Sex identification of the ashy-throated parrotbill (Paradoxornis alphonsianus): A species heavily hunted for bird fighting in Guizhou Province, China

The ashy-throated parrotbill (Paradoxornis alphonsianus) is a sexually monomorphic species with high abundance in Southwest China, which has been widely used as a fighting bird across Guizhou Province, leading it to become one of the most coveted and heavily hunted wild birds in the region at present. Information on the sexes is a fundamental requirement for a wide variety of avian studies. From a conservation perspective, knowledge necessary for quick sexing of this species should be important, as the determination of sex contributes to the understanding of which sexes are used for fighting. Our goal was to develop a quick method that can be used to identify sex of the ashy-throated parrotbill in the field. Seven body traits were measured and compared between the sexes among 124 individual ashy-throated parrotbills, with sex determined by molecular techniques. Data revealed that the male is the larger sex, with significantly greater measurements than the female in bill length, wing length, and middle claw length. The univariate discriminant function based on bill length featured the highest identification accuracy (67.7%). The larger body size of males may have evolved by sexual selection, but additional data are needed to test this hypothesis. This study found that male and female ashy-throated parrotbills are divergent in size, although further efforts are required for a discriminant function with more robust accuracy.