Wattled Crane Recovery Programme
To supplement wild populations to ensure long-term survival of wattled cranes in South Africa
The Wattled Crane Recovery Programme plays a major role in ongoing efforts to prevent the local extinction of the wattled crane (Bugeranus carunculatus) in South Africa. Wattled cranes are the most critically endangered crane species on the African continent. Currently Red Data listed as Vulnerable, wattled cranes were once widely spread across Africa, but now occur in a vastly restricted range with only approximately 7000 individuals remaining in the wild. Some of the greatest losses of wattled cranes have occurred in South Africa where a 35% decline in population size over just two decades left the population Critically Endangered and facing a high risk of extinction in the wild. There are only approximately 250 individuals left in the country; mainly located in isolated pockets of the KwaZulu-Natal highlands. Recent genetic diversity studies have indicated that this sub-population is genetically distinct from populations in other African regions and relevant conservancies now recommend that South African wattled cranes be managed as a distinct population. A successful reintroduction/supplementation programme is vital to ensure their sustained future.
Concern over the decline of the species in South Africa, and its potential genetic uniqueness, led to the initiation of a Population and Habitat Viability Assessment (PHVA) workshop facilitated by International Union for Conservation of Nature's Conservation Breeding Specialist Group in July 2000, where it was determined that a captive breeding and release programme was needed to ensure the long-term survival of the species and thus the Wattled Crane Recovery Programme was initiated.
The Wattled Crane Recovery Programme aims to prevent the local extinction of the wattled crane in South Africa through two major objectives: 1) the maintenance of an ex situ breeding flock to serve as a genetic reservoir in the case of catastrophic extinction of wattled cranes in the wild, and 2) supplementation of the wild population through the reintroduction of isolation-reared fledglings into existing wild populations.
Wattled cranes typically lay one egg per clutch; however, a small percent of the females will lay two eggs per clutch. Even when two eggs are laid, only one chick is reared and the second egg is abandoned as soon as the first egg hatches. The Wattled Crane Recovery Programme is currently creating an ex situ breeding flock by collecting these abandoned eggs from the wild and costume rearing the resultant chicks to prevent human imprinting. All wattled cranes in the ex situ breeding flock and their progeny remain property of Ezemvelo KwaZulu-Natal Wildlife, the provincial wildlife conservation authority, and are managed through a strict set of guidelines and protocols to maximise reproductive capacity and prevent potential transmission of disease to the wild population.
Much remains unknown about the captive reproduction of wattled cranes, as worldwide efforts to breed this species in captivity have only proved marginally successful. Poor fertility remains a major obstacle to captive reproduction. The Wattled Crane Recovery Programme is currently attempting to modify standard crane assisted reproduction techniques for the wattled crane in an effort to overcome some of these challenges and make recommendations for the global ex situ management of this species. A dedicated wattled crane breeding centre has been created at Johannesburg Zoo's Conservation Breeding Centre in Parys, South Africa where assisted reproduction techniques will be applied in order to increase the number of fledglings available for release.
Once the creation of the ex situ breeding flock is complete, offspring of the captive population, along with any additional chicks produced from abandoned wild eggs, will be reared at the Bill Barnes Crane and Oribi Nature Reserve in KwaZulu-Natal and subsequently released into existing wild wattled crane flocks in an effort to bolster the wild population. The chicks will be reared utilising a technique known as "isolation" or "costume" rearing, which employs the use of human caretaker dressed in a crane costume who teaches the developing crane chicks social, foraging and predator aversion skills. Feasibility trials to assess the potential for supplementing the wild wattled crane population in South Africa using costumed-reared fledglings were conducted between 1995 and 2000. During the trails, a number of costumed-reared wattled cranes were successfully integrated into wild wattled crane flocks in KwaZulu-Natal.
Over the last several decades, extensive conservation measures have been undertaken in South Africa and 18 of the 21 priority projects identified during the 2000 PHVA have been completed; including extensive habitat preservation and restoration. Due to these extensive mitigation efforts, the wild population is now stabilising. However, without successful supplementation efforts, the wattled crane population in South Africa will very likely struggle to recover as wattled cranes have one of the lowest reproductive rates of the world's 15 crane species; producing only one chick per season with a less than 50% survival to fledgling rate. These challenges are further compounded by thinly scattered breeding sites that result in a high level of population fragmentation. Supplementation of South Africa's genetically unique wattled crane population will help decrease population fragmentation and secure a future for wattled cranes in one of the few politically and economically stable countries within their global range.
WAZA Conservation Project 05008 is implemented by Johannesburg Zoo, in partnership with the Endangered Wildlife Trust, African Association of Zoos and Aquaria and Ezemvelo KwaZulu-Natal Wildlife. Ten captive management facilities in South Africa participate in the breeding programme, including Amazona Endangered Parrot Breeding Centre, Hlatikulu Crane & Wetlands Sanctuary, Johannesburg Zoo, Mitchell's Park, National Zoological Gardens of South Africa, Treehaven Waterfowl Trust, Umgeni River Bird Park and Zabdiy-El Farm. The Wattled Crane Recovery Programme is a member of the IUCN Re-introduction Specialist Group.
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