Behaviour 2019
Consequences of social structure for mass gain in an alpine hibernator
Conner S. Philson, Sophia Todorov, Daniel T. Blumstein. University of California, Los Angeles, Los Angeles, CA, United States

Work across biological systems has explored the consequences of social interactions for both fitness and social structure. Less work has mapped the relationship between attributes of social structure and individual fitness correlates, which is important to understanding the consequences of social behavior. For hibernating species, such as the yellow-bellied marmot (Marmota flaviventer), gaining adequate mass rapidly leading up torpor is a vital for survival. Therefore, we explored the association between social structure and individual marmot mass gain rates at the Rocky Mountain Biological Laboratory in Colorado. Social networks were constructed from 43,362 behavioral observations of 1,350 individuals in 132 unique social groups from 2002 to 2018. Using linear mixed models, we found that yearlings, more so than adults, residing in more connected and complex social groups tended to gain proportionally less mass. While effect sizes of social structure were small, these results show how the structure and complexity of the social group an individual resides in has modest relationship with a key fitness correlate, depending on an individual’s life history stage.