2018-03-08 / Nature

The Spring Fever Serenading Frogs

By Charles Avenengo

American bullfrog. North America’s largest frog is explosively expanding its range. (Photo by Bob Weaver) American bullfrog. North America’s largest frog is explosively expanding its range. (Photo by Bob Weaver) All night long, they carol like sleigh bells, they quack like barnyard ducks, they twang like banjos, they snore, they trill and like drunken revelers, they boom out “jug-o-rum.” From now until August, they’ll keep it up all night, every night.

These varied calls are the mating songs of Aquidneck Island’s six species of frogs and toads. On the mainland, Rhode Island has an additional three species of frogs that are not found on Aquidneck Island: the pickerel frog, gray tree frog and spadefoot toad.

A princess may be reluctant to kiss a frog, but frogs certainly love to get that kiss from each other. For millions of years, beginning at this time, frogs have been singing their spring nuptial songs.

While the signs of early spring are just registering with us, the wood frogs have been quacking for a few weeks now. They begin calling just as the ice is out. The Norman Bird Sanctuary currently has wood frogs calling from a couple of spots. They will also call by day, and they are the only species that in the warmer months will be found on the leaf litter in wooded areas.

The more familiar spring peepers have also begun their mating songs. Described as sleigh-bell like, their calls can be deafening. Newport has more than 50 sites of calling spring peepers. With so many more wet spaces, Middletown and Portsmouth harbor hundreds of sites with crooning spring peepers.

Both these frog species revolve their breeding cycle around vernal pools, which are temporary spring pools that dry out in the late summer. These pools do not contain fish that would eat their eggs or their young, so the frogs can safely lay eggs and rear the next generation. Some species of salamanders, the frog’s amphibian cousins, also employ vernal pools.

As the peepers and the wood frogs conclude their affairs next month, a new wave of anuran choristers will begin calling. These are the trills of the common American toad and the snoring of the leopard frogs. Gardeners and children will readily recognize the warty toad. Found throughout the island, a good spot to hear trilling toads in Newport is along the railroad tracks near Murphy Field on Van Zandt Avenue.

The presence of leopard frogs on Aquidneck Island is more of an enigma. Their limited range has been along the upper reaches of the Maidford River in Middletown. Slow-moving streams are one of their preferred habitats. Aquidneck Island is the only Narragansett Bay island with leopard frogs. The question is: Did they come to the island on their own or are they holdovers from the last glacier?

May brings out green frogs. Any walk along the banks of the island’s reservoirs, or along just about any edge of sizable fresh water, will eventually flush a green frog leaping to safety, belting out its banjo-like twang call in mid-air. One interesting phenomenon on Aquidneck Island is the presence of the rare blue-morphed green frog. This variation is caused by the lack of yellow pigmentation. Normally, mixing blue and yellow produces green, but without the yellow pigmentation the result is the blue-morphed green frog.

And then there is the bull frog. Largest of all the frogs, they too begin lurching out their characteristic booming jug-o-rum calls in May. In recent years, the bull frog population has exploded on the island. A good place to hear them is along the northern bank of Easton’s Pond.

The clutch of a female is estimated at 20,000 eggs, and because adult bull frogs are cannibalistic, younger ones emigrate far and wide from their hungry elders to colonize new areas. The problem is that bull frogs eat everything around, and biologists are afraid this population explosion will affect other existing animals in wet areas.

So, get out there and listen to these fascinating amphibian serenades before the bull frogs ruin the party and eat everything in sight.

Recipe for Frog’s Legs

One suggestion for bull frog control has been to eat them.

Amphibians are protected by law in Rhode Island, except for green frogs and bull frogs, which may be taken in the Ocean State. According to the Rhode Island Department of Environmental Management, the importation or possession of bull frogs is prohibited, except for flesh that is cooked or frozen and intended for human consumption.

Here is a recipe for simple sautéed frog’s legs.

Frog’s legs
Milk (as needed)
Salt and pepper
Flour (as needed)
5-6 Tbsp. butter
(or more, if needed)

Soak frog legs in milk for one hour, turning every 15 minutes. Remove from milk and salt and pepper them lightly, then coat them in flour. In a skillet, bring the butter to a sizzle and add frog legs. Sauté legs uncovered until they’re golden brown on both sides (turning as needed).

Naturalist Charles Avenengo has been chasing Aquidneck Island wildlife for more than 40 years.

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