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Evans JC, Lindholm AK, König B. Family dynamics reveal that female house mice preferentially breed in their maternal community. Behav Ecol 2021. [DOI: 10.1093/beheco/arab128] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Whether females breed in their natal group is an important factor in the evolution of extended families in animal sociality. Breeding in natal groups comes with costs and benefits, depending on group size and presence of older relatives, including mothers. Studying the consequences of breeding in the natal versus another group provides insight into the decisions and trade-offs governing the formation and structure of family groups. We investigated the family dynamics of a population of free-ranging commensal house mice. Using dynamic community detection on long-term datasets, we determined which females first bred in their natal group. We then looked at how this influenced breeding success. We found most females (77%) exhibited strong philopatry, breeding in their natal groups. Breeding elsewhere was only somewhat predictable at very large and very small group sizes. Despite their philopatric preference, breeding elsewhere made no difference in how quickly and successfully a female bred. However, presence of their mother did lead females to breed sooner when born during high breeding activity, when competition over reproduction is high. Based on these results, potential loss of reproductive success from leaving the natal group does not seem to be the main driver of philopatry in female house mice. The effect of the presence of mothers suggests that benefiting from established social connections promotes breeding in the natal group. Mothers providing benefits also implies a lack of conflict between generations, which will be important for the development of stable social groups.
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Affiliation(s)
- Julian C Evans
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Anna K Lindholm
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Barbara König
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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2
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Mermoz ME, Villarruel C, de la Colina A, Mahler B. Fledgling sex-ratio is biased towards the helping sex in a Neotropical cooperative breeder, the brown-and-yellow marshbird (Pseudoleistes virescens). BEHAVIOUR 2021. [DOI: 10.1163/1568539x-bja10061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
In many cooperatively breeding species, helpers increase the breeding success of their parents. The repayment hypothesis predicts a skewed sex-ratio towards the helping sex at population level; at individual level bias would increase in broods attended by a smaller number of helpers. We studied a brown-and-yellow marshbird (Pseudoleistes virescens) population during 11 breeding seasons. We found that 90% of helpers were males and that they increased nestling survival, although this effect disappeared in presence of parasitic shiny cowbirds. Helpers sometimes helped at nests of adults other than their parents. Population sex-ratio of fledglings was highly skewed towards males (1.4:1). At individual level, male-biased sex-ratio of fledglings was more pronounced early in the season and increased with brood losses but was not affected by number of helpers. Marshbirds feed at communal areas so retaining helpers would not be costly. Therefore, a general skew towards males might be the best adaptive strategy.
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Affiliation(s)
- Myriam E. Mermoz
- Instituto de Ecología, Genética, y Evolución de Buenos Aires (UBA-CONICET), Intendente Güiraldes 2160 — Ciudad Universitaria — C1428EGA, CABA, Argentina
- Departamento de Ecología, Genética, y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Güiraldes 2160 — C1428EGA Ciudad Universitaria, CABA, Argentina
| | - Cecilia Villarruel
- Departamento de Ecología, Genética, y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Güiraldes 2160 — C1428EGA Ciudad Universitaria, CABA, Argentina
- Current address: Instituto de Fisiología, Biología Molecular y Neurociencias (UBA-CONICET), Intendente Güiraldes 2160 — C1428EGA Ciudad Universitaria, CABA, Argentina
| | - Alicia de la Colina
- Instituto de Ecología, Genética, y Evolución de Buenos Aires (UBA-CONICET), Intendente Güiraldes 2160 — Ciudad Universitaria — C1428EGA, CABA, Argentina
- Current address: Departamento de Conservación e Investigación, Fundación Temaikèn — B1625 Escobar, Prov. de Buenos Aires, Argentina
| | - Bettina Mahler
- Instituto de Ecología, Genética, y Evolución de Buenos Aires (UBA-CONICET), Intendente Güiraldes 2160 — Ciudad Universitaria — C1428EGA, CABA, Argentina
- Departamento de Ecología, Genética, y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Intendente Güiraldes 2160 — C1428EGA Ciudad Universitaria, CABA, Argentina
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Liu T, Xu Y, Mo B, Shi J, Cheng Y, Zhang W, Lei F. Home range size and habitat use of the blue-crowned laughingthrush during the breeding season. PeerJ 2020; 8:e8785. [PMID: 32341888 PMCID: PMC7182022 DOI: 10.7717/peerj.8785] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 02/22/2020] [Indexed: 11/20/2022] Open
