Puppets Help Raise Africa's Abandoned Hornbill Chicks
Leon Marshall in Johannesburg
for National Geographic News
|August 22, 2005|
Researchers hoping to increase the breeding rate of southern Africa's
increasingly rare ground hornbill have taken to feeding abandoned chicks
with puppets disguised as the birds' parents.
The faux foster mother may seem real to the ground hornbill chick. But inside the puppet head is a human hand trying to save the chick and its species from sliding to extinction.
Ground hornbills lay up to three eggs at a time, but they feed only one chick. Conservationists collect remaining hatchlings that are otherwise left to starve and hand-feed them.
The volunteers use tweezers for a beak and don a sock for a glove that is painted to look like a ground hornbill's head.
The human foster parents also wear cloaks over their heads to gaurantee chicks do not associate feeding with humans. This is to ensure the chicks do not remain dependent on people to feed them when they are released back into the wild.
The technique of hand-rearing ground hornbill hatchlings is part of a wide-ranging project in South Africa to grow the numbers of the turkey-size species. Together with its slightly different looking African cousin north of the equator, the bird is the largest of the hornbill species.
There are estimated to be only about 1,500 of the southern ground hornbill (Bucorvus leadbeateri) left in South Africa, although there may be a fair number more in the wider southern African region, said Kerryn Morrison, manager of the Ground Hornbill Working Group.
The group was launched last year by the Endangered Wildlife Trust, a southern African nonprofit dedicated to the conservation of endangered species and habitat.
Hornbills More Threatened Than Thought
The bird species has been classified as vulnerable in the Eskom Red Data Book of Birds of South Africa, Lesotho and Swaziland. But a population and habitat viability assessment workshop held near Kruger National Park in February this year found that the southern ground hornbill was a lot more threatened than previously thought.
Experts concluded that South Africa could lose its ground hornbills in the near future unless radical action was taken.
Morrison said the Ground Hornbill Working Group was working with the Red Data assessors of the World Conservation Union (IUCN) on whether to change the bird's status to "endangered."
Alan Kemp, research associate of the Percy FitzPatrick Institute of African Ornithology in Cape Town, South Africa, has researched the species extensively. He said one of the big reasons for the bird's plight is its slow and complicated breeding habits.
The birds are "cooperative breeders," Kemp said. "They move about in groups that have only one alpha male and female, which do the breeding, with the rest helping to feed the young," Kemp said.
Breeding couples are generally able to successfully fledge a chick only once in nine years. "It almost seems their equation is: 'Only breed as fast as you die,'" Kemp said.
Ground hornbills can live up to about 50 years. When an alpha male or female dies, another steps in to take its place.
Mostly males stick to a group and help feed the young, which remain dependent on them for food for up to two years after leaving the nest. Females tend to branch off, often forming their own coalitions to which they attract a male to set up a breeding couple, Kemp said.
Anne Turner heads the volunteer Ground Hornbill Project, which collects rejected hatchlings and feeds them. She said, "The chicks need an enormous amount of food. They reach the size of a grown bird within three months. The parents have a tough time coping even with only one for the three months they have to bring it food in the nest."
This is where human foster parents enbter the scene with their hornbill-like apparel, a method developed by the Santiago Zoo in Chile.
Turner's group has its headquarters at a private game reserve called Mabula, in South Africa's Limpopo Province about a 100 miles (160 kilometers) north of the capital city of Pretoria.
The group has a regional map showing ground hornbill nesting sites, which are usually in cavities in big trees. The map has been compiled with the help of game rangers, local communities, and farmers, who also notify them when a ground hornbill goes to nest.
The group keeps a close watch on nests because volunteers have three days at most to save rejected chicks.
"We feed them in silence in the open where all they hear are the sounds from the surrounding bush," Turner said. "We do this to prevent confusion when, at six months, we put them back with groups of hornbills in the wild which have to take over their feeding, as normally happens with fledglings on leaving the nest."
The hand-reared chicks are fitted with transmitters to keep track of their movementsand to help recapture the fledglings for additional feeding if the hornbill group fails to nurture them.
Habit of Breaking Windows
Turner says major causes of the birds' decline, in addition to their slow breeding, have been extermination by farmersthe birds have a habit of breaking windows.
This happens particularly during breeding season. Ground hornbills are territorial, and if they see their reflection they think it is an intruder and attack it, smashing the glass.
Ground hornbills are largely carnivorous, eating grasshoppers, beetles, mice, rock-rabbits, snakes, and lizards. The birds are often poisoned when they pick up shreds of meat, which farmers put out to kill jackals and caracals. Whole groups of birds may be wiped out this way.
Fortunately, says Turner, the tide may be turning for the species.
With the growth of ecotourism in southern Africa, many stock and crop farms have been turned into game ranches and conservancies.
Add to that the fact that people generally have become more conservation conscious. Local residents now actively assist in looking after ground hornbills. There is even a phone number for people to call to report problem hornbills, to be caught and relocated.
Many of the big trees in which the birds nest have been cut down outside reserves like Kruger National Park. As a result, the hornbill project has to provide young hornbills with human-made nests. This is done through a program which simultaneously serves as a poverty-relief scheme. The nests are commissioned and bought from a small rural community.
Rescue efforts for hornbills should get a boost from the 4th International Hornbill Conference, which is to take place at Mabula, South Africa, from November 6 to 9 this year.
The convener is Alan Kemp, of the Percy FitzPatrick Institute of African Ornithology, who says this is the first time the conference is being held in Africa.
The previous three conferences have all been held in Asia, where good progress has been made with the conservation of Asia's species of hornbill. Success there has been largely achieved through active management of the bird and its habitat, which is also the theme chosen for the South African conference.
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