Chinese Crocodile Lizard
Southern China and northeastern Vietnam
Found near slow-flowing streams or ponds in evergreen and bamboo forests.
This small grayish-brown lizard has an orange to red colored throat and sides. On the head, the scales are plated, with ridged scales behind the eyes. Its most distinctive features are the two rows of enlarged, bony scales running down its back and muscular tail. These resemble the scales on a crocodile’s tail, giving the lizard its name.
Coloration is variable within sexes. The males are generally more colorful then females. Colors intensify during the breeding season. In general, dorsal or back colors of various shades of brown from head to tail are the dominate color in both sexes. Ventral or belly colors vary from yellowish tan to light orange. Newborn crocodile lizards are uniformly deep brown, with a light tan snout and forehead.
Usually only one Chinese crocodile lizard will inhabits a pond. They prefer thick vegetation with tree branches overhanging the waterholes. This provides them with shade and sleeping places. Crocodile lizards will spend long periods of time out of the water, frequently remaining motionless for hours in a "metabolic pause." During this time they do not respond to any surrounding stimuli. The indigenous people call them "the lizard of great sleepiness". Observations of the Chinese crocodile lizard remaining immobile for hours, occasionally for days, led to the belief that it could cure insomnia. Their collection and consumption for traditional medicinal use has most likely been going on for hundreds of years.
It is semi-aquatic and is comfortable in shallow water or in overhanging branches where it waits for its prey. The Chinese crocodile lizard is able to dive beneath the surface and remain motionless or move around underwater for long periods of time. To do so it is able to reduce its respiratory rate drastically. When threatened, the crocodile lizard will flee into the water. It swims using its powerful tail and is a strong swimmer. If caught, it becomes a fierce fighter struggling violently all the while defecating, hissing, and biting to become free. They are largely diurnal, active during the day, with activity concentrated in the morning and evening, but they rarely engage in intense activity.
When the weather turns colder, the lizard will hibernate. Although usually solitary, it congregates with other lizards in rock crevices or tree holes before hibernating from November to March. Hibernation is triggered when the water temperatures drop below 60 degrees Fahrenheit. Hibernation ends in March when the pond water warms.
Chinese crocodile lizards reach sexual maturity between two and three years of age. Breeding takes place from July to August. Unlike other lizards that may have elaborate courtship behaviors, there is very little courtship behavior involved in their breeding season. Males have been documented to become brighter to attract the females. The females are pregnant for 8 months and she gives live birth to two to 12 offspring. The young are very active at birth, feeding and swimming almost immediately. Neither parent cares for the babies. The young remain at their birth pond area for a few weeks and the leave to seek their own pond or stream to defend.
Semiaquatic, the Chinese crocodile lizard is able to submerse and remain motionless or move around underwater as long as a half an hour, before returning to the surface to breathe. This shut-down mechanism could aid in calorie conservation, an adaptation to the temperature drastically cooling in the region.
Habitat loss is the biggest threat to this species. As areas are logged, ponds and streams dry up and reduce the amount of ground cover available. This makes the lizard more vulnerable to predators such as raptors. In 2003, a new population of crocodile lizards was found in Vietnam; however it is now almost extinct due to illegal logging. This lizards beautiful appearance and docile nature has also led to its decline in the wild. Many people seek them as pets. In the 1980’s, large numbers were exported to Europe and America, further decimating already small populations. In 1990, the lizard was placed under CITES regulation in Appendix ll and virtually no imports of wild-caught specimens have since occurred in Europe or the United States.
In 1996, the Association of Zoos and Aquariums Lizard Advisory Group established long-term goals: (1) to improve the status and reproduction of rare and endangered lizards in North American collections; (2) to encourage the need and opportunity for captive-breeding programs; (3) to establish a worldwide network of field, zoo and conservation biologists and provide a forum through which this network can communicate. The crocodile lizard was placed in the high priority category to establish sustainable captive populations.
In 2008, it was estimated that only 1,000 to 2,500 individuals remained in the wild but due to their rugged habitat and reclusive nature, accurate counts are not available.
|Did YOU Know?|
|They are called “lizard of great sleepiness” because of their ability to remain motionless for hours.|