Primarily Observation of Breeding Population of Great Frigatebirds (Fregata minor) on Dong Island of Xisha Archipelago

A survey on bird resources of Xisha archipelago was carried out in March-April of 2003,and one breeding colony of Great Frigatebirds (Fregata minor) was found on Dong (East) island of Xisha archipelago,which is the first breeding record of this bird so far reported in China.Seven nests,13 juveniles and 2 non-breeders (adult male) were found in the wild.Among 7 nests,5 nests were damaged during the nesting period.Also some behaviors with negative effect were observed between Great Frigatebird and Redfooted Booby (Sula sula) such as robbing of food and stealing nest material.Our investigations showed that the population size and the distribution area of the Great Frigatebird had been decreased remarkably.