Highly skewed sex ratios in the critically endangered Taita thrush as revealed by CHD genes

The study of sex-ratio patterns in threatened bird species has yielded crucial information with regard to their conservation and management. In the case of sexually monomorphic species, i.e. species that cannot be sexed by their appearance, DNA-based sexing techniques are increasingly applied. We present data on the sexing of adult Taita thrushes, a critically endangered forest endemic from south-east Kenya. In addition to describing a morphometric trait that can be used to sex individuals directly upon capture, we comment on a remarkable skew in sex ratio that might have important consequences for the long-term survival of the species.