Abstract
The home range size and habitat use of the blue-crowned laughingthrush (Garrulax courtoisi, hereafter BCLT), a critically endangered, subtropical, cooperative-breeding bird species in southeast China, were studied during its breeding period using radio telemetry at different sites during 3 consecutive years (2016-18, from May to June of each year). A total of 17 birds (12 males, four females, and one of unknown sex) were tagged, and a total 1515 locations (mean ± se = 89.12 ± 11.42) were obtained over 54 days of tracking. The average 100% minimum convex polygon (MCP) home range size was 10.05 ± 1.17 ha, and the estimated KDE core area (fiexed kernel density estimator, KDE) size was 7.84 ± 1.18 ha. According to the Wilcoxon rank sum tests, both the 100% MCP and KDE core area size of males did not significantly differ from those of females. There were no significant differences in the 100% MCP or KDE core area sizes of the three breeding sites. The available habitats in the breeding sites included water areas, shrubs, grass plots, woodland, residential areas, vegetable field, farmland, and sandy beaches; among them, only woodland was significantly preferred by BCLTs. Woodland (average use ratio was 45.86 ± 1.74%) was strongly preferred by BCLTs for nesting, foraging and roosting. Shrubs/grass plots (24.72 ± 3.39%) and vegetable plots (11.80 ± 1.83%) were used relatively more often than the other habitats, except woodland, since shrubs were always used as perches, and vegetable plots were rich in food resources. Vertically, the canopy layer was used most often from April to June, but it was used most in May when the birds were hatching and brooding. This result indicates that BCLT is predominantly active in the upper strata during the breeding season. In addition, broadleaved trees within or adjacent to villages were important activity areas for the breeding birds; protection and management measures should be increased in these areas.
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Affiliation(s)
- Tao Liu
- College of Forestry, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Yongtao Xu
- College of Forestry, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Bai Mo
- College of Forestry, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Jinze Shi
- College of Forestry, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Yachang Cheng
- Department of Migration, Max Planck Institute of Animal Behavior, Radolfzell, Germany.,University of Konstanz, Department of Biology, Konstanz, Germany
| | - Weiwei Zhang
- College of Forestry, Jiangxi Agricultural University, Nanchang, Jiangxi, China
| | - Fumin Lei
- Institute of Zoology, Chinese Academy of Sciences, Beijing, China
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Nomano FY, Savage JL, Browning LE, Griffith SC, Russell AF. Breeding Phenology and Meteorological Conditions Affect Carer Provisioning Rates and Group-Level Coordination in Cooperative Chestnut-Crowned Babblers. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Brandl HB, Griffith SC, Farine DR, Schuett W. Wild zebra finches that nest synchronously have long-term stable social ties. J Anim Ecol 2019; 90:76-86. [PMID: 31407336 DOI: 10.1111/1365-2656.13082] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 06/14/2019] [Indexed: 11/26/2022]
Abstract
Many animals live and breed in colonies, and yet, with just a few exceptions, the value of the social bonds between colony members has rarely been examined. Social ties are important for group coordination at collective tasks, and social coordination can facilitate synchronized reproduction among colony members. Synchronized reproduction in turn can amplify the benefits of coloniality, such as social foraging and predator avoidance. We conducted a field study to investigate whether synchronized reproduction among individuals in replicated colonies is linked to the strength of their social bond, and whether these strong bonds are maintained beyond the reproductive period. We PIT-tagged wild zebra finches (Taeniopygia guttata), monitoring their reproduction and social foraging over two consecutive years. We then used social network analysis to characterize the strength of social bonds among birds in the population. We show that birds that are more synchronized in their reproductive timing (and breed in the same colony) had significantly stronger social ties both during and after reproduction than expected by chance. Our long-term sampling also revealed that the strong social ties between synchronized breeders were carried over across years. Our study reveals a strong correspondence between synchronized breeding and the social structure of the breeding colony. This suggests that the synchrony between pairs is not a simple process based on opportunity, but a mechanism underpinned by more complex sociality, which could be carried over to other behavioural contexts. The maintenance of cross-contextual social ties across years suggests that social structure could have extensive consequences on the overall life history of individuals in addition to playing a key role for the reproductive dynamics of colonial breeders.
