Bullish on Wetlands

The eleven species of frogs found in Pennsylvania range smallest to largest from the northern cricket frog (Acris crepitans crepitans) at 35 mm (1 3/8 in.), to the bull frog (Rana catesbeiana) 203 mm (8 1/8 in.). The bull frog is also the largest frog in the northeastern U.S. and one of the largest frogs in North America.

Frogs are known for their vocalizations, which are unique to each species and vary from mechanical sounding clicks to more musical chirps. The hallmark of the bull frog's courtship ritual is a gutteral "jug-'o-rum," ascending towards the ending. Unlike some frog species that primarly sing in the spring and are then silent, the bull frog's song is a signature of warm summer nights.

All of Pennsylvania's frogs require wetlands and waterbodies for their survival. Given the estimated 50% loss of wetlands in the state to date, certainly populations of some frogs have declined. The bull frog is one of the more adaptable species in terms of habitat usage, and any significant permanent body of water is potential habitat, including natural lakes, farm ponds, marshes, swamps, rivers and large creeks.

Although frogs are harmless to humans, they are all carnivores and consume a variety of other animals. In the case of a sizeable adult bull frog, prey items can range as large as other frogs and even small mammals.

The frog pictured today is a female, which can be determined by comparing the size of her eye to the circular tympanum disc (ear) just behind the eye. These are about the same size. The male's tympanum is twice as large.

Today's photo was taken by WPC volunteer John Karian at a pond in Sandycreek Township, Venango County, PA.

Bull frog sound courtesy of the Toronto Zoo.

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