Cut feather containing rachis as a sampling way for avian sexing

Sex determination of birds is important to ensure successful breeding strategies, especially for endangered species. Most birds are vulnerable to stress during handling, however, so obtaining a sufficient amount of genomic DNA (gDNA) while causing the least amount of harm is a critical issue. Avian gender can be determined based on different CHD1 gene intron sizes in W and Z sex chromosomes. We have compared various specimen sources and have found that the rachis segment of a feather is a good DNA source for determining sex. This indicates that plucking the whole feather is not necessary; a cut feather including the rachis is a superior method because it decreases stress on the examined birds and is accomplished easily.