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Affiliation(s)
- Hanja B Brandl
- Institute of Zoology, Universität Hamburg, Hamburg, Germany
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
- School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, Australia
- Department of Collective Behavior, Max Planck Institute of Animal Behavior, Konstanz, Germany
- Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Simon C Griffith
- Department of Biological Sciences, Macquarie University, Sydney, NSW, Australia
- School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, Australia
| | - Damien R Farine
- Department of Collective Behavior, Max Planck Institute of Animal Behavior, Konstanz, Germany
- Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany
- Department of Biology, University of Konstanz, Konstanz, Germany
- Edward Grey Institute of Field Ornithology, Department of Zoology, University of Oxford, Oxford, UK
| | - Wiebke Schuett
- Institute of Zoology, Universität Hamburg, Hamburg, Germany
- School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, Australia
- School of Life Sciences, University of Sussex, Brighton, UK
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6
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Rosenbaum S, Gettler LT. With a little help from her friends (and family) part I: the ecology and evolution of non-maternal care in mammals. Physiol Behav 2019; 193:1-11. [PMID: 29933836 DOI: 10.1016/j.physbeh.2017.12.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Revised: 11/27/2017] [Accepted: 12/20/2017] [Indexed: 10/28/2022]
Abstract
In the class Mammalia, most young are cared for exclusively by their mothers. In species where mothers receive help, however, non-maternal caregivers may play a crucial role in development and life history trajectories. In turn, recipients of such care may have important impacts on caregivers of all types. In Part I of this overview, we briefly review the evolutionary barriers to widespread non-maternal care in mammals, and explain why the exceptions are of particular theoretical importance. We also summarize the current understanding of the selective forces leading to non-maternal care, and the taxa and types of caretakers amongst which it occurs. Finally, we argue for a fresh look at the categorization schemes that have traditionally been used to separate various types of mammalian non-maternal caregivers. This two-part introduction is aimed at scientists from multiple disciplines who study diverse organismal systems. It draws from the social and biological sciences literatures to provide an overview of this special issue of Physiology and Behavior's suite of methodological offerings and theoretical underpinnings.
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Affiliation(s)
- Stacy Rosenbaum
- Department of Anthropology, Northwestern University, Evanston, IL, United States; Davee Center for Epidemiology and Endocrinology, Lincoln Park Zoo, Chicago, IL, United States.
| | - Lee T Gettler
- Department of Anthropology, University of Notre Dame, Notre Dame, IN, United States; The Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, United States
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7
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Kramer J, Meunier J. The other facets of family life and their role in the evolution of animal sociality. Biol Rev Camb Philos Soc 2019; 94:199-215. [PMID: 29989333 DOI: 10.1111/brv.12443] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Revised: 06/12/2018] [Accepted: 06/15/2018] [Indexed: 02/06/2023]
Abstract
Family life forms an integral part of the life history of species across the animal kingdom and plays a crucial role in the evolution of animal sociality. Our current understanding of family life, however, is almost exclusively based on studies that (i) focus on parental care and associated family interactions (such as those arising from sibling rivalry and parent-offspring conflict), and (ii) investigate these phenomena in the advanced family systems of mammals, birds, and eusocial insects. Here, we argue that these historical biases have fostered the neglect of key processes shaping social life in ancestral family systems, and thus profoundly hamper our understanding of the (early) evolution of family life. Based on a comprehensive survey of the literature, we first illustrate that the strong focus on parental care in advanced social systems has deflected scrutiny of other important social processes such as sibling cooperation, parent-offspring competition and offspring assistance. We then show that accounting for these neglected processes - and their changing role over time - could profoundly alter our understanding of the origin and subsequent evolution of family life. Finally, we outline how this 'diachronic' perspective on the evolution of family living provides novel insights into general processes driving the evolution of animal sociality. Overall, we infer that the explicit consideration of thus-far neglected facets of family life, together with their study across the whole diversity of family systems, are crucial to advance our understanding of the processes that shape the evolution of social life.
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Affiliation(s)
- Jos Kramer
- Department of Plant and Microbial Biology (IPMB), University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland
| | - Joël Meunier
- Institut de Recherche sur la Biologie de l'Insecte (IRBI), UMR 726, CNRS, Université de Tours, Avenue Monge, 37200 Tours, France
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8
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Leighton GM. Cooperative breeding influences the number and type of vocalizations in avian lineages. Proc Biol Sci 2018; 284:rspb.2017.1508. [PMID: 29187625 DOI: 10.1098/rspb.2017.1508] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 10/25/2017] [Indexed: 11/12/2022] Open
Abstract
Although communicative complexity is often predicted to correlate with social complexity in animal societies, few studies have employed large-scale comparative analyses to test whether socially complex species have more complex systems of communication. I tested this social complexity hypothesis in birds (Class: Aves) using the large amount of natural history information that describes both vocal repertoire and social system in these species. To do so, I marshalled data from primary and secondary records of avian vocal repertoires (n = 253), and for each of the species in the dataset I recorded the reported repertoire size and associated species information. Using phylogenetic comparative methods, I found that cooperative breeding was a strong and repeatable predictor of vocal repertoire size, while other social variables, e.g. group size and group stability, had little or no influence on repertoire size. Importantly, repertoire sizes expanded concurrently with the evolution of cooperative breeding, suggesting a direct link between these two traits. Cooperatively breeding species devoted significantly more of their repertoire to contact calls and alarm calls. Overall, these results therefore lend support to the hypothesis that social complexity via behavioural coordination leads to increases in vocal complexity.
