Rare sex reversal phenomenon found in Australian birds and it is more common than believed

Australian Birds Show Surprising and Widespread Sex Reversal (Image: Canva)

A recent Australian study has found sex reversal in wild birds is more common than anyone had realized, catching scientists by surprise and posing conservation issues. The find followed scientists studying almost 500 of five everyday bird species, such as magpies, kookaburras, lorikeets and pigeons.

DNA and Body Features Tell Different Stories
The team led by the University of the Sunshine Coast discovered as much as 6% of birds possessed the genetic structure of one gender but the physical characteristics of another. Most of these were genetically female birds with male reproductive organs, but the study also documented a rare case of a genetically male kookaburra producing eggs.

Birds in the study were examined after being brought to wildlife hospitals in southeast Queensland with unrelated injuries or illnesses. Researchers assessed reproductive organs and conducted DNA tests to compare genetic and physical sex.

Conservation and Research Implications
Lead author Dr. Clancy Hall said the presence of sex-reversed birds could alter breeding patterns, skew sex ratios and affect population stability, especially in threatened species. The findings also raise doubts about the reliability of current sex identification methods in bird research.

Associate Professor Dominique Potvin said environmental factors like endocrine-disrupting chemicals or high stress hormone levels could influence sex development in birds. The team pointed to the egg-producing male kookaburra found in an agricultural zone as a possible example.

More research is required, say the researchers, to determine the causes and effects of this as yet poorly documented phenomenon in wild birds.