diagnostics
90-130 cm, 3.3-4.4 kg. An unmistakeable, large, black bird with white primaries. Adults have bare, red, inflatable skin on the throat and face, with females showing a blue patch across the throat at the base of the lower mandible. Males also have a larger bill and casque than females at all ages. Juveniles are sooty black, their white primaries flecked with black. Dull grey eyes change to bright yellow as birds mature. Immatures have dull grey facial skin, which changes to creamy yellow, orange and red as they mature over 4-6 years. The legs and bill are black, but immatures have paler grey areas on the proximal sides of their mandibles (Kemp 1995).
trophic
The Southern Ground-Hornbill is a monogamous, cooperative breeder with a single, dominant breeding pair within a group supported by helpers (Kemp 2005). Natural cavities in live or dead trees are most commonly used, but also cliffs and, rarely, self-excavated hollows in earth banks or old stick nests of other species. Artificial cavities are readily accepted. Chicks hatch asynchronously with the second hatched chick normally falling victim to passive siblicide, being unable to compete with its larger sibling (Kemp 2005), or to parental cannibalism. 49% of breeding attempts fledge one chick and 31% of fledged chicks survive to maturity (Kemp 2005). Mean recruitment is extremely low, with groups fledging an average of only one chick every 9.3 years (n=14 groups, 20 breeding seasons; Kemp 1988), making the species exceptionally vulnerable to any type of increased mortality. A generation length of 31.3 years is estimated based on mean age at first breeding, maximum longevity in the wild and mean annual adult survival (BirdLife International 2014). The species has a catholic diet, feeding on a range of invertebrates and small amphibians, reptiles, mammals and birds.
