Several cases of deliberate of animals using carbofuran pesticide have been reported in recent years in various parts of Kenya, especially in areas where the animals are increasingly competing for living space and territory with humans. But wildlife conservationists became particularly alarmed earlier this month when wildlife officials in the world-famous Masai Mara National Park discovered five dead , which died after grazing on vegetation containing traces of carbofuran.

The hippo also led to the discovery of four lions suffering from acute paralysis. The lions had fed on one of the dead hippos and test results later showed trace amounts of carbofuran in the lions' .

The former head of the government-run Kenya Wildlife Service, Richard Leakey, who now runs a local wildlife charity called Wildlifedirect.org, says it is not clear how carbofuran made its way into the park's .

But he says nomadic people living near the Masai Mara may have used the chemical to poison predators, not knowing that killing animals with carbofuran often to secondary poisonings that have the potential to entire wildlife populations.

"A small on meat will kill lion, leopard, cheetah, hyena, jackal, vulture, and it is a much bigger problem than the conservancy," said Leakey. "A lot of the nomadic people, who are fed up with the constant harassment of their [live]stock and the predation they are suffering from, have learned to use carbofuran."

"To an extent, it is a reflection of the fact that wildlife-human conflict has grown in intensity and the Kenya wildlife authority is simply not up to giving the assistance people are looking for by removing animals through . As a consequence, and pastoralists have just taken the law into their own hands and said, 'Well, if you will not remove the lions, we will kill them," he added.

Sold in Kenya under the brand name of Furadan, carbofuran is popular with farmers not only because it is an effective pesticide, but because it is and available in many stores throughout the country.

Leakey says one recent study confirmed that fishermen in Lake Victoria in western Kenya have begun using carbofuran to catch fish, raising serious questions about the health that carbofuran-contaminated food poses to people.

Exposure to the chemical can cause , dizziness, confusion and in high doses, respiratory paralysis and death. The European Union has already banned the sale and distribution of carbofuran and in January, the U.S. Environmental Protection Agency determined that products containing carbofuran can cause adverse on humans and the environment.

Conservation groups in Kenya have called for an immediate ban on the sale, distribution and the importation of the chemical. But Kenya's Pest Control and Products Board say it is still not convinced that carbofuran a danger to humans and wildlife.