Madagascar's political turmoil threatens the Indian Ocean island's rare wildlife, 13 international conservation groups said in a joint statement Monday.

The World Wide Fund for Nature, Conservation International and 11 other groups described armed men plundering lumber from national parks and smugglers taking more and more animals for sale on international markets. The groups also said illegal mining and slash-and-burn farming were increasing.

"These deplorable acts will only further impoverish the country and deprive future generations of the Malagasy people from their unique natural heritage," the statement said.

Madagascar's rain forests are home to species of plants and animals found nowhere else in the world.

James MacKinnon, senior technical director for Conservation International's Madagascar program, said in a telephone interview from the island that criminals were stepping into a void created because government officials have been distracted by politics.

Earlier this month, street protests brought down President Marc Ravalomanana. The international community has refused to recognize Ravalomanana's replacement, saying Andry Rajoelina's military-backed rise was unconstitutional.

Rajoelina's regime did not immediately respond to the conservationists" charges.

Madagascar has seen such political upheaval before, and it has been accompanied in the past by an increase in the pillaging of natural resources, MacKinnon said.

Mireya Mayor, a primatologist who has worked on Madagascar for a decade — and introduced its natural treasures to an international audience through National Geographic TV and blogs — said the plundering is worse than usual this time.

She said increased logging of old-growth rosewood trees in Marojejy National Park, a World Heritage Site, threatened the highly endangered Silky Sifaka, a lemur found only in and around the rain forests of Marojejy.

"Conservationists are a little bit at a loss as to what we can do," she said. "We are up against ... thugs."

In a message posted on their Web site earlier this month, Marojejy National Park officials said they were "with great sadness" closing the park to tourists indefinitely because of "lawlessness."

Mayor said that at a time when Rajoelina was facing sanctions, with Washington cutting all non-humanitarian aid, conservationists were trying to find funding for overwhelmed park security officers.

The crisis follows several years of progress, with new protected areas being created and more of the island's people being given a chance to benefit from tourism, MacKinnon said. Now, he said, there was "open abuse and pillaging" in even some of the most established areas.