Endocrine correlates of gender and throat coloration in the southern ground-hornbill (Bucorvus leadbeateri).

The southern ground-hornbill (SGH) is a cooperatively breeding bird endemic to eastern and southern Africa, but is endangered in its southern distributional range. The national conservation restoration program harvests redundant chicks for captive breeding and reintroduction; with sexing and social grouping of the species evaluated by throat-skin coloration, with adult males displaying a completely red color compared to dark blue within the red observed in adult females. However, recent findings indicate that dominant and subordinate adult males exhibit patches of blue throat-skin.