A new study has shown that mercury pollution can affect sexual preference in some species of birds and could make males more likely to mate with other males.

The study at the University of Florida, which went on for a year, shows that white ibises hormones could be altered and make males behave homosexually.

Peter Frederick, a wildlife ecology and conservation professor who led the study along with his co-author Nilmini Jayasena from the University of Peradeniya in Sri Lanka found white ibises that consumed methylmercury were more likely to mate with other males while homosexual tendencies are non-existent in wild ibis birds that do not come in contact with mercury.

"We knew that mercury can disrupt hormones -- what is most disturbing about this study is the low levels of mercury at which we saw effects on hormones and mating behavior. This suggests that wildlife may be commonly affected," said, Frederick.

He also expressed that birds that live in wetlands are most venerable because such conditions are breeding ground for bacteria that convert the mercury from coal plants into methylmercury. The Mercury becomes methylated when it come sin contact with bacteria that use sulfur for metabolism. This process is common is wetland areas, according to Frederick.

The two researchers studied 160 white ibis nestlings over a three-year period. And found that males with higher levels of mercury were less likely to be approached by a female and more likely to display homosexual orientation. As the level of mercury exposure increased, the degree of homosexual paring also increased.

The study was published online in the Proceedings of the Royal Society B on Wednesday.