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Affiliation(s)
- Gavin M Leighton
- Department of Neurobiology and Behavior, Cornell University, 215 Tower Road, Ithaca, NY 14850, USA .,Cornell Laboratory of Ornithology, Cornell University, 159 Sapsucker Woods, Ithaca, NY 14850, USA
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9
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10
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Savage JL, Browning LE, Manica A, Russell AF, Johnstone RA. Turn-taking in cooperative offspring care: by-product of individual provisioning behavior or active response rule? Behav Ecol Sociobiol 2017; 71:162. [PMID: 29081573 PMCID: PMC5644705 DOI: 10.1007/s00265-017-2391-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 09/28/2017] [Accepted: 09/29/2017] [Indexed: 11/29/2022]
Abstract
Abstract For individuals collaborating to rear offspring, effective organization of resource delivery is difficult because each carer benefits when the others provide a greater share of the total investment required. When investment is provided in discrete events, one possible solution is to adopt a turn-taking strategy whereby each individual reduces its contribution rate after investing, only increasing its rate again once another carer contributes. To test whether turn-taking occurs in a natural cooperative care system, here we use a continuous time Markov model to deduce the provisioning behavior of the chestnut-crowned babbler (Pomatostomus ruficeps), a cooperatively breeding Australian bird with variable number of carers. Our analysis suggests that turn-taking occurs across a range of group sizes (2–6), with individual birds being more likely to visit following other individuals than to make repeat visits. We show using a randomization test that some of this apparent turn-taking arises as a by-product of the distribution of individual inter-visit intervals (“passive” turn-taking) but that individuals also respond actively to the investment of others over and above this effect (“active” turn-taking). We conclude that turn-taking in babblers is a consequence of both their individual provisioning behavior and deliberate response rules, with the former effect arising through a minimum interval required to forage and travel to and from the nest. Our results reinforce the importance of considering fine-scale investment dynamics when studying parental care and suggest that behavioral rules such as turn-taking may be more common than previously thought. Significance statement Caring for offspring is a crucial stage in the life histories of many animals and often involves conflict as each carer typically benefits when others contribute a greater share of the work required. One way to resolve this conflict is to monitor when other carers contribute and adopt a simple “turn-taking” rule to ensure fairness, but natural parental care has rarely been studied in sufficient detail to identify such rules. Our study investigates whether cooperatively breeding chestnut-crowned babblers “take turns” delivering food to offspring, and (if so) whether this a deliberate strategy or simply a by-product of independent care behavior. We find that babblers indeed take turns and conclude that part of the observed turn-taking is due to deliberate responsiveness, with the rest arising from the species’ breeding ecology. Electronic supplementary material The online version of this article (10.1007/s00265-017-2391-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- James L Savage
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ UK.,Behavioural Ecology Group, Department of Animal Sciences, Wageningen University, De Elst 1, 6708 WD Wageningen, The Netherlands.,School of Biological, Earth, and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork, T23 TK30 Ireland
| | - Lucy E Browning
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ UK.,Fowlers Gap Arid Zone Research Station, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, 2052 NSW Australia
| | - Andrea Manica
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ UK
| | - Andrew F Russell
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Tremough Campus, Penryn, TR10 9FE UK
| | - Rufus A Johnstone
- Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ UK
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Kramer J, Körner M, Diehl JMC, Scheiner C, Yüksel‐Dadak A, Christl T, Kohlmeier P, Meunier J. When earwig mothers do not care to share: Parent–offspring competition and the evolution of family life. Funct Ecol 2017. [DOI: 10.1111/1365-2435.12915] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jos Kramer
- Zoological InstituteEvolutionary BiologyJohannes Gutenberg University Mainz Germany
- Department of Plant and Microbial BiologyUniversity of Zürich Zürich Switzerland
| | - Maximilian Körner
- Zoological InstituteEvolutionary BiologyJohannes Gutenberg University Mainz Germany
| | - Janina M. C. Diehl
- Zoological InstituteEvolutionary BiologyJohannes Gutenberg University Mainz Germany
| | - Christine Scheiner
- Zoological InstituteEvolutionary BiologyJohannes Gutenberg University Mainz Germany
| | - Aytül Yüksel‐Dadak
