Satellite tracking of pygmy elephants has found that the endangered animals — unique to the island of Borneo — are under threat due to logging and commercial plantations encroaching on their habitat, conservationists said Thursday.

A World Wildlife Fund study, based on two years of satellite tracking, found that pygmy elephants thrive best in forests on flat lowlands and in river valleys — the same terrain preferred by loggers and oil palm plantations.

About 40 percent of forest in the Malaysian state of Sabah, where most pygmy elephants live, has been lost to logging, conversion for plantations and human settlement over the last four decades, WWF said.

• Click here to visit FOXNews.com's Natural Science Center.

Very little was known about pygmy elephants until a chance DNA analysis in 2003 revealed them to be a distinct subspecies of Asian elephants, which triggered a new effort to conserve them.

In June 2005, the WWF set in motion a landmark project to track pygmy elephants in the rain forests of Sabah by placing collars fitted with transmitters around the necks of five elephants, known to be leaders of their herds.

The collars beamed their locations via satellite to a WWF-Malaysia computer as often as once a day in the first study of its kind, providing valuable information about the elephants' grazing habits and movement patterns.

Data gathered so far reveals there are probably not more than 1,000 pygmy elephants left in Sabah — less than the 1,600 or so estimated previously.

The study revealed that pygmy elephants prefer lowland forests because there is more food of better quality.

"The areas that these elephants need to survive are the same forests where the most intensive logging in Sabah has taken place, because flatlands and valleys incur the lowest costs when extracting timber," said Raymond Alfred, head of WWF-Malaysia's Borneo Species Program.

The study also showed that elephants' movements are noticeably affected by human activities and forest disturbance. It found that some of the elephants were trekking five times as far as they normally would each day in search of food.

The loss of habitat brings them into more frequent contact with people and cultivated land, generating conflict with humans who sometimes capture or poison them to protect their farms.

While pygmy elephants can live in logged and secondary forests, it is crucial that their remaining habitat is managed in a sustainable manner and not converted into plantations, the WWF said.

Logging in elephant habitat should only occur if there is a long-term forest management plan in place, and oil palm plantations should be established on degraded, non-forested land devoid of elephants and orangutans, it said.

Malaysian officials could not immediately be reached for comment, but in the past they have accused Western activists of trying to undermine the palm oil industry by claiming that forest clearing in Malaysia and Indonesia is threatening wildlife.

The government says most palm oil plantations are established where forests have already been cleared for other crops.

Alfred said an initiative aimed at conserving 92,650 square miles of rainforest straddling the border between Brunei, Indonesia and Malaysia should ensure that most herds will have a home in the long term.

Adult pygmy elephants stand up to 8 feet tall — a foot or two shorter than mainland Asian elephants.

They are more rotund and have smaller, babyish faces with longer tails that reach almost to the ground. They are also less aggressive than their Asian counterparts.

Though smaller than its cousins, an adult pygmy elephant can still devour up to 330 pounds of vegetation each day. One of their favorite treats is the large, thorny and pungent durian fruit, which they often roll in mud to gulp it down whole, spikes and all.