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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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2
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Affiliation(s)
- Marcelo H. Cassini
- Laboratorio de Biología del Comportamiento IBYME CONICET Obligado 2490 Buenos Aires1429Argentina
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3
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Firman RC, Ottewell KM, Fisher DO, Tedeschi JN. Range-wide genetic structure of a cooperative mouse in a semi-arid zone: Evidence for panmixia. J Evol Biol 2019; 32:1014-1026. [PMID: 31211909 DOI: 10.1111/jeb.13498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 06/05/2019] [Accepted: 06/12/2019] [Indexed: 12/20/2022]
Abstract
Landscape topography and the mobility of individuals will have fundamental impacts on a species' population structure, for example by enhancing or reducing gene flow and therefore influencing the effective size and genetic diversity of the population. However, social organization will also influence population genetic structure. For example, species that live and breed in cooperative groups may experience high levels of inbreeding and strong genetic drift. The western pebble-mound mouse (Pseudomys chapmani), which occupies a highly heterogeneous, semi-arid landscape in Australia, is an enigmatic social mammal that has the intriguing behaviour of working cooperatively in groups to build permanent pebble mounds above a subterranean burrow system. Here, we used both nuclear (microsatellite) and mitochondrial (mtDNA) markers to analyse the range-wide population structure of western pebble-mound mice sourced from multiple social groups. We observed high levels of genetic diversity at the broad scale, very weak genetic differentiation at a finer scale and low levels of inbreeding. Our genetic analyses suggest that the western pebble-mound mouse population is both panmictic and highly viable. We conclude that high genetic connectivity across the complex landscape is a consequence of the species' ability to permeate their environment, which may be enhanced by "boom-bust" population dynamics driven by the semi-arid climate. More broadly, our results highlight the importance of sampling strategies to infer social structure and demonstrate that sociality is an important component of population genetic structure.
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Affiliation(s)
- Renée C Firman
- Centre for Evolutionary Biology, University of Western Australia, Crawley, Western Australia, Australia
| | - Kym M Ottewell
- Science and Conservation, Department of Biodiversity, Conservation and Attractions, Bentley Delivery Centre, Kensington, Western Australia, Australia
| | - Diana O Fisher
- School of Biological Sciences, University of Queensland, Brisbane, Queensland, Australia
| | - Jamie N Tedeschi
- Centre for Evolutionary Biology, University of Western Australia, Crawley, Western Australia, Australia
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Hayes GLT, Simmons LW, Dugand RJ, Mills HR, Roberts JD, Tomkins JL, Fisher DO. Male semelparity and multiple paternity confirmed in an arid‐zone dasyurid. J Zool (1987) 2019. [DOI: 10.1111/jzo.12672] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- G. L. T. Hayes
- School of Biological Sciences The University of Western Australia Crawley WA Australia
| | - L. W. Simmons
- School of Biological Sciences The University of Western Australia Crawley WA Australia
| | - R. J. Dugand
- School of Biological Sciences The University of Western Australia Crawley WA Australia
- School of Biological Sciences The University of Queensland Brisbane Qld Australia
| | - H. R. Mills
- Centre for Ecosystem Management School of Science Edith Cowan University Joondalup WA Australia
| | - J. D. Roberts
- School of Biological Sciences The University of Western Australia Crawley WA Australia
| | - J. L. Tomkins
- School of Biological Sciences The University of Western Australia Crawley WA Australia
| | - D. O. Fisher
- School of Biological Sciences The University of Queensland Brisbane Qld Australia
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Collett RA, Baker AM, Fisher DO. Prey productivity and predictability drive different axes of life-history variation in carnivorous marsupials. Proc Biol Sci 2018; 285:rspb.2018.1291. [PMID: 30381377 DOI: 10.1098/rspb.2018.1291] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Accepted: 10/10/2018] [Indexed: 11/12/2022] Open
Abstract
Variation in life-history strategies has usually been characterized as a single fast-slow continuum of life-history variation, in which mean lifespan increases with age at maturity as reproductive output at each breeding event declines. Analyses of plants and animals suggest that strategies of reproductive timing can vary on an independent axis, with iteroparous species at one extreme and semelparous species at the other. Insectivorous marsupials in the Family Dasyuridae have an unusually wide range of life-history strategies on both purported axes. We test and confirm that reproductive output and degree of iteroparity are independent in females across species. Variation in reproductive output per episode is associated with mean annual rainfall, which predicts food availability. Position on the iteroparity-semelparity axis is not associated with annual rainfall, but species in regions of unpredictable rainfall have longer maximum lifespans, more potential reproductive events per year, and longer breeding seasons. We suggest that these two axes of life-history variation arise because reproductive output is limited by overall food availability, and selection for high offspring survival favours concentrated breeding in seasonal environments. Longer lifespans are favoured when reproductive opportunities are dispersed over longer periods in environments with less predictable food schedules.
