Individual asymmetry as a predictor of fitness in the bat Carollia perspicillata

The measurement of fitness in wild populations is a challenging task, and a number of proxies have been proposed with different degrees of success. Developmental instability/stability (DI) is an organismal property associated with variance in bilateral asymmetry (fluctuating asymmetry – FA), and a correlated effect on fitness. This study provides evidence to corroborate the hypothesis that asymmetry partly reflects DI and is correlated with a reduction in fitness measured by survival and reproduction in bats. We studied two Colonies of the bat Carollia perspicillata in Southeastern Brazil over five years, marking and recapturing individuals. Gaussian mixture models for signed forearm asymmetry distribution indicated that ~20% of asymmetry variation was due to DI heterogeneity among individuals. Forearm Asymmetry (ForA), Body Condition (Scaled Mass Index – SMI) and Forearm Length (ForL) were used as predictors of survival probability in Cormack-Jolly-Seber models. Asymmetry was negativel...