- Location :Anhui province, China
- Species status :Critically endangered
- Period :May 2011 - May 2016
The Chinese alligator (Alligator sinensis), one of the world’s most endangered crocodilians, and is the only species endemic to China.
It is listed by the IUCN as Critically Endangered and included within Appendix I of CITES.
Fossil evidence and literature on the subject suggest that the Chinese alligators were once widely distributed in the lowland areas and rivers of China. By the middle of the nineteenth century, they were present throughout the lower Yangzi River valley in southeastern China. Currently, Chinese alligators are now restricted to a few small isolated areas in southern Anhui Province and in adjacent Zhejiang Province. Recent field surveys suggest that not more than 120 alligators remain in the wild and the population continues to decline. The principal factor contributing to the decline of the species is habitat loss.
To increase the number of Chinese alligators in the wild, additional sites for the establishment of new populations will have to be identified and restored, and captive-bred alligators reintroduced. The technique of reintroducing crocodilians to their natural habitat has already proven successful in several countries. The Chinese government is now very interested in the reintroduction of the alligators. From 2006 to 2010, thirty-six captive- bred alligators were released at Gaojingmiao Forest Center in Langxi County in Anhui Province. They were all accurately measured by radio-telemetry. The reintroduced alligators have laid five nests, while forty-nine babies have hatched.
Research on the Chinese alligator’s habitat selection was performed during the whole of the re-introduction process and a considerable amount of habitat preference data was collected. The research team now intends to screen between three and five potential habitats along the lower Yangzi River and to reintroduce captive-bred Chinese alligators there using GIS as well as remote sensor techniques.
Selected captive-bred Chinese alligators will then be released at the chosen reintroduction sites. The Anhui Normal University research team expects that there should be over 300 alligators living in natural habitats within three to five years with very little human intervention. Should this objective be achieved, the species will have a high probability of survival and the risk of extinction would be greatly reduced. The implementation of this program will bring great hope for this emblematic species in China.
To determine which site is most suitable to release the Chinese alligator, it is necessary to understand what is needed for the survival of the species. Researchers at Anhui University analyzed the habitat of Chinese alligators and showed that bank shelter conditions, pH value of the water area, snail abundance, bamboo abundance, and water stability were significant elements in the survival of the alligators. Bank shelter condition was shown to be especially important. The observations in the field also confirmed this and released individuals tended to choose the edges of banks that were in good condition with significant vegetation cover.
The above results however referred mostly to microhabitats and a larger approach is needed in order to determine the Chinese alligator´s “ideal” habitat and factors such as human impact, landscape characteristics (slope, aspect) etc. should also be considered. Habitat suitable index modeling should then be used to help screen the potential habitat areas, together with maps from GIS technology, to help environmental managers make appropriate decisions. Remote sensors and GIS have provided further support for the establishment of the Chinese crocodile reintroduction model.
- K Bovee and JR Zuboy. 1988. Evaluation of habitat suitability, criteria. In Proceedings of the workshop development, volume 88, US. Fish, Wildlife Service, Biological reports
- BL Brooks and SA Temple. 1990. Hahitat availability and suitability for loggerhead shrikes in the upper midwest. American Midland Naturalist, 123: 75–83
- Gage H. Dayton and Lee A. 2006. Fitzgerald. Habitat suitability models for desert amphibians. Biological conservation, 132: 40–49
- Antoon de Vos. Crocodile conservation in India. 1994. Biological Conservation, 29(2): 183 – 189. ISSN 0006-3207. doi: DOI:10.1016/0006-3207(84) 90076-4.
- M Debeljak, S Dzeroski and K Jerina. 2001. Habitat suitability modeling for red deer (Cervus elaphus l.) in south-central Slovenia with classification tree. Ecological Modeling, 138: 321–330
- You-Zhong Dingand Xiao-MingWang. 2004. Factors influence the population status of wild Chinese alligators (Alligator sinensis). Biodiversity Science, 12 (3): 324–33
- You-Zhong Ding, Zheng-Huan Wang and Jian-ShengWu. Observation of activity in Chinese alligator released during an early period at Hongxing of Anhui. Zoological research, 25(1): 27–31, 2003.
- CK Dodd and RA Seigel. 1991. Relocation, repatriation and translocation of amphibians and reptiles: Are they conservation strategies that work? Herpetologia, 47(3): 336–350
- Roland F. Graf, Lukas Mathys, and Kurt Bollmann. 2009. Habitat assessment for forest dwelling species using lidar remote sensing: Capercaillie in the Alps. Forest Ecology and Management, 257: 160–167
- GJ Rolof and BJ Kernohan. 1999. Evaluating reliability of habitat suitability index models. Wildlife Society Bullet, 114: 287–304
- Henrik Skova, Elizabeth Humphreysb, Stefan Garthec, and Kerstin Geitner. 2008. Application of habitat suitability modeling to tracking data of marine animals as a means of analyzing their feeding habitats. Ecological modeling 212: 504–512
- PS Soorae. 2008. Global re-introductionperspectives: reintroduction case studies from around the globe. viii+284 pp, IUCN/SSC Re-introduction Specialist Group, Abu Dhabi, UAE
- Giacomo Tavecchia, Covadonga Viedma, and Miguel-Angel Bartolom Alejandro Martnez-Abran. 2009. Maximizing re-introduction success: Assessing the immediate cost of release in, a threatened waterfowl. Biological conservation, 14: 3005–3012
- JW Terrel. 1984. Fish habitat suitability index models. In Proceedings of the workshop, volume 85, U.S. Fish and wildlife service, Biological Reports.
- John Thorbjarnarson and Xiao-Ming Wang. 1999. The conservation status of the Chinese alligator. Oryx, 33(2): 152–159
- John Thorbjarnarson, Xiao-Ming Wang, Shao Ming, Lijun He, Youzhong Ding, Yuelong Wu, and Scott T. McMurry. 2002. Wild populations of the Chinese alligator approach extinction. Biological Conservation, 103(1): 93–102. ISSN 0006-3207. DOI: 10.1016/S0006-3207 (01)00128-8
- Simone Vincenzi, Graziano Caramori, RemigioRossi, and GiulioA. De Leo. 2006. A GIS-based habitat suitability model for commercial yield estimation of tapes philippinarum in a
- Mediterranean coastal lagoon (Cacca di Goro, Italy). Ecological modeling, 193: 90–104
- Rongsheng Wen. 2001. The rise and fall of Alligator sinensis and vicissitudes of environment. Nature Magazine, 22(1): 55–58
- Lu-Sheng Wu, Xiao-Bing Wu, Hong-XingJiang, and Chao-Lin Wang. 2005. Habitat characteristics of wild Chinese alligator (Alligator sinensis). Biodiversity science, 13(2): 156–161