Position of Burrow Entrances in Wild Chinese Alligators

The burrows of Chinese alligator (Alligator sinensis) were surveyed in Anhui National Natural Chinese Alligator Reserve in four periods within Jul.-Oct.from 1999 to 2002.Of the found burrows,24 were in use,and 16 were deserted.Five environmental variables regarding the positions of the burrow entrances were measured.A large percent (87.5%) of entrances were located about the water surface (0-0.5 m and <0 m);85.0% were within 5 m from the water body;32.5% were towards north;72.5% were vegetation-covered less than 70%;and 42.5% were within 100 m from villages.Factors such as the height above water surface,distance to water body,entrance direction,and degree of shelter contributed for 76.6% of the variance in total,and they were in descending order in the contribution.The convenience entering water body is the main factor for Chinese alligators to select the entrances.