UCLA

A variety of intrinsic and extrinsic factors shape an animal’s antipredator behavior. Flight Initiation Distance (FID) is a common measurement for evaluating antipredator behavior and is used to assess an individual’s shyness or boldness. Numerous Flight Initiation Distance studies, in a variety of taxa, have shown that FID is an economic decision that is sensitive to both the costs and benefits of flight. While there is some evidence that individuals may have repeatable FIDs, and there are several genes associated with FID (DRD4 and SERT), few studies have quantified the heritability of FID. Knowledge of heritability permits us to understand the evolutionary potential of a trait within a population, and heritable variation is yet another mechanism that enables animals to respond to a dynamically changing world. Here we conduct a variance decomposition analysis using the quantitative genetic mixed model (i.e., the “animal model”) to identify the degree to which genetic and non-genetic factors explain variation in FID within a population of wild yellow-bellied marmots (Marmota flaviventer). Within our 18-year dataset of individually marked individuals, we found significant heritable variation for FID that we estimated at 0.16. These results demonstrate that genetics, in addition to environmental factors, influence an animal’s fear response. Understanding evolvability and plasticity of FID could have important implications for conservation.