Genes reveal new subspecies of tiger

December 7, 2004

GAINESVILLE, Fla. — An international group of researchers has found a new subspecies of tiger — and they did it by delving into DNA rather than plunging into the jungle.

A genetic analysis of tigers from across Asia revealed that tigers roaming the wilds of the Malaysian Peninsula are substantially different from those in the rest of the continent — different enough to be considered a new subspecies. The finding, published today in the journal Public Library of Science Biology, could affect efforts to save the endangered cats.

“This adds a new wrinkle to tiger conservation,” said Mel Sunquist, professor of wildlife ecology at UF’s Institute of Food and Agricultural Sciences and a co-author of the study. “We found that a single endangered subspecies, the Indochinese tiger, is actually two subspecies.”

“Each of those subspecies probably has a population that numbers in the hundreds, and each needs to be protected,” he said.

Sunquist was one of more than a dozen researchers who participated in the study, which examined blood and tissue samples from 134 tigers captured in locations across Asia. The study, led by geneticists at the National Cancer Institute, aimed to settle the question of how many subspecies of tiger exist in the wild.

Biologists traditionally have recognized eight subspecies of tiger, including three that were wiped out by hunting and habitat destruction in the 20th century. Among those traditionally identified species was the Indochinese tiger, believed to be a single group of about 1,700 cats found in Southeast Asia.

The new study splits that subspecies into two: the Malayan tiger, found on the Malaysian Peninsula, and the northern Indochinese tiger, found in areas ranging from Myanmar to extreme southwest China. The researchers say a long period of geographic isolation likely led to Malayan tigers developing genetic distinctness from their northern cousins.

Biologists traditionally use physical characteristics such as skull size, coloration and stripe pattern to distinguish one tiger subspecies from another, but the Malayan and northern Indochinese subspecies are nearly identical in appearance, Sunquist said.

Estimates of tiger population vary widely, but Sunquist said there likely are 800 to 1,000 Malayan tigers and a roughly similar number of northern Indochinese tigers left in the wild.

“The finding will affect future recovery efforts for both subspecies,” Sunquist said, “Because wildlife officials will now have to consider managing each subspecies as a unique and smaller population.”