The claim to fame of the Grey-Crowned Crane is that it is one of the only cranes 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 or its smaller and more aquatic relative, the limpkin" (Matthiessen 2003).
The Grey-Crowned Crane is globally restricted to Africa where the South African population, and the populations of Zimbabwe, Botswana and Namibia, make up the smaller population of the two subspecies. They require a mixture of wetlands and grasslands for summer breeding and foraging although they are increasingly found in man-modified habitats (agricultural lands). The overriding conservation challenge is therefore to develop sustainable management alternatives for their co-existence with agriculture on privately-owned land. This species faces widespread degradation of its breeding and feeding habitats and is still persecuted by landowners in some areas – who think that the bird is eating crops whereas they are more likely to be eating insects on those crops (McCann 2002). Over the past two decades, Grey-Crowned Crane numbers have declined by about 15% due to increased human-induced impacts.
Grey-Crowned Cranes nest within or on the edges of wetlands where they build a strong nest from the tall wetland plants, cleverly concealed from predators and the prying eyes of people. They like to forage in open grasslands adjacent to wetlands where they eat grass seeds, insects and other invertebrates – they have also taken to agricultural lands including pastures, fallow fields, maize crops, cabbages and harvested croplands. This generalist feeding strategy has allowed this species to adapt to human settlement better than the Wattled or Blue Cranes and it is regularly now found in this transformed habitat. Unlike other crane species, this crane roosts in trees – its voice has considerable harmonic development and can be heard for miles – cranes use many different calls to communicate and can be very boisterous upon returning to the roost (Cooley 1993). Non-migratory, they do move around locally and in the winter months, large flocks of non-breeding Grey-Crowned Cranes can be found dancing and calling before the onset of the summer breeding period. Intensification of agriculture, tourism development and industrialisation are threatening grasslands at a terrifying rate and indigenous species like cranes are being forced into smaller territories. Wetlands also are alarmingly threatened by human impacts and forcing the Grey-Crowned Crane into populated areas where danger lurks.
Grey-Crowned Cranes also reach maturity at the age of three to four years and once they have found a mate, they usually lay 2 – 3 large smooth eggs in a wetland nest surrounded by tall reeds, secluded from predators. These spring and summer breeders incubate their eggs for about 30 days and take their chicks out onto a nursery area of flattened reeds before they venture into the real world to forage. Chicks fledge at 3 – 4 months and leave their parents when almost a year old to join one of the non-breeding flocks where they look for a mate.