Green lawns and frogs’ sex

Neatly manicured suburban lawns and gardens are playing havoc with the frogs’ endocrine systems, according to a Yale study published in the Proceedings of the National Academy of Sciences.

In 2012, researchers at the School of Forestry & Environmental Studies counted frogs at 21 ponds in southwestern Connecticut and found almost twice the proportion of females being born as in forested ponds. “The fact that we saw such clear evidence was astonishing,” said lead author and doctoral student Max Lambert. Previous studies had found such effects from agricultural pesticides and wastewater effluent, but this is the first to find them in the suburbs as well.

Because some common plants naturally produce phytoestrogens, Lambert said, just maintaining a lawn may be a source of contamination. And other species—wood frogs, gray tree frogs, salamanders, birds, and turtles—may be affected as well.