Kenyan game rangers on Wednesday began rounding up thousands of zebras and other herbivores to be moved to a reserve where starving lions have been attacking livestock.

The spectacular nationwide operation, launched in Soysambu conservancy by the Kenyan Wildlife Service (KWS), is due to last until the end of the month in what will go down as one of Africa's largest ever animal translocations.

Shortly after daybreak, rangers in helicopters rounded up startled galloping zebras into a large V-shaped tarpaulin enclosure.

The animals at the narrow end of the enclosure were allowed through into an adjoining pen and from there they were loaded onto trucks, with each carrying some two dozen zebras.

KWS aims to move some 7000 animals in all, zebra and wildebeest. At least 88 zebras had already been captured on Wednesday, hours into the operation.

Around 1000 animals will come from Soysambu, near the Rift Valley city of Nakuru, a private conservancy owned by Delamere Estates. The remainder will be taken from several other reserves.

A refuge for animals

The operation, costing 103 million shillings ($1.3-million), will be carried out in four phases and run to 28 February, KWS officials said.

The plan is to restock Amboseli, some 300 kilometres (186 miles) from Soysambu, with natural prey so as to prevent hyenas and lions from attacking livestock in homes around the park.

Charles Musyoki, a scientist with KWS explained that Amboseli park is a "dry season feeding refuge for herbivores" where animals jostle around watering holes and patches of pasture then leave when rainfall resumes in the regions they migrated from.

But last year the animals did not move out of the park due to the prolonged dry spell.

"We lost significant numbers of wildebeests and zebras. Over 60 percent of zebras and wildebeests were lost in that ecosystem," Musyoki said.

The attacks on domestic animals came after Amboseli's predators ran out of prey after the massive drought-related deaths of herbivores.

"The deaths created an imbalance in the number of carnivores and herbivores in the park resulting in a shortage of the lions' and hyenas' normal food," KWS spokesperson Paul Udoto said.

Reasons behind the imbalance

"It is expected that the restocking will restore the balance of animals within the park and reduce the lion and hyena attacks on livestock," Udoto explained.

In August, KWS said Kenya was losing 100 lions each year as cattle herders killed them in retaliation for attacks on their stock.

But habitat destruction, disease and the rising human population also played a role in the drop of their population to the current 2000 from 2749 animals seven years ago.

Last year's drought was one of the worst in years across eastern Africa.

Kenya's last massive animal transfer was in 2005, targeting 400 elephants from an over-crowded coastal reserve to a vast inland park, but that had to be halted due to drought that threatened their survival in their new home.

The translocation was dubbed "the single largest translocation of animals ever undertaken since Noah's Ark."

Wildlife is one of Kenya's main tourist attractions while tourism ? the country's top foreign currency earner ? is still recovering from the ravages of the violence that broke out following the disputed December 2007 elections.