Researchers in a recently conducted study have found that frogs living in or near suburban areas are turning into females. The study carried out by a team of researchers from the Yale University has been published in the Proceedings of the National Academy of Sciences.

According to Newsweek, the study researchers found that both urbanization and estrogenic wastes are the causes responsible for altering the gender of these amphibians.

As per the study researchers, higher levels of estrogen in the water can disrupt the animal’s endocrine system, and once this disruption occurs, it affects the frog’s sexual development.

The researchers analyzed several hundreds of young frogs from 21 different ponds in Connecticut. All the ponds were geographically close, but the surroundings of each pond greatly varied.

The team found that ponds located near suburban areas tended to have higher female green frogs as compared to other ponds that were located near forest areas.

Earlier conducted studied have shown that these gender chances can be caused by pesticides or chemicals. But findings of the latest study have cleared that estrogenic chemicals in suburban locales are disrupting frogs’ endocrine systems.

Lead author Max Lambert, a doctoral student at the Yale School of Forestry & Environmental Studies, said, “In suburban ponds, the proportion of females born was almost twice that of frog populations in forested ponds. The fact that we saw such clear evidence was astonishing”.

The team did not try to locate the source of estrogen in the water, but some previous findings have shown that agricultural runoff and water contamination near farms also have changed hormone regulation in frogs.