A Molecular Analysis Of The Ostrich (struthio Camelus Massaicus) Primary Sex Ratio.

Abstract

The genetic sex in many species of birds cannot be determined by morphology at hatching. Sex identification at the DNA level is now widely used. We used a W-linked sex-specific DNA marker in the ostrich Struthio camelus massaicus to characterise the sex of embryos from different nests at Nairobi National Park. A slight female biased primary sex ratio of 1:1.35 was found. This primary sex ratio was not significantly different from a 1:1 equality. This finding is consistent with observed ostrich secondary adult sex ratio. The ostrich therefore seems unlikely to experience differential sex mortality in their life history despite the adults being sexually dimorphic and exhibiting male-male competition.