Individual body mass and sex of a frugivorous bird affect the quality of seed dispersal

Frugivorous animals play crucial roles dispersing seeds away from parental plants and influencing plant recruitment. Most studies focus on comparisons of seed dispersal services provided by distinct species of animals, but neglect how within-species variation may affect dispersal. Individual traits, such as body mass and sex, are related to metabolic rates, gut load capacity, and transit times that potentially influence dispersal quantity and quality. Here, we aim to answer if individual traits (body mass and sex) of Pale-breasted Thrushes (Turdus leucomelas) affect seed dispersal quality by testing the following hypotheses (a) individual traits influence seed retention time and germination, (b) seed retention time affects seed germination and (c) seed passage through the gut enhances germination. We found that females retained seeds in the gut for longer periods than males. Gut-passed and manually depulped seeds had similar germination success. However, heavier birds, irrespective of s...