Abstract
Many species of Falconiformes are difficult to sex, since they are monomorphic in external morphology, as are many other avian species. This problem may prevent ecological studies of them and make it difficult to plan conservation programs. Therefore, development of a sexing method for Falconidae has been desirable. We performed sex identification for eight species of raptors that inhabit Japan, using a method based on the difference of intronic length between the CHD1W and CHD1Z genes. This method of sexing is easier and quicker to perform than other methods developed thus far, and made identification possible for all species tested. Moreover, successful sexing from a small DNA source suggests that this method may be applicable to the research of individuals/populations in the wild. In conclusion, the method used in this study is very useful for sex identification in raptors and could be of great value for any future conservation of rare raptors.
