THE Chinese alligator is critically endangered and in 2007 scientists introduced six reptiles to wetlands on Shanghai's Chongming Island. How are they doing? Zha Minjie and Zhao Wen report on a nighttime field trip.

Four small boats glide silently past reed-covered marshy banks on a clear September night on Chongming Island, searchlights sweeping the water surface ahead. Suddenly a small pair of eyes glow red in the light of a flashlight.

"I think I just saw a small alligator," gasps volunteer Wang Jiyi, suddenly remembering to lower his voice, since the animals have keen hearing. He points to the eyes, hidden where wetland reeds meet the water around 10 meters away.

As the boat is rowed closer, the eyes placed high on the head do not move as the yellow and black bands on the small creature's head become visible. In a long lens, Wang looks a wild, critically endangered Chinese alligator (alligator sinensis) in the eye.

"What a beautiful species," says Dr/Professor He Xin from Shanghai-based East China Normal University, who joined the night-time expedition. He estimates the young gator is little more than 10 centimeters in length. "So far it's still a cute baby."

It can eventually grow into a 1.2- to 1.7-meter-long adult if everything goes well, with no loss of habitat, no hunters or farmers and no water pollution.

This scientific alligator preservation "hunt" last Saturday was a search by experts and volunteers for the endangered reptiles that were released into the wild on Chongming Island for the first time in 2007. At that time six individuals, male and female, were released, some from a different gene pool of Chinese alligators in the United States.

From sightings of alligators, nests and broken eggshells since then, the indications are that the gators are doing well and breeding in their new home.

On this September night, volunteers and experts spotted 10 individuals. This is about time for them to start digging holes and hibernate for the winter. On September 7, 12 individuals were sighted and photographed. There may be duplicate sightings.

Chongming contains some of Shanghai's only wetland areas, and some of these have been reclaimed from development.

The Chinese alligator is one of only two alligators species in the world and by far the smallest. The other is the huge American alligators, alligator mississsippiensis, which is abundant in the southwest United States. Adult males grow 4 to 4.5 meters in length.

The Chinese alligator is native only to the lower Yangtze River Delta, notably Shanghai and Zhejiang, Jiangsu and Anhui provinces, as well as Lake Tai. It's on China's most-endangered list.

All alligators are crocodiles but crocodiles are not alligators. They have different-shaped snouts and teeth placements. Alligators have U-shaped snouts; crocodiles have narrower V-shaped snouts. Chinese alligators are dark, almost black in color, while American alligators are brown or olive. Chinese alligators are also armored on their bellies, unlike their American cousins.

Shy alligators

Despite their fearsome appearance, Chinese alligators are rather shy and not much of a threat to humans - but don't get too close, those big jaws are intended to crush.

The number of wild Chinese alligators dropped from around 500 in 1985 to less than 130 in 2003. The remaining number in the wild is estimated to be around 120, according to a recent census.

In 1979, the Chinese Alligator Breeding Research Center was established in Anhui, where the reptiles breed rapidly in captivity. The number of capitive Chinese alligators is estimated at more than 20,000 and rising. But there are problems in captivity - juveniles don't know how to dig caves or burrows to hibernate and they are used to waiting to be fed. Further, since the gene pool is limited, birth defects are increasing and quite a number of animals are not viable.

"Breeding centers around the nation are flooded with captive Chinese alligators, but the number means nothing if they are genetically degraded," says Shen Jiajun, marketing manager of Chongming's 6-hectare Dongtan Wetland Park.

Alligators have rarely been reintroduced to the wild, and one of the first attempts was made in the Dongtan wetlands.

Professor He remembers the scene more than five years ago when the six alligators, three from American zoos and three from Zhejiang - all equipped with radio transmitters - slowly crawled into a marshland pond. It was a joint project of Chinese and American scientists supported by the Wildlife Conservation Society and the Chinese government.

Shen says the three Chinese alligators from the US come from a different gene pool and can increase genetic diversity and the species ability to survive.

So far the alligators are doing well, as far as scientists can tell. They found food and dug burrows. Two died when they were caught in fishing nets but the remain later began to breed.

In October 2008, researchers found an alligator's nest in the middle of the release pond and there were 16 broken eggshells inside, indicating hatchlings. Since then, new nests and juveniles have been spotted, but the exact number isn't known.

Inside the wetland park, alligator food is not a problem, though the park itself struggles financially to survive, despite visitors.

"It's the perfect breeding area, with fish, crabs and other small animals, offering an ideal menu for the reptile," Shen says.

Still, much work remains to be done before the reintroduction program can be considered successful.

"The best outcome is a self-sustained wild population on this island," researcher He says. More reptiles may be introduced to the wetlands, he says.

The pictures taken on the recent night searches will be analyzed for indications of how the population is growing and the gender ratio.

"Everyone is delighted so far with all the preparation and research," Professor He says. He recalled the efforts of scientists, especially the late American conservationist, John Thorbjarnarson, who helped rescue many species from the brink of extinction.

"He told us that reintroduced alligators are best left alone and unbothered in the wild," he says.

This May six alligators were released in Chinese Alligator Breeding Research Center in Anhui, bringing the total released there to 51.