Kenya plans to poison a million crows

An estimated one to two million Indian house crows live off the Kenyan coast, and they are migrating deeper into Kenya. Kenya’s neighbors in East Africa and elsewhere are also troubled by the species, with some resorting to poisoning.

“It is time to eradicate this invasive species to halt its cumulative negative ecological and social impacts on the East African coast,” said John Musina, an ornithologist and conservationist at the National Museums of Kenya.

Wildlife officials in June described crows as “invasive non-native birds that have been a nuisance to the public for decades, driving native birds from their natural habitats and severely impacting local bird populations”.

The crow, known to scientists as Corvus splendens, is native to much of South and Southeast Asia. The slender, glossy black bird is about 40 centimeters (16 inches) long, with a large beak and a light gray neck ring.

They have spread further afield, either by ships or by being deliberately introduced in the belief that they help control rodents and trash.

‘Aggressive and opportunistic’

The crows were brought to the nearby island of Zanzibar in the 1890s to help with the then-British protectorate’s growing trash problem, and then spread along the coast, being first recorded in Mombasa in 1947.

In total, they are believed to have reached 36 countries outside their native range.

While in Asia they are kept in check by monkeys, snakes, birds of prey and rival crows, they appear to have no natural enemies in their new home, according to the Global Invasive Species Database (GISD).

Conservationists blame crows for decimating small native birds such as weavers and striated finches by tearing up their nests and attacking their eggs and chicks.

Dr Mwenda Mbaka, a veterinary public health and pest control expert, said: “House crows are very aggressive predators that are opportunistic. They prey on eggs, chicks and even adult birds of native species, which has led to a decline in local bird populations.”

Small reptiles, mammals and invertebrates also fall victim to crows, whose habit of preying on chicks and eggs poses a problem for free-range poultry farmers.

House crows also carry at least eight human diseases in their guts, but GISD says the link between these diseases and human transmission has not yet been established.