Tail length in male versus female fox squirrels (Sciurus niger)

BackgroundArboreal mammals rely on their tails to aid in balance while maneuvering complex habitats. Females experience additional challenges to locomotion due to reproductive demands including altered body mass and/or body shape, which leads to shifts in center of mass. Without compensation, this may increase the risk of losing balance and falling out of trees. We tested the hypothesis that female squirrels have longer tails than males to offset shifts in center of mass that may result from pregnancy. ResultsMorphological data were collected from 57 fox squirrels (Sciurus niger) in northern Indiana in summer 2019 and 2021. Although our initial t-test analysis of relative tail length (RTL) showed that female squirrels had longer tails than males (p = 0.02), a subsequent ANCOVA that controlled for effect of body length indicated no significant effect of sex on tail length (p = 0.42). ConclusionsThe results of this study demonstrate the potential impacts of different analysis methods on overall understanding of organismal functional morphology and are an important addition to the literature on tail form and function, which remains poorly understood compared to other appendages.