At-risk Alligators

Endangered Chinese alligators face a new challenge as the Three Gorges Dam begins to alter their habitat

Despite their timid nature, Chinese alligators (Alligator sinensis) have historically been associated with the mythical Chinese dragon. Unfortunately, this affiliation has not saved the species from human impact. Now the most critically endangered crocodilian in the world, the Chinese alligator has already faced significant habitat loss as marshlands have been converted into rice paddies or residential areas. However, on June 1, their habitat took another hit when the Three Gorges Dam closed for the first time, dramatically altering the water flow patterns in the lower Yangtze Valley, where the last 130 wild alligators live.

Hoping to save this species from extinction, the Chinese government has been working with the Wildlife Conservation Society on a captive breeding program, which has produced thousands of captive Chinese alligators. However, until recently, none of these animals had been reintroduced to the wild. On June 5, just days after the controversial dam closed, biologists released the first three captive-bred alligators into a pond in China's Anhui Province, which contains a few wild alligators. They are hopeful that the introduction will create new breeding opportunities. However, they aren't sure how the resident alligators will respond to their new neighbors, or how either group will be affected by the Three Gorges Dam.

Tour boats have long operated on the Three Gorges, consisting of the Qutang Gorge, 8 km long, the Wu Gorge, 44 km long, and the Xiling Gorge, extending 66 km. Photo: www.chinavista.com

 

The Chinese alligator (Alligator sinensis) is one of just two alligator species in the world. It diverged from its larger American counterpart at least 20 million years ago. Photo: John White
This Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) image from NASA shows a 65-km stretch of the Yangtze River. In this image, red represents vegetated land surface and the light blue ribbon of pixels running left to right is the Yangtze River. Blue-green pixels show exposed land surfaces. In the yellow box is the construction site of the Three Gorges Dam, the world's largest.
Photo: NASA
 

Chinese alligator (Alligator sinensis).
Photo: Wildlife Conservation Society