Don’t know the green frog? Picture a smaller version of the bullfrog. The two species look almost identical, but the green frog has two obvious ridges down either side of its back, called “dorsolateral folds.” Also, bullfrogs tend to stick to large, marshy bays; green frogs prefer slow rivers and quiet ponds.
Scientists suspect the two frogs are so similar because they both evolved from the same amphibian line, and only recently split into two different species. (Recently in terms of evolutionary timelines, at least.) In rare circumstances, a green frog will even mate with a bullfrog.
Green frogs spend the winter in muddy streams, below the ice; they emerge as early as April, when the ice on the surface of the water starts to melt, and the air temperature reaches 10°C. When the days warm up in June, the frog’s long breeding season—it lasts into August—begins, along with their love songs. A male green frog produces several variations of a deep, repeated “gunk” sound—a little like the twang of a banjo. Aww. What lady frog wouldn’t want to be serenaded by banjo?
Even though the calling begins in June, and males start to stake out their territories, females aren’t really part of the equation until the beginning of July. This is when they’ll start looking for suitable egg-laying spots: ideally, warm, shallow water and vegetation cover (this hides their babies from predators). Once a male and female hook up—and are occupied with the business of mating—a sneaky, less-dominant male might move into the now-empty calling “perch” in hopes of snagging another female frog that was already drawn to the old host’s breeding territory. Well played, frog.
It only takes a few days for green frog eggs to hatch (the warm summer water speeds the process along). By the following summer, the tadpoles have transformed into frogs. Yay, now they have legs! Which means they can immediately hop on land, and start looking for a new water body to call home.