A pair of rare Komodo dragons, the largest lizard on Earth, are settling into their new home at the National Zoo, where curators hope to breed "this marvelous species" - although they have yet to determine if they have one male and one female.

A gift from Indonesia, the zoo's new dragons are two of the approximately5,000 Komodo dragons still in existance, zoo officials said. They are the only members of the species, known as Varanus Komodoensis, on exhibit in the Western Hemisphere.

"We brought the pair here with the intention of making concerted efforts to breed this marvelous species," said zoo curator Dr. Dale Marcellini. "We realize that in order to build a breeding program, we will have to study the animals closely and develop a deep understanding of their habits."

Although the dragons were presented to the zoo in early July as a male and female pair, Marcellini said it has been difficult determining their gender.

"There are ways of finding out, but they require anesthetizing and I haven't wanted to risk it yet," he said.

When adults do breed, they lay about 20 eggs, most of which hatch.

Marcellini said the 4- to 5-year-old dragons, Friendty and Sobat, "get along well" and should be mature enough to breed. Zoo officials believe Friendty is a female and Sobat a male.

Although the ferocious-looking lizards "are relatively laid back and calm" most of the time, Marcellini said when the dragons know it is feeding time, they charge toward their meal.

Preying on small deer, pigs, brush turkeys, rats, and dead animals, wild adult Komodos may weigh up to 200 pounds and grow up to 10 feet long.

While Friendty measures in at 6-feet and Sobat at 4 feet, 1 inch, both dragons are young adults and have room to grow.

The granular, bead-like scales that cover Komodos form a multi-colored skin of brown, gold, gray and green shades.

Komodo dragons are "cold blooded," meaning they do not heat their bodies internally. Marcellini said Friendty and Sobat enjoy sitting in the sun and soaking up heat.

The zoo will install supplementary heating to warm them in the winter.

Friendty and Sobat were hatched in the wild on Flores Island in the Indonesian archipelago and then brought to the Raganuan Zoo in Jakarta.

Most Komodo dragons live in a protected wilderness area established by the Indonesian government in 1965 on the island of Komodo.

Marcellini said a pair at the zoo in Surabaya, Indonesia, bred six years ago and six of their offspring survived, but he added that such a rate of success is highly unusual.

While the number of Komodo dragons remains steady, National Zoo spokesman Robert Hoage said that increased tourism and commercialism on the handful of Indonesian islands where they dwell could threaten the species.

For centuries the dragons survived on a few islands in the Indonesian archipelago that were not conducive to human inhabitation.

Westerners were unaware of these huge reptiles until 1912 when Dutch Major P.A. Ouwens, director of a botanical garden on the Indonesian island Java, heard rumors of a giant "terrestrial crocodile."