Geronticus calvus
KINGDOM: Animalia (Animals)
PHYLUM: Chordata (Possessing a notochord)
CLASS: Aves (Birds)
ORDER: Ciconiiformes (Stork family)
FAMILY: Threskiornithidae (Large Wading Birds)
SUB-FAMILY: Threskiornithinae (Ibises)
GENUS: Geronticus (Bald Ibises)
SPECIES: Geronticus calvus (Southern Bald Ibis)
Distribution
The species has a very restricted home range, limited to the southern tips of South Africa with its main range lying in the north-eastern Free State, Mpumalanga and the KwaZulu-Natal Drakensberg.
The Southern bald ibis has a bare head and wrinkled skin on the face and neck. Its plumage is dark green with iridescent streaks of green, violet and bronze. However, as juveniles, the plumage is predominantly a dull grey colour.
The southern bald ibis can be found in semi-desert areas and mountainous regions that have short grasses in grassland and high altitudes.
This species is insectivorous and feeds predominantly on insects and other small terrestrial invertebrates. The main component of its diet is the caterpillar of the maize stalk borer (Busseola fusca), as well as caterpillars, grasshoppers, beetles, earthworms, snails and sometimes frogs, small dead mammals and birds.
These ibises feed and roost in large flocks. Their nests are built on flat ground or on cliffs and in trees, where they will roost with up to 50 or more other individuals. It is a gregarious bird that will hunt with up to 100 other birds of its type.
Southern bald ibises are monogamous (having one partner at a time). Their nests are made mostly of sticks and grass. Once the first egg is laid, incubation last from 26 to 32 days. The incubating birds change their position and rotate the egg frequently around for three days before the hatching day. Once hatched, the chicks spend the first 7 to 10 days feeding from their parents via regurgitation. After 35 days, the young leave the nest to wander around and after 40 to 50 days, the chicks are able to fly, but still spend most of their time on the ledges of the cliff or in their nest.
The southern bald ibis is likely to live for between 10 and 15 years in the wild and for up to 30 years in captivity.
The Southern bald ibis has long been hunted by people for their meat and feathers. Human interference with breeding colonies and habitat loss through commercial afforestation, intensive crop farming, open-cast mining, acid rain and dense human settlement are also threatening southern bald ibis colonies. Pesticide contamination is a potential threat as is exploitation for traditional medicinal/ceremonial purposes in Lesotho. The species’ habit of using electricity pylons as roost sites in certain areas results in some mortalities from collisions with power lines
Did you know?
- The bird is teased for being bald headed and wrinkled skin on the face and neck. Hence, it is referred to as an “old man”