Ecology and behaviour of Palm-nut Vultures Gypohierax angolensis in the Bijagós Archipelago, Guinea-Bissau

A recent study in the Bijagós Archipelago, Guinea-Bissau, reveals that Palm-nut Vultures (Gypohierax angolensis) rely heavily on oil palm fruits for sustenance, despite preferring fish in cafeteria trials. Using stable isotope analysis and Bayesian mixing models, researchers estimated that nearly 50% of the vultures' assimilated diet consists of these fruits, followed by fish, crabs, and Green Turtle hatchlings or eggs. The study also found a population density of 21–30 birds per km² in João Vieira and Poilão Marine National Park, with egg-laying occurring from November to May and an annual fledgling success rate of at least 54%. Additionally, the vultures were observed to molt all flight feathers annually between January and November. This research sheds light on the species' ecological and behavioral adaptations, contributing crucial data for conservation efforts.

Carneiro, C., Henriques, M., Barbosa, C., Tchantchalam, Q., Regalla, A., Patrício, A. R., & Catry, P. (2017). Ecology and behaviour of Palm-nut Vultures Gypohierax angolensis in the Bijagós Archipelago, Guinea-Bissau. Ostrich, 88(2), 113–121. https://doi.org/10.2989/00306525.2017.1291540