When two birds become too many. This blog is about failed eggbortions, unplanned hatching, and the lives of a brooklyn parrotlet family.
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All Drawings and Illustrations © Niko Economidis 2010
Sex Determination in Birds

In mammals the female is XX and the male is XY, this results in the male sperm determining the sex of the offspring. In birds it is the opposite. The female is WZ and the male is ZZ. All avian sperm is Z, and the female releases either a Z egg or W egg. Therefore it is the female bird that determines what sex her offspring will be.














