The panda of the lizard world

Posted by: Diane Yoshimi, Zookeeper, with Linda Uyeda, Zookeeper

Recently born Chinese crocodile lizard. Photo by Ryan Hawk/Woodland Park Zoo.

Woodland Park Zoo recently had two female Chinese crocodile lizards (Shinisaurus crocodilurus) give birth to two litters of 11 babies in total. The crocodile lizard is an unusual reptile that gives birth to young after 9 to12 months of gestation. The newborn babies, weighing approximately 4 to 6 grams, are independent at birth and litter size ranges from 1 to 9. Since WPZ acquired a pair in 1993, there have been 70 crocodile lizard offspring born at the zoo. In December 2010 there were 115 individuals living in 22 North American institutions held in a managed program, meaning a studbook keeper recommends which individuals should be bred in order to maintain genetic diversity in the captive population.

Adult Chinese crocodile lizard (left) in a tank next to a baby Shinisaurus (right). Photo by Ryan Hawk/Woodland Park Zoo.

The Chinese crocodile lizard is an endangered lizard found in the Guanxi province in Southern China and in 2002 previously unknown populations were discovered in northern Vietnam. This species is semi-aquatic and lives in creeks between 200–700m in altitude surrounded by broadleaf trees and conifers. This lizard has become severely endangered due to collection for the pet trade and for food, and from habitat destruction. The total population of Shinisaurus in China declined from 6,000 in 1978 to 950 in 2008 and now are listed as a CITES Appendix II animal (vulnerable) granted protection as a category I species under the Wild Animal Protection Law in China.

Chinese crocodile habitat. Photo by Jin Li Wei.

Zookeeper Linda Uyeda and I recently attended the Daguishan International Symposium on the Protection and Breeding of Shinisaurus in Hezhou, China. It was a rare opportunity for us to share data from our breeding program with other scientists in one of the range countries of this species. The aim of the symposium was to increase habitat protection and public awareness, and to promote the breeding and eventual re-introduction of Shinisaurus into the wild. We learned from Shinisaurus researcher Dr. Zheng-Jun Wu that there are several striking differences between the breeding behaviors of the lizards at Woodland Park Zoo and the husbandry parameters we maintain in comparison with the crocodile lizard program in China. For example, our lizards are kept solely indoors so the time of year at which they breed and the growth rate of the young are significantly different from that of Shinisaurus living outdoors in China. Our lizards also reach sexual maturity much earlier, as early as 13 months, due to the rapid growth of the young.

Symposium attendees viewing Chinese crocodile lizard breeding enclosures. Photo by Linda Uyeda/Woodland Park Zoo.

Attending this conference gave us the opportunity to learn about conservation efforts in China and—the highlight of the trip—to see Shinisaurus habitat at the Daguishan Crocodile Lizard Nature Reserve and to see lizards at the Beilou Crocodile Lizard breeding station. We learned a great deal about their status in the wild, the husbandry and breeding of Shinisaurus in China, and the additional steps the Chinese government would like to take to protect this species. This gathering of Chinese scientists and government officials underscores the serious threats to this species which we heard referred to as the reptile equivalent of the giant panda!

Adult Shinisaurus at Woodland Park Zoo. Photo by Ryan Hawk/Woodland Park Zoo.

The conference was also attended by Michael Zollweg of the Zoological Society for the Conservation of Species and Populations in Germany, who had visited the research station earlier this year. He shared information on the status of Shinisaurus in Europe and we spent much time comparing notes on our experiences with this species. A particularly interesting item in his presentation was that a 48-million-year-old lizard fossil from Wyoming, Bahndwivici ammoskius, was found to be nearly identical anatomically to Shinisaurus, emphasizing the ancient nature of this fascinating lizard. Michael was a source of not only valuable husbandry and natural history information on Shinisaurus, but also of useful sight-seeing information. We saw many remarkable things during our stay in China but the hospitality of our hosts and their dedication to this species are the things we’ll remember most.

Close up of baby Shinisaurus born at Woodland Park Zoo. Photo by Ryan Hawk/Woodland Park Zoo.

The eleven baby Shinisaurus born at Woodland Park Zoo this year are currently not on view but will be placed on display when they are a little larger (at present they are each only about 5 grams). You can see the two female Shinisaurus mothers on exhibit in the zoo’s indoor Day Exhibit.