KUALA LUMPUR, Apr. 17, 2008 (Reuters) — Borneo's mysterious pygmy elephants may be the descendants of Javan elephants accidentally saved from extinction by a local sultan several centuries ago, the conservation group WWF said on Thursday.

Pygmy elephants, so called because they are smaller and less aggressive than mainland Asian elephants, number perhaps 1,000 today and live in lowland forests in Borneo that are shrinking under the threat from timber, rubber and palm oil plantations.

With their larger ears, more rotund features and longer tails, the animals differ from other Asian elephants and scientists have long questioned why they never spread to other parts of the island, the WWF said.

New research published on Thursday supports a long-held local belief that the elephants were brought to Borneo centuries ago by the Sultan of Sulu and abandoned in the jungle, it added.

"If they came from Java, this fascinating story demonstrates the value of efforts to save even small populations of certain species, often thought to be doomed," Christy Williams, of the WWF's Asian elephant and rhino program, said in a statement.

The Sulu elephants are thought to have originated in Java, where elephants became extinct some time in the period after Europeans arrived in South-East Asia, the WWF said.

"Elephants were shipped from place to place across Asia many hundreds of years ago, usually as gifts between rulers," the statement quoted Malaysian forester Shim Phyau Soon as saying.