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Sex-specific effects of capital resources on reproductive timing and success in red squirrels

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Abstract

Reproduction is an energetically expensive activity for both sexes. However, if males and females differ in their annual timing of reproduction, such that peak investment for one sex occurs during a more resource-limited period, there is an opportunity for sex-specific selection to act on the acquisition of energetic resources. Both male and female North American red squirrels (Tamiasciurus hudsonicus) cache conifer cones, although males typically have larger caches than females. Peak energetic investment in reproduction occurs for males during the mating season in winter and early spring (when squirrels rely almost exclusively on cached resources) and for females during lactation (which can align with fresh food availability). We provide evidence that suggests sex differences in cache size are likely driven by a stronger positive connection between cached resources and components of fitness for males than for females. Specifically, males with larger caches have greater siring success than males with smaller caches, whereas for females, only early breeding females experience a positive effect of cache size on the number of recruits produced. We also show that males sire pups and females give birth earlier in the year if they have larger caches compared with squirrels of the same sex with smaller caches. Sexual selection can thus extend beyond traits directly connected to mating behavior, and can act on traits related to acquiring resources needed to fuel reproduction that are expressed months or years in advance of breeding efforts.

Significance statement

The timing and energetic requirements of reproduction are often different for males and females which could drive different life history strategies between the sexes. Red squirrels in the southwest Yukon, Canada cache white spruce cones in autumn, which serve as their primary food source until fresh food becomes available during summer. We measured the size of squirrel caches and subsequently monitored their reproduction to test whether the influence of stored food differs for males and females. We confirmed that males have larger caches than females and show that this is likely driven by a stronger positive association of cache size and components of fitness for males than for females. These findings highlight that the strength of selection can differ on the homologous traits of males and females leading to sex-specific extended phenotypes.

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Data availability

Data available from the Dryad Digital Repository: doi:10.5061/dryad.73n5tb30z.

References

  • Archibald DW, Fletcher QE, Boutin S, McAdam AG, Speakman JR, Humphries MM (2013) Sex-specific hoarding behavior in North American red squirrels (Tamiasciurus hudsonicus). J Mammal 94:761–770

    Article  Google Scholar 

  • Bates D, Maechler M, Bolker B, Walker S (2015) Fitting linear mixed-effects models using lme4. J Stat Softw 67:1–48

    Article  Google Scholar 

  • Beck CA, Bowen WD, Iverson SJ (2003) Sex differences in the seasonal patterns of energy storage and expenditure in a phocid seal. J Anim Ecol 72:280–291

    Article  Google Scholar 

  • Berteaux D, Boutin S (2000) Breeding dispersal in female North American red squirrels. Ecology 81:1311–1326

    Article  Google Scholar 

  • Boutin S (1990) Food supplementation experiments with terrestrial vertebrates: patterns, problems, and the future. Can J Zool 68:203–220

    Article  Google Scholar 

  • Boutin S, Larsen KW (1993) Does food availability affect growth and survival of males and females differently in a promiscuous small mammal, Tamiasciurus hudsonicus? J Anim Ecol 62:364–370

    Article  Google Scholar 

  • Boutin S, Wauters LA, McAdam AG, Humphries MM, Tosi G, Dhondt AA (2006) Anticipatory reproduction and population growth in seed predators. Science 314:1928–1930

    Article  CAS  PubMed  Google Scholar 

  • Brown JH, Gillooly JF, Allen AP, Savage VM, West GB (2004) Toward a metabolic theory of ecology. Ecology 85:1771–1789

    Article  Google Scholar 

  • Calenge C (2006) The package adehabitat for the R software: a tool for the analysis of space and habitat use by animals. Ecol Modell 197:516–519

    Article  Google Scholar 

  • Chevallier C, Gauthier G, Lai S, Berteaux D (2020) Pulsed food resources affect reproduction but not adult apparent survival in arctic foxes. Oecologia 193:557–569

    Article  PubMed  Google Scholar 

  • Cody ML (1966) A general theory of clutch size. Evolution 20:174–184

    Article  PubMed  Google Scholar 

  • Dantzer B, Boutin S, Humphries MM, McAdam AG (2012) Behavioral responses of territorial red squirrels to natural and experimental variation in population density. Behav Ecol Sociobiol 66:865–878

