A banjo and a jug

Let’s stick with our aquatic theme of recent weeks and get to know two amphibian inhabitants of our lakes and ponds: the

green frog and the American bullfrog .

We’ll start with the largest species in Connecticut, the bullfrog, which can measure up to 8 inches long. In coloration, it is usually greenish, sometimes brown, and can be confused with the smaller green frog, especially if not full-grown.

What the bullfrog lacks is a line or ridge running down its back on each side, from behind the circular "ear" (technically, the tympanum) to its hindquarters. The absence of this line gives the bullfrog a markedly different shape from the green frog, and is useful for separating the two species.

Bullfrogs are omnivorous predators, known to take small birds, many types of insects, small crustaceans, and frogs smaller than themselves. In breeding season, they lay thousands of eggs that float on the surface of the water. The ones that survive to become tadpoles take up to three full years to reach maturity and transform into frogs.

The unmistakeable call of the bullfrog is the deep, throbbing sound often written out as "jug-o-rum" and so characteristic of swamplands, particularly in the South.

The green frog averages half the size of a bullfrog, about 3 to 4 inches in length. Its coloration is most often bright green, but it can vary. As mentioned previously, it can be identified by the dorsal ridges. Its diet is similar to that of the bullfrog, excluding the larger prey items.

Green frog eggs are laid in water and take one or two years to mature into full-grown frogs. As for its call, the green frog has an equally distinctive one that sounds like the plucking of a banjo string.

Both the green frog and American bullfrog are common throughout our region. In winter, they will hibernate underwater and emerge again in spring.

A reminder:

Next weekend, Aug. 9 and 10, is the Sharon Audubon Festival. I hope to see you there!

Fred Baumgarten is a naturalist and writer. He can be reached at fredb58@sbcglobal.net. His blog is at thatbirdblog.blogspot.com.