Dispersal is an important individual decision which may influence individual fitness as well as population viability.The social cohesion hypothesis posits more social individuals remain at home,which is supported by p...Dispersal is an important individual decision which may influence individual fitness as well as population viability.The social cohesion hypothesis posits more social individuals remain at home,which is supported by prior work across taxa.However,how the sociality and connectivity of the group an individual resides in—their group social structure—relates to dispersal decisions has not been explored.We extend the social cohesion hypothesis to predict individuals residing in more social groups would remain at home,and we quantified the affiliative and agonistic social network structure of female yellow-bellied marmots(Marmota flaviventer),a facultatively social ground-dwelling squirrel,where about half of all females disperse.Using mixed-effects models,we found no support for the hypothesis that affiliative group structure explained any variation in a marmot’s decision to disperse.We did find marmots in groups with less agonistic centralization(around one or few individuals)were less likely to disperse.The former finding may result from limited ability to perceive group structure whereas the latter may reflect individuals in less agonistically centralized groups are less likely to be reproductively suppressed.These results suggest individual dispersal decisions are more impacted by individual sociality and not that of their social group.Thus,the social cohesion hypothesis may not scale to the level of the group.Further work is required to determine whether dispersal decisions in obligately social species are influenced by group social structure.展开更多
基金supported by the Hamilton College Jeffery Fund Science Internship and the Rocky Mountain Biological Laboratorysupported by the University of California Los Angeles,American Society of Mammalogists,the Animal Behavior Society,and Rocky Mountain Biological Laboratory+1 种基金supported by the National Geographic Society,the University of California Los Angeles(Faculty Senate and Division of Life Sciences),an RMBL research fellowshipU.S.National Science Foundation(NSF IDBR-0754247 and DEB-1119660 and 1557130 to D.T.B.,as well as DBI 0242960,07211346,1226713,and 1755522 to RMBL).
文摘Dispersal is an important individual decision which may influence individual fitness as well as population viability.The social cohesion hypothesis posits more social individuals remain at home,which is supported by prior work across taxa.However,how the sociality and connectivity of the group an individual resides in—their group social structure—relates to dispersal decisions has not been explored.We extend the social cohesion hypothesis to predict individuals residing in more social groups would remain at home,and we quantified the affiliative and agonistic social network structure of female yellow-bellied marmots(Marmota flaviventer),a facultatively social ground-dwelling squirrel,where about half of all females disperse.Using mixed-effects models,we found no support for the hypothesis that affiliative group structure explained any variation in a marmot’s decision to disperse.We did find marmots in groups with less agonistic centralization(around one or few individuals)were less likely to disperse.The former finding may result from limited ability to perceive group structure whereas the latter may reflect individuals in less agonistically centralized groups are less likely to be reproductively suppressed.These results suggest individual dispersal decisions are more impacted by individual sociality and not that of their social group.Thus,the social cohesion hypothesis may not scale to the level of the group.Further work is required to determine whether dispersal decisions in obligately social species are influenced by group social structure.