    Article  Google Scholar 

  • Dantzer B, McAdam AG, Humphries MM, Lane JE, Boutin S (2020) Decoupling the effects of food and density on life-history plasticity of wild animals using field experiments: insights from the steward who sits in the shadow of its tail, the North American red squirrel. J Anim Ecol 89:2397–2414

    Article  PubMed  Google Scholar 

  • Dantzer B, Newman AEM, Boonstra R, Palme R, Boutin S, Humphries MM, McAdam AG (2013) Density triggers maternal hormones that increase adaptive offspring growth in a wild mammal. Science 340:1215–1217

    Article  CAS  PubMed  Google Scholar 

  • Dawkins R (1982) The Extended Phenotype. WH Freeman, Oxford

  • Dawkins R (1978) Replicator selection and the extended phenotype. Z Tierpsychol 47:61–7

    Article  CAS  PubMed  Google Scholar 

  • Descamps S, Boutin S, Berteaux D, Gaillard JM (2007) Female red squirrels fit Williams’ hypothesis of increasing reproductive effort with increasing age. J Anim Ecol 76:1192–1201

    Article  PubMed  Google Scholar 

  • Descamps S, Boutin S, Berteaux D, Gaillard JM (2008) Age-specific variation in survival, reproductive success and offspring quality in red squirrels: evidence of senescence. Oikos 117:1406–1416

    Article  Google Scholar 

  • Descamps S, Boutin S, McAdam AG, Berteaux D, Gaillard JM (2009) Survival costs of reproduction vary with age in North American red squirrels. Proc R Soc Lond B 276:1129–1135

    Google Scholar 

  • Donald JL, Boutin S (2011) Intraspecific cache pilferage by larder-hoarding red squirrels (Tamiasciurus hudsonicus). J Mammal 92:1013–1020

    Article  Google Scholar 

  • Drent RH, Daan S (1980) The prudent parent: Energetic adjustments in avian breeding. Ardea 68:225–252

    Google Scholar 

  • Festa-Bianchet M, Gaillard JM, Jorgenson JT (1998) Mass- and density-dependent reproductive success and reproductive costs in a capital breeder. Am Nat 152:367–379

    Article  CAS  PubMed  Google Scholar 

  • Festa-Bianchet M, King WJ (2007) Age-related reproductive effort in bighorn sheep ewes. Écoscience 14:318–322

    Article  Google Scholar 

  • Fisher DN, Haines JA, Boutin S, Dantzer B, Lane JE, Coltman DW, McAdam AG (2019) Indirect effects on fitness between individuals that have never met via an extended phenotype. Ecol Lett 22:697–706

    Article  PubMed  Google Scholar 

  • Fletcher QE, Boutin S, Lane JE, LaMontagne JM, McAdam AG, Krebs CJ, Humphries MM (2010) The functional response of a hoarding seed predator to mast seeding. Ecology 91:2673–2683

    Article  PubMed  Google Scholar 

  • Fletcher QE, Landry-Cuerrier M, Boutin S, McAdam AG, Speakman JR, Humphries MM (2013) Reproductive timing and reliance on hoarded capital resources by lactating red squirrels. Oecologia 173:1203–1215

    Article  PubMed  Google Scholar 

  • Fletcher QE, Speakman JR, Boutin S, McAdam AG, Woods SB, Humphries MM (2012) Seasonal stage differences overwhelm environmental and individual factors as determinants of energy expenditure in free-ranging red squirrels. Funct Ecol 26:677–687

    Article  Google Scholar 

  • Gaillard JM, Festa-Bianchet N, Delorme D, Jorgenson J (2000) Body mass and individual fitness in female ungulates: bigger is not always better. Proc R Soc Lond B 267:471–477

    Article  CAS  Google Scholar 

  • Gaillard JM, Garratt M, Lemaitre JF (2017) Senescence in mammalian life history traits. In: Shefferson RP, Jones OR, Salguero-Gomez R (eds) The Evolution of Senescence in the Tree of Life. Cambridge University Press, Cambridge, pp 126–155

    Chapter  Google Scholar 

  • Gunn MR, Dawson DA, Leviston A, Hartnup K, Davis CS, Strobeck C, Slate J, Coltman DW (2005) Isolation of 18 polymorphic microsatellite loci from the North American red squirrel, Tamiasciurus hudsonicus (Sciuridae, Rodentia), and their cross-utility in other species. Mol Ecol 5:650–653

