Amphibians and Reptiles of Minnesota

A Complete On-line Field Guide to Minnesota's Amphibians and Reptiles

Pickerel Frog - Lithobates palustris PDF Print E-mail
Frogs, Toads and Treefrogs of Minnesota - Frogs, Toads and Treefrogs of Minnesota




 
Pickerel frogs calling in Houston County, MN


by Jeff LeClere

Pickerel frog, Rana palustris, from Winona County, MN

 

 

 

 

 

 

 

 

Status

Listed as a Species in Greatest Conservation Need in Minnesota.

Description

The pickerel frog is a medium sized frog being about 3 inches in body length. Adults are tan or brown (never green) with four to five pairs of squarish brown spots. They have complete light gold dorsolateral ridges down the back. The belly is plain white. There is a distinctive yellowish wash in the groin areas and the thighs. There are brown "tiger stripes" on the hind legs. The pickerel frog could be confused with the very similar leopard frog. Unlike leopard frogs, pickerel frogs are always brown (leopard frogs may be green or brown), have square spots arranged in pairs on the back, a yellowish wash on the thighs (leopard frogs usually have a greenish wash), and a restricted Minnesota range.

Subspecies

There are no subspecies of the pickerel frog, Lithobates palustris. This species was formerly placed in the genus Rana.


Range

The pickerel frog has been recorded in only six counties in southeastern Minnesota.

Habitat

Pickerel frogs are found most commonly in rivers or clear water trout streams. They may be found in small ponds or wetlands, but usually these are near rivers or streams. They breed in ponds and pools adjacent or connected to streams and rivers.

Habits

Pickerel frogs breed in spring (late April, May, and June). The male's call is a deep snore. It is shorter and higher pitched than the leopard frogs' call and is usually not followed by a "chuckle" as in leopard frogs. They call from the shore or from underwater in shallow portions of the wetland. Females lay 2,000 to 3,000 eggs. The tadpoles transform in two or three months. Pickerel frogs usually stay close to the water. Few move into wet habitats. I have seen pickerel frogs away from streams in damp, forested uplands in Winona and Houston counties. These are usually large adults that will not dehydrate as quickly as smaller specimens. They hibernate in streams or rivers or may migrate to shallow ponds, if close. Pickerel frogs produce toxic skin secretions that are distasteful and harmful to predators. The toxin is fatal if it is absorbed through the skin as other frogs (even other pickerel frogs) have been killed when they are placed in a small container with pickerel frogs.

Food

Pickerel frogs consume insects, earthworms, and other invertebrates.

 
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