in hair and fresh wounds reveal sex specific costs of reproductive engagement and reproductive success in wild house mice (Mus musculus domesticus). Horm Behav 2022; 138:105102. [PMID: 34998227 DOI: 10.1016/j.yhbeh.2021.105102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 10/19/2021] [Accepted: 12/12/2021] [Indexed: 11/30/2022]
Abstract
Not only males but also females compete over reproduction. In a population of free-living house mice (Mus musculus domesticus), we analyzed how (metabolic) costs of aggressive interactions (reflected in fresh wounds and long-term corticosterone concentrations in hair) are predicted by individual reproductive physiology and reproductive success in males and females. Over eight years, we studied wounds and reproduction of more than 2800 adults under naturally varying environmental conditions and analyzed steroid hormones from more than 1000 hair samples. Hair corticosterone were higher and wounds more frequent in males than females. In males, wound occurrence increased with increasing breeding activity in the population, without affecting hair corticosterone levels. Unexpectedly, individual male reproductive success did not predict wounds, while hair corticosterone increased with increasing levels of hair testosterone and reproductive success. High corticosterone in hair of males might therefore reflect metabolic costs of fighting over reproduction. In females, hair corticosterone was generally lower than in males and high levels did not impede pregnancy. Reproductive investment (reflected in hair progesterone) was dissociated from reproductive success. Occasional wounds in females indicated individuals without recent reproductive success and revealed reproductive competition, presumably driven by instability in the social environment. In both sexes, corticosterone increased with age, but there was no evidence that received overt aggression, as indicated by wounds or elevated corticosterone, suppressed reproductive physiology. Our results diverge from laboratory findings and emphasize the need to also study animals in their natural environment in order to understand the complexity of their behavioral physiology.
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Affiliation(s)
- Esther H D Carlitz
- Department of Psychology, Biological Psychology, Technical University of Dresden, Dresden, Germany.
| | - Anna K Lindholm
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Wei Gao
- Department of Psychology, Biological Psychology, Technical University of Dresden, Dresden, Germany
| | - Clemens Kirschbaum
- Department of Psychology, Biological Psychology, Technical University of Dresden, Dresden, Germany
| | - Barbara König
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
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8
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Abstract
Dispersal is a critical process that shapes the structure of wild animal populations. In species that form multi‐level societies, natal dispersal might be social (associating with a different social community while remaining near the natal area), spatial (moving away from the natal area while continuing to associate with the same community) or both social and spatial (associating with a different community and moving away from the natal area). For such species, classical spatial measures of dispersal, such as distance moved, might not capture social dispersal. We examined dispersal outcomes for 67 male and 70 female giraffe calves over 7 years in a large, unfenced, ecologically heterogeneous landscape. We tested predictions about the influence of sex, food availability, low‐ and high‐impact human settlements, and local giraffe population density on social or spatial dispersal, dispersal distance, and age of dispersal. We found that dispersal is sex‐specific, with females being predominately philopatric. When dispersing, both sexes did so at a mean of 4 years of age. Most (69% of total) young males dispersed, with 84% of male dispersers associating with a different adult female social community than that of their mother, but one in four of these dispersers remained spatially near to their natal area. For adolescent males that dispersed socially but not spatially, overlapping female social communities may represent a potential pool of unrelated mating partners without the risks of travelling to unfamiliar areas. Just 26% of young females dispersed and half of these continued to associate with the adult female social community into which they were born, confirming the importance of maintaining ties among females from calf to adulthood. Furthermore, individuals born farther from high‐impact human settlements were more likely to spatially or socially‐and‐spatially disperse, move greater distances from their natal areas, and disperse at a younger age. Our study highlights the potential importance of social structure in dispersal decisions, and of tracking social structure when studying dispersal in multi‐level societies, as effective dispersal can be attained without large‐scale spatial displacements.
