Sociability in greylag geese : the effects of hand-rearing vs. wild-rearing on animal personality

Abstract

iii, 22 p.This study investigates the influence of hand-rearing on animal personality, specifically focusing on sociability. A free-flying flock of 108 greylag geese (Anser anser) at the Konrad Lorenz Research Center in Austria was used. This research compared the sociability of human-reared individuals against the sociability of wild-reared individuals. Sociability scores were determined through scan sampling of resting geese, defining the score as the number of conspecifics within a 2-meter radius of a focal goose. Initial t-test analyses indicated that hand-reared geese were significantly more social than wild-reared geese. However, more robust Generalized Linear Mixed Models (GLMMs), which accounted for individual identity, birth year and rearing type, revealed a more complex relationship: rearing method itself had no significant independent effect on sociability. Instead, birth year emerged as a primary driver, with geese becoming significantly less sociable as they aged. Crucially, the study found a significant interaction between birth year and rearing type, demonstrating that while both groups become less social over time, hand-reared geese lose sociability at a faster rate than wild-reared geese