Kin effects on energy allocation in group-living ground squirrels.
The social environment has potent effects on individual phenotype and fitness in group-living species. We asked whether the presence of kin might act on energy allocation, a central aspect of life-history variation. Using a 22-year data set on reproductive and somatic allocations in Columbian ground squirrels (Urocitellus columbianus), we tested the effects of co-breeding and non-breeding kin on the fitness and energy allocation balance between reproduction and personal body condition of individual females. Greater numbers of co-breeding kin had a positive effect on the number of offspring weaned, through the mechanism of altering energy allocation patterns. On average, females with higher numbers of co-breeding kin did not increase energy income but biased energy allocation towards reproduction. Co-breeding female kin ground squirrels maintain close nest burrows, likely providing a social buffer against territorial invasions from non-kin ground squirrels. Lower aggressiveness, lower risks of infanticide from female kin and greater protection of territorial boundaries may allow individual females to derive net fitness benefits via their energy allocation strategies. We demonstrated the importance of kin effects on a fundamental life-history trade-off.
Institut Pluridisciplinaire Hubert Curien (IPHC), Département Ecologie Physiologie et Ethologie (DEPE), Université de Strasbourg, 23 rue Becquerel, Strasbourg, 67087, France.|CNRS, UMR7178, Strasbourg, 67087, France.
Vincent A
VA
Viblanc
UMR MARBEC, IFREMER (Institut Français de Recherche pour l'Exploitation de la Mer), Sète, France.
Claire
C
Saraux
Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada.
Jan O
JO
Murie
Department of Biological Sciences, Auburn University, 311 Funchess Hall, Auburn, AL, 36849, USA.
F Stephen
FS
Dobson
D000416:Alberta; D000818:Animals; D004734:Energy Metabolism; D005260:Female; D056084:Genetic Fitness; D012098:Reproduction; D012589:Sciuridae / Q000235:genetics / Q000502:physiology*; D013731:Territoriality
energy; kin selection; life-history trade-offs; matriline; philopatry; reproductive allocation; somatic allocation