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Affiliation(s)
- Luca Börger
- Department of Biosciences, Swansea University, Swansea, UK
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9
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Chaine AS. Social Evolution: Big Benefits of BFFs. Curr Biol 2021; 31:R72-R74. [PMID: 33497633 DOI: 10.1016/j.cub.2020.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Having long-term familiar neighbors - rather than kin neighbors - can increase survival and double reproductive success in North American red squirrels. These benefits are so high they can slow senescence and may explain numerous social behaviors in this otherwise individualistic species.
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Affiliation(s)
- Alexis S Chaine
- Station d'Ecologie Théorique et Expérimentale du CNRS, UMR 5321, 2 route du CNRS, 09200 Moulis, France; Institute for Advanced Studies in Toulouse, 21 allée de Brienne, 31015 Toulouse, France.
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10
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Testard C, Larson SM, Watowich MM, Kaplinsky CH, Bernau A, Faulder M, Marshall HH, Lehmann J, Ruiz-Lambides A, Higham JP, Montague MJ, Snyder-Mackler N, Platt ML, Brent LJN. Rhesus macaques build new social connections after a natural disaster. Curr Biol 2021; 31:2299-2309.e7. [PMID: 33836140 DOI: 10.1016/j.cub.2021.03.029] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 01/04/2021] [Accepted: 03/09/2021] [Indexed: 01/05/2023]
Abstract
Climate change is increasing the frequency and intensity of weather-related disasters such as hurricanes, wildfires, floods, and droughts. Understanding resilience and vulnerability to these intense stressors and their aftermath could reveal adaptations to extreme environmental change. In 2017, Puerto Rico suffered its worst natural disaster, Hurricane Maria, which left 3,000 dead and provoked a mental health crisis. Cayo Santiago island, home to a population of rhesus macaques (Macaca mulatta), was devastated by the same storm. We compared social networks of two groups of macaques before and after the hurricane and found an increase in affiliative social connections, driven largely by monkeys most socially isolated before Hurricane Maria. Further analysis revealed monkeys invested in building new relationships rather than strengthening existing ones. Social adaptations to environmental instability might predispose rhesus macaques to success in rapidly changing anthropogenic environments.
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Affiliation(s)
- Camille Testard
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA, USA.
| | - Sam M Larson
- Department of Anthropology, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Cassandre H Kaplinsky
- Centre for Research in Evolutionary, Social and Interdisciplinary Anthropology, University of Roehampton, Roehampton, UK
| | - Antonia Bernau
- Centre for Research in Animal Behaviour, University of Exeter, Exeter, UK
| | - Matthew Faulder
- Centre for Research in Animal Behaviour, University of Exeter, Exeter, UK
| | - Harry H Marshall
- Department of Life Sciences, University of Roehampton, London, UK
| | - Julia Lehmann
- Department of Life Sciences, University of Roehampton, London, UK
| | - Angelina Ruiz-Lambides
- Carribean Primate Research Center-Cayo Santiago, University of Puerto Rico, Cayo Santiago Island, Puerto Rico
| | - James P Higham
- Department of Anthropology, New York University, New York, NY, USA
| | - Michael J Montague
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA, USA
| | - Noah Snyder-Mackler
- School of Life Sciences, Arizona State University, Tempe, AZ, USA; Center for Evolution and Medicine, Arizona State University, Tempe, AZ, USA
| | - Michael L Platt
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA, USA; Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA; Department of Marketing, University of Pennsylvania, Philadelphia, PA, USA
| | - Lauren J N Brent
- Centre for Research in Animal Behaviour, University of Exeter, Exeter, UK
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11
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Gerber N, Auclair Y, König B, Lindholm AK. Population Density and Temperature Influence the Return on Maternal Investment in Wild House Mice. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2020.602359] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
In mammals, reproduction is influenced by sexual competition, temperature and food availability and these factors might be crucial already during early life. Favorable early life environment and high maternal investment are expected to improve survival and reproduction. For example, in mammals, maternal investment via lactation predicts offspring growth. As body mass is often associated with fitness consequences, females have the potential to influence offspring fitness through their level of investment, which might interact with effects of population density and temperature. Here, we investigate the relationship between house mouse (Mus musculus domesticus) pup body mass at day 13 (used as approximation for weaning mass) and individual reproductive parameters, as well as longevity, under natural variation in population density and temperature (as approximation for season). Further, we assessed the extent to which mothers influence the body mass of their offspring until weaning. To do so, we analyzed life data of 384 house mice from a free-living wild commensal population that was not food limited. The mother’s contribution accounted for 49% of the variance in pup body mass. Further, we found a complex effect of population density, temperature and maternal investment on life-history traits related to fitness: shorter longevity with increasing pup body mass at day 13, delayed first reproduction of heavier pups when raised at warmer temperatures, and increased lifetime reproductive success for heavier pups at high densities. Our study shows that the effects of maternal investment are not independent of the effects of the environment. It thus highlights the importance of considering ecological conditions in combination with maternal effects to unravel the complexity of pup body mass on fitness measures.
