A Brazilian priest who blames ethanol production for a plague of pigeons outside his cathedral is threatening to set loose hawks and monkeys to frighten the birds away.

Environmentalists warned Tuesday that the scheme would break Brazilian law, but the priest seems unrepentant.

"I know that these actions are prohibited," the Rev. Francisco Jaber Zanardo Moussa said in a statement. "But I don't care, I'll do everything I can to promote my people's well-being."

The priest said the predators should frighten away a flock of 60,000 pigeons that have been forced from their natural habitat by the area's booming sugarcane plantations. He said the pigeons dirty the town's central plaza and could spread serious diseases in Ribeirao Preto, a city of 500,000 people in southeastern Brazil.

But Eliana Velocci, of Brazil's environmental protection agency, Ibama, said there are only 25,000 pigeons in the square, and that introducing predators to scare them away would violate a law prohibiting the release of wild animals in urban areas.

"We need to find another solution," she said.

The priest and local authorities initially wanted to use a repellant that reportedly helped nearby cities fight their own booming pigeon populations, but Ibama nixed that idea as well, saying the chemical has not been approved by health authorities.

Authorities blame the pigeon explosion on the growing number of sugarcane plantations that supply the raw material used to produce ethanol. Brazil is the world's No. 1 sugar producer and exporter, and the leading exporter of ethanol made from sugarcane.

"When they make room for sugarcane fields, they eliminate the pigeons' habitat and they flock to the city," said city council member Gilberto Abreu. "They keep saying ethanol is this great thing, but forget to think about the problems it is causing."