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Affiliation(s)
- Rachael A Collett
- School of Biological Sciences, University of Queensland, Brisbane, Queensland 4072, Australia
| | - Andrew M Baker
- School of Earth, Environmental and Biological Sciences, Queensland University of Technology, Brisbane, Queensland 4000, Australia
| | - Diana O Fisher
- School of Biological Sciences, University of Queensland, Brisbane, Queensland 4072, Australia
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6
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Wheatley R, Niehaus AC, Fisher DO, Wilson RS. Ecological context and the probability of mistakes underlie speed choice. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13036] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rebecca Wheatley
- School of Biological Sciences University of Queensland Brisbane Australia
| | - Amanda C. Niehaus
- School of Biological Sciences University of Queensland Brisbane Australia
| | - Diana O. Fisher
- School of Biological Sciences University of Queensland Brisbane Australia
| | - Robbie S. Wilson
- School of Biological Sciences University of Queensland Brisbane Australia
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Smith GC, Means K, Churchill S. Aspects of the ecology of the Atherton antechinus (Antechinus godmani) living in sympatry with the rusty antechinus (A. adustus) in the Wet Tropics, Queensland – a trapping and radio-tracking study. AUSTRALIAN MAMMALOGY 2018. [DOI: 10.1071/am16050] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The ecology of the geographically restricted Atherton antechinus (Antechinus godmani) is poorly known. This trapping and radio-tracking study provides historical baseline information on its ecology. The Atherton antechinus foraged primarily at night in deep leaf litter and rotting logs. The sympatric, smaller rusty antechinus (A. adustus) was arboreal and active both day and night, suggesting resource partitioning between species. The diet of the Atherton antechinus included a significant component of beetles, centipedes, spiders, cockroaches, crickets, and ants; minor items included a frog and a skink. Declines in male condition of both antechinus species occurred in June–July. Free-living young of the rusty and the Atherton antechinus were first trapped in November and January, respectively. Minimum convex polygon home ranges for the Atherton antechinus were 2.5–5.8 ha for males and 3.6 ha for a female. Multiple nest sites were used by individual Atherton antechinuses with simultaneous sharing of nests observed only between sexes. A home range of a single female was overlapped by the home ranges of numerous males. The Atherton antechinus prefers contiguous areas of wet tropical upland rainforest with old-growth characteristics, including large old trees for nest sites, fallen woody debris and deep leaf litter for foraging. The impacts of climate change could be devastating.
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Torpor in free-ranging antechinus: does it increase fitness? Naturwissenschaften 2014; 101:105-14. [PMID: 24441710 DOI: 10.1007/s00114-013-1136-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 12/18/2013] [Accepted: 12/22/2013] [Indexed: 10/25/2022]
Abstract
Antechinus are small, insectivorous, heterothermic marsupial mammals that use torpor from late summer to early winter and reproduce once a year in late winter/early spring. Males die after mating, most females produce only a single litter, but some survive a second winter and produce another litter. As it is not known how these females manage to survive the second winter after the energetically demanding reproductive period and then reproduce a second time, we aimed to provide the first data on thermal biology of free-ranging antechinus by using temperature telemetry. Male Antechinus stuartii and Antechinus flavipes rarely entered torpor in autumn/early winter in the wild, expressing only shallow bouts of <2 h. Female A. stuartii used torpor extensively, employing bouts up to 16.7 h with body temperatures as low as 17.8 °C. Interestingly, although first and second year females used similar torpor patterns, torpor occurrence was almost twofold in second year (93 % of days) than first year females (49 %), and the proportion of the overall monitoring period animals spent torpid was 3.2-fold longer in the former with a corresponding shorter activity period. Our study suggests that intensive use of torpor is crucial for second year females for autumn and winter survival and production of a second litter. We provide the first evidence of an age-related pattern in daily torpor expression in free-ranging mammals and show that torpor use is a complex process that is affected not only by the current energy availability and thermal conditions but also by the reproductive history and age of individuals.