    Article  CAS  Google Scholar 

  • Haines JA (2017) Resources and reproductive trade-offs affect fitness, life history traits, and sexual selection in red squirrels. Doctoral dissertation, University of Alberta, Edmonton

  • Haines JA, Nason SE, Skurdal AMM et al (2020) Sex- and context-specific associations between personality and a measure of fitness but no link with life history traits. Anim Behav 167:23–39

    Article  Google Scholar 

  • Hall JM, Mitchell TS, Thawley CJ, Stroud JT, Warner DA (2020) Adaptive seasonal shift towards investment in fewer, larger offspring: evidence from field and laboratory studies. J Anim Ecol 89:1242–1253

    Article  PubMed  Google Scholar 

  • Hau M, Dominoni D, Casagrande S, Buck CL, Wagner G, Hazlerigg D, Grieves T, Hut RA (2017) Timing as a sexually selected trait: the right mate at the right moment. Phil Trans R Soc B 372:20160249

    Article  PubMed  PubMed Central  Google Scholar 

  • Hendrix JG, Fisher DN, Martinig AR, Boutin S, Dantzer B, Lane JE, McAdam AG (2020) Territory acquisition mediates the influence of predators and climate on juvenile red squirrel survival. J Anim Ecol 89:1408–1418

    Article  PubMed  Google Scholar 

  • Hill GE (1990) Female house finches prefer colourful males: sexual selection for a condition-dependent trait. Anim Behav 40:563–572

    Article  Google Scholar 

  • Hindell MA, Bradshaw CJA, Brook BW, Fordham DA, Kerry K, Hull C, McMahon CR (2012) Long-term breeding phenology shift in royal penguins. Ecol Evol 2:1563–1571

    Article  PubMed  PubMed Central  Google Scholar 

  • Hodgdon HE, Larson JS (1973) Some sexual differences in behaviour within a colony of marked beavers (Castor canadensis). Anim Behav 21:147–152

    Article  Google Scholar 

  • Holzer B, Jacot A, Brinkhof MWG (2003) Condition-dependent signaling affects male sexual attractiveness in field crickets, Gryllus campestris. Behav Ecol 14:353–359

    Article  Google Scholar 

  • Jenkins SH (2011) Sex differences in repeatability of food-hoarding behaviour of kangaroo rats. Anim Behav 81:1155–1162

    Article  Google Scholar 

  • Kalinowski ST, Taper ML, Marshall TC (2007) Revising how the computer program CERVUS accommodates genotyping error increases success in paternity assignment. Mol Ecol 16:1099–1106

    Article  PubMed  Google Scholar 

  • Kenagy GJ, Sharbaugh SM, Nagy KA (1989) Annual cycle of energy and time expenditure in a golden-mantled ground squirrel population. Oecologia 78:269–282

    Article  CAS  PubMed  Google Scholar 

  • Kenward RE (2001) A Manual for Wildlife Radio-tagging. Academic Press, London

    Google Scholar 

  • Kerr TD, Boutin S, LaMontagne JM, McAdam AG, Humphries MM (2007) Persistent maternal effects on juvenile survival in North American red squirrels. Biol Lett 3:289–291

    Article  PubMed  PubMed Central  Google Scholar 

  • Key C, Ross C (1999) Sex differences in energy expenditure in non-human primates. Proc R Soc Lond B 266:2479–2485

    Article  CAS  Google Scholar 

  • Körner M, Vogelweith F, Foitzik S, Meunier J (2017) Condition-dependent trade-off between weapon size and immunity in males of the European earwig. Sci Rep 7:7988

    Article  PubMed  PubMed Central  Google Scholar 

  • Krebs CJ, Boutin S, Boonstra R (2001) Ecosystem Dynamics of the Boreal Forest: the Kluane Project. Oxford University Press, New York

    Google Scholar 

  • Kumari PV, Khan JA (1979) Food hoarding by Indian gerbil, Tatera indica indica (Hardwicke). Proc Indian Acad Sci Anim Sci 88:131–135

  • Kuznetsova A, Brockhoff PB, Christensen RHB (2017) lmerTest package: tests in linear mixed effect models. J Stat Softw 82:1–26

    Article  Google Scholar 

  • Yosef R, Pinshow B (1989) Cache size in shrikes influences female mate choice and reproductive success. Auk 106:418–421

