Meeting Abstract

P2-159    Do squirrel moms have longer tails? Tail lengths in male versus female fox squirrels (Sciurus niger) Nichols, H*; Smith, S K; Eddington, V; Calistri-Yeh, A; Kloepper, L N; Young, VKH; Saint Mary's College; Saint Mary's College; Saint Mary's College; Northwestern University; Saint Mary's College; Saint Mary's College hnichols01@saintmarys.edu

Reproduction is a costly activity, and has been shown to result in reduced locomotor performance in female animals. Although such costs can be observed in females in a variety of habitats (e.g., aquatic, terrestrial, arboreal), arboreal environments present unique challenges to locomotion. Many arboreal mammals rely on long tails to aid in balance while maneuvering complex and dynamic habitats. However, pregnancy can alter body mass and/or shape, leading to shifts in center of mass. Such changes in center of mass may increase an individual’s risk of losing balance and falling. Longer tails could offset the effects of pregnancy by providing a more effective counter-balance mechanism when females are heavier and less stable. To test this hypothesis, we collected morphological data from 57 fox squirrels (Sciurus niger) on the Saint Mary’s College campus (Notre Dame, IN) in 2019 and 2021. Relative tail length to body length (RTL) was compared between males and females. Our results showed a significant difference in RTL between females and males; female RTL was 7.7% longer than male RTL. The results of our study indicate a morphological response to selection pressures associated with pregnancy in fox squirrels.