SYDNEY, Aug. 13 (Xinhua) — An Australian study has revealed that sex reversal in wild birds is more common than previously thought, raising conservation concerns.
Researchers found up to six percent of nearly 500 birds from five species studied had the physical features of one sex but the genetic makeup of the other, according to a statement released Tuesday by Australia’s University of the Sunshine Coast (UniSC).
The research, involved five species including magpies, kookaburras, pigeons, and lorikeets, found that 92 percent of sex-reversed birds were genetically female but had male reproductive organs.
They also discovered a genetically male kookaburra who was reproductively active, producing eggs, said UniSC Associate Professor Dominique Potvin.
“This indicates that sex determination in wild birds is more fluid than we thought and can persist into adulthood,” said Potvin, who co-authored the study published in the online journal Biology Letters.
The study on sex reversal, previously known in fish, amphibians, and reptiles, provides a baseline for understanding the phenomenon in Australia’s avian populations, said the authors.
“This can lead to skewed sex ratios, reduced population sizes, altered mate preferences, and even population decline,” said Clancy Hall, the study’s co-lead author from UniSC.
The finding also challenges traditional methods of identifying bird sex, such as genetic markers, plumage, or behavior, according to Hall.
Researchers said chemicals and stress hormones may influence bird sex development, citing a reproductively active male kookaburra found in a chemical-prone agricultural area. ■