Researchers have documented a surprising rate of sex reversal in wild Australian birds, a phenomenon that may be linked to pollution or other environmental factors.
The study, led by scientists from the University of the Sunshine Coast, examined five common Australian species, including kookaburras, magpies, and lorikeets. DNA tests on nearly 500 birds revealed that about six percent had the chromosomes of one sex but the reproductive organs of another.
“This indicates that sex determination in wild birds is more fluid than we thought, and can persist into adulthood,” said study co-author Dominique Potvin.
Most cases involved genetically female birds developing male gonads. However, the researchers also identified a genetically male kookaburra that was reproductively active, with large follicles and a distended oviduct indicating recent egg production.
While sex reversal is well-documented in some reptiles and fish, it has been considered rare in wild birds and mammals. Previous studies have shown that pollutants and temperature changes can trigger sex reversal in frogs, but the causes in birds remain unclear.
Scientists speculate that environmental factors, such as hormone-disrupting chemicals accumulating in habitats, may play a role.
“Understanding how and why sex reversal occurs is vital for conservation and for improving the accuracy of bird research,” Potvin added.
The study was published this week in the peer-reviewed journal Biology Letters, offering new insights into avian biology and raising questions about the impact of environmental change on wildlife.
Written By Rodney Mbua
