A coalition of environmental groups says several hundred critically-endangered orangutans in a protected area of western Indonesia could be killed off by the end of the year if land clearing is not stopped immediately.

The warning, issued Wednesday in Jakarta, says satellite imagery shows forest fires in the 13,000-hectare Tripa swamp already forcing the powerful apes to the fringes of remaining forest area.

Environmentalist Graham Usher said just more than 12,000 hectares remain of the original 60,000-hectare Tripa peat swamp and forest in Aceh province. The rest, he said, has been divided up and degraded as palm oil companies drain the swamp land. He said a single prolonged dry spell — a normal occurrence in the region — will quite likely destroy the remaining forest and everything in it, including sun bears, tigers and other protected species — within months.

Analysts say the palm oil industry has grown to make Indonesia the world's top producer and exporter of the edible oil — a key ingredient in goods ranging from cooking oil to biodiesel, peanut butter, soap, biscuits and animal feed.

Last year, the United States forgave more than $30 million in Indonesian debt in return for stepped up forest conservation on Indonesia's Borneo island.

That agreement is monitored by the World Wildlife Fund, which said Indonesia ranks fourth in the world in terms of total carbon emissions. Scientists also said the Southeast Asian archipelago accounts for more than 14 percent of global deforestation — much of it driven by demands from palm oil producers seeking to plant trees.