    Google Scholar 

  • LaMontagne JM, Boutin S (2007) Local-scale synchrony and variability in mast seed production patterns of Picea glauca. J Ecol 95:991–1000

    Article  Google Scholar 

  • LaMontagne JM, Williams CT, Donald JL, HM M, McAdam AG, Stan B (2013) Linking intraspecific variation in territory size, cone supply, and survival of North American red squirrels. J Mamm 94:1048–1058

    Article  Google Scholar 

  • Lane JE, Boutin S, Gunn MR, Coltman DW (2009) Sexually selected behaviour: Red squirrel males search for reproductive success. J Anim Ecol 78:296–304

    Article  PubMed  Google Scholar 

  • Lane JE, Boutin S, Gunn MR, Slate J, Coltman DW (2007) Genetic relatedness of mates does Not predict patterns of parentage in North American red squirrels. Anim Behav 74:611–619

  • Lane JE, Boutin S, Gunn MR, Slate J, Coltman DW (2008) Female multiple mating and paternity in free-ranging North American red squirrels. Anim Behav 75:1927–1937

    Article  Google Scholar 

  • Lane JE, Boutin S, Speakman JR, Humphries MM (2010) Energetic costs of male reproduction in a scramble competition mating system. J Anim Ecol 79:27–34

    Article  PubMed  Google Scholar 

  • Lane JE, McAdam AG, Mcfarlane SE, Williams CT, Humphries MM, Coltman DW, Gorrell JC, Boutin S (2018) Phenological shifts in North American red squirrels: disentangling the roles of phenotypic plasticity and microevolution. J Evol Biol 31:810–821

    Article  PubMed  Google Scholar 

  • Larivée ML, Boutin S, Speakman JR, McAdam AG, Humphries MM (2010) Associations between over-winter survival and resting metabolic rate in juvenile North American red squirrels. Funct Ecol 24:597–607

    Article  Google Scholar 

  • Larsen KW, Becker CD, Boutin S, Blower M (1997) Effects of hoard manipulations on life history and reproductive success of female red squirrels (Tamiasciurus hudsonicus). J Mammal 78:192–203

    Article  Google Scholar 

  • Larsen KW, Boutin S (1994) Movements, survival, and settlement of red squirrel (Tamiasciurus hudsonicus) offspring. Ecology 75:214–223

    Article  Google Scholar 

  • Larue B, Pelletier F, Festa-Bianchet M (2022) A multivariate perspective of resource acquisition behaviors in bighorn sheep. Anim Behav 184:81–87

    Article  Google Scholar 

  • Laskowski KL, Moiron M, Niemelä P (2021) Integrating behavior in life-history theory: allocation versus acquisition? Trends Ecol Evol 36:132–138

    Article  PubMed  Google Scholar 

  • Lemaitre JF, Gaillard JM (2017) Reproductive senescence: new perspectives in the wild. Biol Rev 92:2182–2199

    Article  PubMed  Google Scholar 

  • Maklakov AA, Simpson SJ, Zajitschek F, Hall MD, Dessmann J, Clissold F, Raubenheimer D, Bonduriansky R, Brooks RC (2008) Sex-specific fitness effects of nutrient intake on reproduction and lifespan. Curr Biol 18:1062–1066

    Article  CAS  PubMed  Google Scholar 

  • Markman S (2014) Parental self-feeding effects on parental care levels and time allocation in Palestine sunbirds. PLoS ONE 9:e113890

    Article  PubMed  PubMed Central  Google Scholar 

  • Marshall TC, Slate J, Kruuk LEB, Pemberton JM (1998) Statistical confidence for likelihood-based paternity inference in natural populations. Mol Ecol 7:639–655

    Article  CAS  PubMed  Google Scholar 

  • Martinig AR, McAdam AG, Dantzer B, Lane JE, Coltman DW, Boutin S (2020) The new kid on the block: immigrant males win big whereas females pay fitness costs after dispersal. Ecol Lett 23:430–438

    Article  PubMed  Google Scholar 

  • McAdam AG, Boutin S (2003) Variation in viability selection among cohorts of juvenile red squirrels (Tamiasciurus hudsonicus). Evolution 57:1689–1697

    Article  PubMed  Google Scholar 

  • McAdam AG, Boutin S (2003) Effects of food abundance on genetic and maternal variation in the growth rate of juvenile red squirrels. J Evol Biol 16:1249–1256

