A new research has made the unexpected observation that suburban male frogs are turning into females due to the high estrogen levels found in vegetable gardens, well-kept laws and others that are treated with various substances or littered with certain types of plants.
Previous studies have uncovered that both climate change and pesticides can have similar effects upon the population, though the researchers at Yale University have noticed that urban areas are not any less effective.
The researchers studied a number of 21 ponds across southwestern Connecticut, and found that the traces of estrogen in the average backyard can affect the frog’s endocrine system, and thus alter the ratio of male to female frogs. They gathered results from both ponds that were heavily surrounded by forests and bodies of water deep within the suburban area to draw an accurate comparison.
The numbers were highly unexpected, as they’ve shown that ponds surrounded by urban areas had twice as many females as those living deeper within the forests. It means that the population is inadvertently contaminating their own lawns while treating it and up keeping its trimmed and pleasant aspect.
According to lead author of the study, Max Lambert from Yale University’s School of Forestry & Environmental Studies, the ponds surrounded by urban areas were similar to those found around farms and sewage treatment plants, which puts it up to question on what exactly are people using on their yards or vegetable gardens.
Whatever it is, it’s apparently leaking into the sewer system and making its way into the suburban ponds, effectively altering the gender of its frog inhabitants.
Due to the unexpected results of their findings, researchers did not reach a conclusion as to what precisely causes this disturbance into the frog’s endocrine system, but it is believed that lawn treatments and ornamental plantings might have something to do with it. Some common plants found in backyards, such as clovers, naturally produce phtoestrogens.
Their findings has bred the belief that more amphibians may be affected by the high levels of estrogen, and perhaps undergoing the same process, such as wood frogs, gray tree frogs, and salamanders. However, others beyond amphibians may be affected as well, ranging from species of birds, to turtles or mammals.
So far, no definitive cause has been found, but researchers are “trying to understand how the suburbs influence sexual development in other species”. It is possible that lawn treatments and naturally occurring plants may be causing the disruption, and making back yards unwittingly a source of contamination of nearby ponds.
Image source: phys.org