Grey crowned crane, Balearica regulorum
The Grey Crowned Crane is the most abundant of the resident African cranes. B. r. regulorum
(the South African Crowned Crane) is found in Zimbabwe and South Africa and is classified as endangered. Over the past two decades, Grey Crowned Crane numbers have declined by about 15% due to increased human-induced impacts, only some 4 000 Grey-Crowned Cranes are left in South Africa today.
The Grey Crowned Crane is about 1 m tall and weighs 3.5 kg. The sexes are similar, although males tend to be slightly larger. Young birds are greyer than adults, with a feathered buff face.
This crane is one of only two crane species to roost in trees and the most primitive crane – it is thought to resemble the many pre-Pliocene fossils from North America and central Asia. The first crane-like birds, which appeared in the age of dinosaurs, were somewhat similar in body dimensions to a modern crowned crane.
Distribution and habitat:
Grey Crowned Cranes are non-migratory, but undertake local and seasonal movements in response to changing moisture levels and food availability. They use mixed wetland-grassland habitats for nesting and foraging. The crane is restricted to the moist eastern, higher rainfall areas of the country, from the Eastern Cape Province, throughout the western parts of KwaZulu-Natal and north-eastern Free State, into the south-eastern regions of Mpumalanga. This species is particularly abundant in higher altitudes such as in the north Eastern Cape and southern KwaZulu-Natal.
The Grey Crowned Crane has a breeding display involving dancing, bowing, and jumping. It has a booming call and makes a honking sound quite different from the trumpeting of other crane species.
Their preferred foraging habitat consists of expanses of short- to medium-height open grasslands adjacent to wetlands. There they feed on the tips of grasses, seeds, insects and other invertebrates, and small vertebrates. They also forage in croplands for groundnuts, soybeans, maize, millet, and other items
Breeding and nesting:
They typically nest within or on the edges of wetlands in areas where wetland vegetation is of sufficient height to conceal the cranes on their nests. While rearing chicks, adult birds will sometimes hide their young in the wetland in the evening, and then fly to roost in trees.
Grey Crowned Cranes are sexually mature at three (rarely two) years. The species lays a clutch of 2-5 eggs and has the largest average clutch size (2.5+) of any crane. Nests consist of uprooted grasses and sedges piled and flattened into a circular platform. The incubation period is 28-31 days. Incubation is performed by both sexes. The fledging period is variable, generally between 56-100 days.