    Article  CAS  PubMed  Google Scholar 

  • McAdam AG, Boutin S, Dantzer B, Lane JE (2019) Seed masting causes fluctuations in optimum litter size and lag load in a seed predator. Am Nat 194:574–589

    Article  PubMed  Google Scholar 

  • McAdam AG, Boutin S, Réale D, Berteaux D (2002) Maternal effects and the potential for evolution in a natural population of animals. Evolution 56:846–851

    Article  PubMed  Google Scholar 

  • McAdam AG, Boutin S, Sykes AK, Humphries MM (2007) Life histories of female red squirrels and their contributions to population growth and lifetime fitness. Ecoscience 14:362

    Article  Google Scholar 

  • McLean IG, Towns AJ (1981) Differences in weight changes and the annual cycle of male and female Arctic ground squirrels. Arctic 34:249–254

    Article  Google Scholar 

  • Milner JM, van Beest FM, Solberg EJ, Storaas T (2013) Reproductive success and failure: the role of winter body mass in reproductive allocation in Norwegian moose. Oecologia 172:995–1005

    Article  PubMed  Google Scholar 

  • Monteith KL, Schmitz LE, Jenks JA, Delger JA, Bowyer RT (2009) Growth of male white-tailed deer: consequences of maternal effects. J Mammal 90:651–660

    Article  Google Scholar 

  • Mousseau TA, Fox CW (1998) The adaptive significance of maternal effects. Trends Ecol Evol 13:403–407

    Article  CAS  PubMed  Google Scholar 

  • Naya DE, Ebensperger LA, Sabat P, Bozinovic F (2008) Digestive and metabolic flexibility allows female degus to cope with lactation costs. Physiol Biochem Zool 81:186–194

    Article  PubMed  Google Scholar 

  • Nishida Y, Takagi M (2019) Male bull-headed shrikes use food caches to improve their condition-dependent song performance and pairing success. Anim Behav 152:29–37

    Article  Google Scholar 

  • Oftedal OT (1985) Pregnancy and lactation. In: Hudson RJ, White RG (eds) Bioenergetics of wild herbivores. CRC Press, Boca Raton, pp 215–238

    Google Scholar 

  • Podofillini S, Cecere JG, Griggio M, Corti M, De Capua EL, Parolini M, Saino N, Serra L, Rubolini D (2019) Benefits of extra food to reproduction depend on maternal condition. Oikos 128:943–959

    Article  Google Scholar 

  • Post E, Forchhammer MC (2008) Climate change reduces reproductive success of an Arctic herbivore through trophic mismatch. Proc R Soc Lond B 363:2369–2375

    Google Scholar 

  • Price K, Boutin S (1993) Territorial bequeathal by red squirrel mothers. Behav Ecol 4:144–150

    Article  Google Scholar 

  • R Core Team (2016) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. http://www.R-project.org

  • Réale D, Berteaux D, McAdam AG, Boutin S (2003) Lifetime selection on heritable life-history traits in a natural population of red squirrels. Evolution 57:2416–2423

    Article  PubMed  Google Scholar 

  • Reddiex AJ, Gosden TP, Bonduriansky R, Chenoweth SF (2013) Sex-specific fitness consequences of nutrient intake and the evolvability of diet preferences. Am Nat 182:91–102

    Article  PubMed  Google Scholar 

  • Reznick D, Callahan H, Llauredo R (1996) Maternal effects on offspring quality in poeciliid fishes. Am Nat 36:147–156

    Google Scholar 

  • Ridgway MS, Shuter BJ (1994) The effects of supplemental food on reproduction in parental male smallmouth bass. Environ Biol Fish 39:201–207

    Article  Google Scholar 

  • Roff DA (1992) The evolution of life histories: theory and analysis. Chapman and Hall, New York

    Google Scholar 

  • Salomon M, Mayntz D, Toft S, Lubin Y (2011) Maternal nutrition affects offspring performance via maternal care in a subsocial spider. Behav Ecol Sociobiol 65:1191–1202

    Article  Google Scholar 

  • Schroeder J, Piersma T, Groen NM, Hooijmeijer JCEW, Kentie R, Lourenco PM, Schekkerman H, Both C (2012) Reproductive timing and investment in relation to spring warming and advancing agricultural schedules. J Ornithol 153:327–336