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12
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The role of social structure and dynamics in the maintenance of endemic disease. Behav Ecol Sociobiol 2021; 75:122. [PMID: 34421183 PMCID: PMC8370858 DOI: 10.1007/s00265-021-03055-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 07/09/2021] [Accepted: 07/13/2021] [Indexed: 02/07/2023]
Abstract
Social interactions are required for the direct transmission of infectious diseases. Consequently, the social network structure of populations plays a key role in shaping infectious disease dynamics. A huge research effort has examined how specific social network structures make populations more (or less) vulnerable to damaging epidemics. However, it can be just as important to understand how social networks can contribute to endemic disease dynamics, in which pathogens are maintained at stable levels for prolonged periods of time. Hosts that can maintain endemic disease may serve as keystone hosts for multi-host pathogens within an ecological community, and also have greater potential to act as key wildlife reservoirs of agricultural and zoonotic diseases. Here, we examine combinations of social and demographic processes that can foster endemic disease in hosts. We synthesise theoretical and empirical work to demonstrate the importance of both social structure and social dynamics in maintaining endemic disease. We also highlight the importance of distinguishing between the local and global persistence of infection and reveal how different social processes drive variation in the scale at which infectious diseases appear endemic. Our synthesis provides a framework by which to understand how sociality contributes to the long-term maintenance of infectious disease in wildlife hosts and provides a set of tools to unpick the social and demographic mechanisms involved in any given host-pathogen system. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s00265-021-03055-8.
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13
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Evans JC, Lindholm AK, König B. Long-term overlap of social and genetic structure in free-ranging house mice reveals dynamic seasonal and group size effects. Curr Zool 2020; 67:59-69. [PMID: 33654491 PMCID: PMC7901755 DOI: 10.1093/cz/zoaa030] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 06/10/2020] [Indexed: 12/02/2022] Open
Abstract
Associating with relatives in social groups can bring benefits such as reduced risk of aggression and increased likelihood of cooperation. Competition among relatives over limited resources, on the other hand, can induce individuals to alter their patterns of association. Population density might further affect the costs and benefits of associating with relatives by altering resource competition or by changing the structure of social groups; preventing easy association with relatives. Consequently, the overlap between genetic and social structure is expected to decrease with increasing population size, as well as during times of increased breeding activity. Here, we use multi-layer network techniques to quantify the similarity between long-term, high resolution genetic, and behavioral data from a large population of free-ranging house mice (Mus musculus domesticus), studied over 10 years. We infer how the benefit of associating with genetically similar individuals might fluctuate in relation to breeding behavior and environmental conditions. We found a clear seasonal effect, with decreased overlap between social and genetic structure during summer months, characterized by high temperatures and high breeding activity. Though the effect of overall population size was relatively weak, we found a clear decrease in the overlap between genetic similarity and social associations within larger groups. As well as longer-term within-group changes, these results reveal population-wide short-term shifts in how individuals associate with relatives. Our study suggests that resource competition modifies the trade-off between the costs and benefits of interacting with relatives.
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Affiliation(s)
- Julian C Evans
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, Zurich, 8057, Switzerland
- Address correspondence to Julian C. Evans. E-mail:
| | - Anna K Lindholm
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, Zurich, 8057, Switzerland
| | - Barbara König
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, Zurich, 8057, Switzerland
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