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Sperm competition drives the evolution of suicidal reproduction in mammals. Proc Natl Acad Sci U S A 2013; 110:17910-4. [PMID: 24101455 DOI: 10.1073/pnas.1310691110] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Suicidal reproduction (semelparity) has evolved in only four genera of mammals. In these insectivorous marsupials, all males die after mating, when failure of the corticosteroid feedback mechanism elevates stress hormone levels during the mating season and causes lethal immune system collapse (die-off). We quantitatively test and resolve the evolutionary causes of this surprising and extreme life history strategy. We show that as marsupial predators in Australia, South America, and Papua New Guinea diversified into higher latitudes, seasonal predictability in abundance of their arthropod prey increased in multiple habitats. More-predictable prey peaks were associated with shorter annual breeding seasons, consistent with the suggestion that females accrue fitness benefits by timing peak energy demands of reproduction to coincide with maximum food abundance. We demonstrate that short mating seasons intensified reproductive competition between males, increasing male energy investment in copulations and reducing male postmating survival. However, predictability of annual prey cycles alone does not explain suicidal reproduction, because unlike insect abundance, peak ovulation dates in semelparous species are often synchronized to the day among years, triggered by a species-specific rate of change of photoperiod. Among species with low postmating male survival, we show that those with suicidal reproduction have shorter mating seasons and larger testes relative to body size. This indicates that lethal effort is adaptive in males because females escalate sperm competition by further shortening and synchronizing the annual mating period and mating promiscuously. We conclude that precopulatory sexual selection by females favored the evolution of suicidal reproduction in mammals.
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10
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Affiliation(s)
- C. A. Toth
- School of Biological Sciences University of Auckland Auckland New Zealand
| | - S. Parsons
- School of Biological Sciences University of Auckland Auckland New Zealand
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11
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Robert K, Garant D, Vander Wal E, Pelletier F. Context-dependent social behaviour: testing the interplay between season and kinship with raccoons. J Zool (1987) 2013. [DOI: 10.1111/jzo.12027] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- K. Robert
- Département de biologie; Université de Sherbrooke; Sherbrooke QC Canada
| | - D. Garant
- Département de biologie; Université de Sherbrooke; Sherbrooke QC Canada
| | - E. Vander Wal
- Département de biologie; Université de Sherbrooke; Sherbrooke QC Canada
| | - F. Pelletier
- Canada Research Chair in Evolutionary Demography and Conservation; Département de biologie; Université de Sherbrooke; Sherbrooke QC Canada
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12
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Banks SC, Lindenmayer DB, Wood JT, McBurney L, Blair D, Blyton MDJ. Can individual and social patterns of resource use buffer animal populations against resource decline? PLoS One 2013; 8:e53672. [PMID: 23320100 PMCID: PMC3539978 DOI: 10.1371/journal.pone.0053672] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Accepted: 12/03/2012] [Indexed: 11/30/2022] Open
Abstract
Species in many ecosystems are facing declines of key resources. If we are to understand and predict the effects of resource loss on natural populations, we need to understand whether and how the way animals use resources changes under resource decline. We investigated how the abundance of arboreal marsupials varies in response to a critical resource, hollow-bearing trees. Principally, we asked what mechanisms mediate the relationship between resources and abundance? Do animals use a greater or smaller proportion of the remaining resource, and is there a change in cooperative resource use (den sharing), as the availability of hollow trees declines? Analyses of data from 160 sites surveyed from 1997 to 2007 showed that hollow tree availability was positively associated with abundance of the mountain brushtail possum, the agile antechinus and the greater glider. The abundance of Leadbeater’s possum was primarily influenced by forest age. Notably, the relationship between abundance and hollow tree availability was significantly less than 1∶1 for all species. This was due primarily to a significant increase by all species in the proportional use of hollow-bearing trees where the abundance of this resource was low. The resource-sharing response was weaker and inconsistent among species. Two species, the mountain brushtail possum and the agile antechinus, showed significant but contrasting relationships between the number of animals per occupied tree and hollow tree abundance. The discrepancies between the species can be explained partly by differences in several aspects of the species’ biology, including body size, types of hollows used and social behaviour as it relates to hollow use. Our results show that individual and social aspects of resource use are not always static in response to resource availability and support the need to account for dynamic resource use patterns in predictive models of animal distribution and abundance.
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Affiliation(s)
- Sam C Banks
- The Fenner School of Environment and Society, The Australian National University, Canberra, Australian Capital Territory, Australia.
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