Nature’s cleaning crew on verge of extinction

Friday October 14 2011

By MWANGI NDIRANGU ([email protected] )

It is a bird of prey associated with the virtue of patience. Gifted with a telephoto eye, it can drop from three kilometres in the sky at a speed of 120 kilometres per hour to the carrion.

And once on the ground, its colleagues will have read the signs and will arrive at the scene to devour the carcass within minutes, reducing the risk of disease infection to animals and humans.

While other scavengers like hyenas or jackals take hours, or even days, before clearing a carcass, the vulture consumes all the meat at high speed.

Its role in the ecosystem has been downplayed for years, until recently. Conservationists now believe the vulture is the ultimate indicator of an ecosystem’s health.

“Vultures are the only animals that survive on scavenging 100 per cent. Through clearing carcasses, they prevent the accumulation of harmful bacteria that may end up getting to other animals or even humans,” says Mr Erastus Kanga, an assistant director of Kenya Wildlife Service.

For all the good cleaning work it does in the ecosystem, however, the vulture is in grave danger of extinction.

A study carried out at Mpala Research Centre in Laikipia indicates that as the vulture numbers plummet, the number of mammalian scavengers (hyenas and jackals) is increasing.

This adds up to the potential for increased levels of disease transmission. The International Vulture Awareness Day was marked last week with a focus on the falling vulture numbers.

With a mortality rate of 30 per cent recorded in the last two years, and the slow reproduction rate, Kenyans were urged to prevent this bird from disappearing.

Of the eight vulture species found in Kenya, six are threatened with extinction with a decline in population of between 50 and 70 per cent in the last decade, says the chairperson of Raptor Working Group of Nature Kenya, Darcy Ogada.

Ms Ogada attributes the rapid decline of vulture’s population to unintentional poisoning, witchcraft and their slow rate of reproduction.

“Pastoralists are known to poison carnivores like lions and when the vultures consume the carcass, they die en masse.

A recent case was recorded in Athi River where 180 birds died after consuming a poisoned carcass,” Ms Ogada says.

“It takes up to two years for one bird to produce a chick. It means replacing vultures that die through such poisoning incidents may take years,” Ms Ogada observes.

She says that in Tanzania, vultures are killed and their heads used in witchcraft rituals.

“What is worrying us is that the birds are highly migratory. They can move from here to Sudan and Tanzania and end up being killed in those places for witchcraft rituals,” she says.

Though the actual population of the birds is yet to be established, efforts to track them down have been made in the past, and it is here that their migratory patterns and their high mortality rate was established, Ms Ogada says.

This year’s theme — the role of vultures in maintaining the cycle of life — highlighted the importance of the birds in helping landowners dispose of carcasses they would otherwise have to bury or burn.

This year, the event was marked at Ol Pejeta Wildlife Conservancy in Laikipia, where students were involved in the campaign to influence attitude change towards the harmless bird.