BREEDING PROGRAMMES - blue crane

Blue Crane : Anthropoides paradisea (Lichtenstein AAH 1799)

Review and perspective

The blue crane is also referred to as the Stanley crane or paradise crane. This species is near endemic to Southern Africa with about 99% of the total population of these birds occurring in South Africa. An isolated population of between 60 and 80 resident birds also occur in the Etosha region of northern Namibia. Breeding pairs have also occasionally been recorded in Botswana and Zimbabwe.

The blue crane was classified as vulnerable by the IUCN in 2003.

The estimated number for this species in the wild varies from about 10 000 to 25 000 mature birds with the most acknowledged figures varying from 21 000 to 23 000.

It could be estimated that there are about 400 individuals in captive environment (in the absence of any concrete data).

Background of the status of blue cranes

Blue, grey crowned and wattled cranes are the only three crane species that occur in South Africa. Although the blue cranes are the most numerous of the three species, their range is largely limited to this country, whereas the grey crowned cranes and wattled cranes are distributed throughout a larger area extending to the southern-central parts of Africa.

Around 1980, there was little concern regarding the conservation status of blue cranes in South Africa. During the late 1980s and early 1990s, however, concern was raised about the decline in numbers of these birds in parts of their original range. The species had by then almost disappeared from the Transkei. Lesotho and Swaziland – while the numbers also declined in the Northern Free State, Kwazulu Natal, The Eastern Cape and the former Transvaal Province – by as much as 80 to 90%!

The decline of the three species of cranes in South Africa led to the establishment of different NGOs in the late 1980s and the first half of the 1990s with objectives to protect these species. These groups are currently co-ordinated by the South African Crane Working Group (SACWG) that was established in 1995 under the auspices of the Endangered Wildlife Trust (EWT).

The SACWG has established that the major reasons for the decline of the blue cranes are unintentional poisoning when birds feed on crop seeds that are treated with insecticides before planting, intentional poisoning, where birds are poisoned because of the habit of flocks of birds to dig up seeds that had been planted, as well as habitat loss due to human population pressure and land use practises. The areas where commercial afforestation replaced grasslands, in particular, contributed to the decline in the blue crane habitat. Large numbers of these birds are also killed by flying into power lines. In localized areas, crane species are also killed as a source of food, while predation of chicks by domestic dogs has led to a decline in the numbers of blue cranes as well.

Rationale for breeding blue cranes in captive environments

Blue cranes are intentionally sought after by zoos and bird parks as well as other similar environmental education establishments. As it is illegal to remove blue cranes from the wild, the demand for blue cranes by accredited captive institutions and zoos has mainly been met by captive bred birds from breeding programmes.

As far as te available stock of blue cranes in captive environments is concerned, most of the birds are held in zoos, bird parks and similar institutions. This stock was also supplemented when landowners, especially in the Western Cape region, collected blue crane chicks that appeared to have been abandoned by the parental birds around newly cultivated lands, and transferred them to different zoos as well as other captive facilities. The intention was that the birds could be used by these institutions for display and possible breeding programmes. This practice came to an end after the establishment of the SACWG. Research then indicated that most of these chicks were not abandoned but that the male and female birds usually reunite with the chicks. The current principle is that only the injured and permanently disabled birds may be used to supplement breeding programmes and educational purposes.

The Conservation Breeding Specialist Group (CBSG) held a series of workshops under the auspices of the IUCN/ SSG to assess the in situ and ex situ status of crane species in order to develop strategies for the preservation of all crane species. This led to a meeting and workshop of the Conservation Assessment and Management Plan (CAMP) in 1992 that made recommendations for the conservation of blue cranes. Amongst others, they advised that a coordinated ex situ breeding programme be properly managed with at least 200 birds of known genetic and diverse origin. They also advised that as these birds are well represented in South Africa, breeding should be concentrated on this country. The rationale being that the genetic diversity of birds available for breeding in the country is adequate to manage sound breeding programmes.

In order to breed successfully, blue cranes need relatively large enclosures with limited disturbance – resembling their natural breeding habitat. This largely limits the breeding of blue cranes to zoos and bird parks with designated breeding programmes and appropriate facilities. Where blue cranes are held in smaller holding areas for the use of public display or educational purposes, they do not breed successfully.

To be able to supply the international demand for blue cranes by accredited zoological institutions, the institutions that breed blue cranes need to co-operate to manage and document the available stock through acknowledged maintenance of studbooks. This is necessary to assure that genetic diversity in the breeding stock is maintained.