Scientists in Australia have discovered an unusual natural phenomenon — some wild birds are switching sex after birth.
A new study by researchers at the University of the Sunshine Coast found that about 6% of birds from five common species had sex chromosomes that didn’t match their reproductive organs. In simple terms, these birds were born as one sex but developed into another.
The research focused on nearly 500 birds, including kookaburras, magpies, and lorikeets.
“This shows that sex in wild birds can be more flexible than we previously thought,” said Dr. Dominique Potvin, one of the scientists behind the study.
Most of the birds that changed sex were genetically female but developed male organs. In one rare case, a genetically male kookaburra was found producing eggs — showing clear signs of female reproduction.
While sex reversal is well-known in some reptiles and fish, it is extremely rare in wild birds and mammals.
Scientists believe that environmental factors may be responsible. These could include, Pollution, Hormone-disrupting chemicals and Rising temperatures.
These same triggers have been linked to sex reversal in other animals like frogs.
The exact cause in birds remains unclear, but researchers say it’s crucial to understand it, especially as environmental stress increases globally.
“Understanding how and why this happens helps us with wildlife conservation and makes our research on bird populations more accurate,” Dr. Potvin added.
This discovery could change how scientists study bird populations, especially when tracking the balance between male and female birds in the wild. If sex is not fixed, long-term bird studies may need to change their methods.
The full study was published in the respected science journal Biology Letters.