    Article  Google Scholar 

  • Smith MC (1968) Red squirrel responses to spruce cone failure in Interior Alaska. J Wildlife Manage 32:305–317

    Article  Google Scholar 

  • Snijders TAB, Bosker RJ (1999) Multilevel analysis: an introduction to basic and advanced multilevel modeling. Sage, London

    Google Scholar 

  • Stearns S (1992) The Evolution of Life Histories. Oxford University Press, Oxford

    Google Scholar 

  • Stuart-Smith AK, Boutin S (1994) Costs of escalated territorial defence in red squirrels. Can J Zool 6:1162–1167

    Article  Google Scholar 

  • Vander Wall SB (1990) Food hoarding in animals. University of Chicago Press, Chicago

    Google Scholar 

  • Warner DA, Lovern MB (2014) The maternal environment affects offspring viability via an indirect effect of yolk investment on offspring size. Physiol Biochem Zool 87:276–287

    Article  PubMed  Google Scholar 

  • Westrick SE, Taylor RW, Boutin S, Lane JE, McAdam AG, Dantzer B (2020) Attentive red squirrel mothers have faster growing pups and higher lifetime reproductive success. Behav Ecol Sociobiol 74:72

    Article  Google Scholar 

  • Williams CT, Lane JE, Humphries MM, McAdam AG, Boutin S (2014) Reproductive phenology of a food-hoarding mast-seed consumer: Resource- and density-dependent benefits of early breeding in red squirrels. Oecologia 174:777–788

    Article  PubMed  Google Scholar 

  • Woodroffe R (1995) Body condition affects implantation date in the European badger, Meles meles. J Zool 236:183–188

    Article  Google Scholar 

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Acknowledgements

We thank Agnes MacDonald and her family for long-term access to her trapline, and the Champagne and Aishihik First Nations for allowing us to conduct our work within their traditional territory. We thank the hundreds of field assistants who have helped to collect the data over the decades, Ainsley Sykes for data and project management and Matt Strimas-Mackey for assistance with database management and coding. We also thank two anonymous reviewers for comments that significantly improved the manuscript. This is publication #121 in the Kluane Red Squirrel Project.

Funding

Data collection was supported by grants provided to SB, AGM, and DWC from the Natural Sciences and Engineering Research Council of Canada, to AGM from the National Science Foundation, and to AGM from the Ontario Ministry of Research and Innovation. JAH was supported by an NSERC Doctoral Postgraduate Scholarship, University of Alberta Canadian Circumpolar Institute Circumpolar/Boreal Alberta Research Funds, Aboriginal Affairs and Northern Development Canada Northern Scientific Training Program Grants, and University of Alberta Faculty of Graduate Studies and Research scholarships.

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Author notes

  1. David W. Coltman

    Present address: Department of Biology, Western University, London, ON, Canada

  2. Jessica A. Haines and David M. Delaney contributed equally to this work.

Authors and Affiliations

  1. Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada

    Jessica A. Haines, David W. Coltman & Stan Boutin

  2. Department of Biological Sciences, MacEwan University, Edmonton, AB, Canada

    Jessica A. Haines

  3. Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA

    David M. Delaney & Andrew G. McAdam

  4. Department of Biology, University of Saskatchewan, Saskatoon, SK, Canada

    Andrea E. Wishart & Jeffrey E. Lane

  5. Department of Integrative Biology, University of Guelph, Guelph, ON, Canada

    Andrew G. McAdam

  6. Department of Psychology, University of Michigan, Ann Arbor, MI, USA

    Ben Dantzer

  7. Department of Ecology & Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA

    Ben Dantzer

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Correspondence to Andrea E. Wishart.

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Approval to conduct this study was granted by the University of Alberta Animal Care and Use Committee for Biosciences in accordance with the Canadian Council on Animal Care Guidelines and Policies. All applicable international, national, and/or institutional guidelines for the use of animals were followed. Fieldwork was permitted under Yukon Territorial Government Wildlife Research Permits and Scientists & Explorer’s Permits.

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Haines, J.A., Delaney, D.M., Wishart, A.E. et al. Sex-specific effects of capital resources on reproductive timing and success in red squirrels. Behav Ecol Sociobiol 76, 142 (2022). https://doi.org/10.1007/s00265-022-03245-y

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