- Zoological InstituteEvolutionary BiologyJohannes Gutenberg University Mainz Germany
| | - Teresa Christl
- Zoological InstituteEvolutionary BiologyJohannes Gutenberg University Mainz Germany
| | - Philip Kohlmeier
- Zoological InstituteEvolutionary BiologyJohannes Gutenberg University Mainz Germany
| | - Joël Meunier
- Zoological InstituteEvolutionary BiologyJohannes Gutenberg University Mainz Germany
- Institut de Recherche sur la Biologie de l'InsecteUMR 7261CNRS/Université François‐Rabelais Tours France
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12
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Stroeymeyt N, Joye P, Keller L. Polydomy enhances foraging performance in ant colonies. Proc Biol Sci 2017; 284:20170269. [PMID: 28446699 PMCID: PMC5413928 DOI: 10.1098/rspb.2017.0269] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 03/21/2017] [Indexed: 11/12/2022] Open
Abstract
Collective foraging confers benefits in terms of reduced predation risk and access to social information, but it heightens local competition when resources are limited. In social insects, resource limitation has been suggested as a possible cause for the typical decrease in per capita productivity observed with increasing colony size, a phenomenon known as Michener's paradox. Polydomy (distribution of a colony's brood and workers across multiple nests) is believed to help circumvent this paradox through its positive effect on foraging efficiency, but there is still little supporting evidence for this hypothesis. Here, we show experimentally that polydomy enhances the foraging performance of food-deprived Temnothorax nylanderi ant colonies via several mechanisms. First, polydomy influences task allocation within colonies, resulting in faster retrieval of protein resources. Second, communication between sister nests reduces search times for far away resources. Third, colonies move queens, brood and workers across available nest sites in response to spatial heterogeneities in protein and carbohydrate resources. This suggests that polydomy represents a flexible mechanism for space occupancy, helping ant colonies adjust to the environment.
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Affiliation(s)
- N Stroeymeyt
- Department of Ecology and Evolution, Biophore, UNIL-Sorge, University of Lausanne, 1015 Lausanne, Switzerland
| | - P Joye
- Department of Ecology and Evolution, Biophore, UNIL-Sorge, University of Lausanne, 1015 Lausanne, Switzerland
| | - L Keller
- Department of Ecology and Evolution, Biophore, UNIL-Sorge, University of Lausanne, 1015 Lausanne, Switzerland
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Chappell MA, Buttemer WA, Russell AF. Energetics of communal roosting in chestnut-crowned babblers: implications for group dynamics and breeding phenology. J Exp Biol 2016; 219:3321-3328. [DOI: 10.1242/jeb.144972] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 08/15/2016] [Indexed: 01/22/2023]
Abstract
ABSTRACT
For many endotherms, communal roosting saves energy in cold conditions, but how this might affect social dynamics or breeding phenology is not well understood. Using chestnut-crowned babblers (Pomatostomus ruficeps), we studied the effects of nest use and group size on roosting energy costs. These 50 g cooperatively breeding passerine birds of outback Australia breed from late winter to early summer and roost in huddles of up to 20 in single-chambered nests. We measured babbler metabolism at three ecologically relevant temperatures: 5°C (similar to minimum nighttime temperatures during early breeding), 15°C (similar to nighttime temperatures during late breeding) and 28°C (thermal neutrality). Nest use alone had modest effects: even for solitary babblers at 5°C, it reduced nighttime energy expenditures by <15%. However, group-size effects were substantial, with savings of up to 60% in large groups at low temperatures. Babblers roosting in groups of seven or more at 5°C, and five or more at 15°C, did not need to elevate metabolic rates above basal levels. Furthermore, even at 28°C (thermoneutral for solitary babblers), individuals in groups of four or more had 15% lower basal metabolic rate than single birds, hinting that roosting in small groups is stressful. We suggest that the substantial energy savings of communal roosting at low temperatures help explain why early breeding is initiated in large groups and why breeding females, which roost alone and consequently expend 120% more energy overnight than other group members, suffer relatively higher mortality than communally roosting group mates.
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Affiliation(s)
- Mark A. Chappell
- Department of Biology, University of California, Riverside, Riverside, CA 92521, USA
| | - William A. Buttemer
- School of Biological Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia
- Centre for Integrative Ecology, Deakin University, Geelong, Victoria 3217, Australia
| | - Andrew F. Russell
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn, Cornwall TR10 9FE, UK
- Fowlers Gap Arid Zone Research Station, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
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