Pickerel Frog (Lithobates palustris)

I crouched down by the stream where a frog had jumped in. There it was! Under a leaf, thinking it was completely camouflaged. Silly frog. I placed my left hand a little in front of it in the water and poked one of its legs with my right, causing it to swim into my open palm. I quickly cupped it with both hands and got a secure hold on the legs. Lo and behold: a pickerel frog!

Pickerel frogs (Lithobates palustris) are medium sized frogs found in most of the eastern united states except for large chunks of most of the southern states (practically doesn’t occur in FL) and in large portions of KY, IL, TN, and AK. It’s a very hard range to describe.

Their call sounds like a really low, drawn out snore. Pickerel frogs start calling late January and end early May. They are calling absolutely everywhere on my college campus day and night, but it is more pronounced during the evening and into the night.

L. palustris eats invertebrates such as spiders and insects, but occasionally mollusks as well. They also react to movement. If it moves, it’s food. You might recall the T-rex in the first Jurassic Park movie who reacted to movement when investigating the tour trucks – same thing just less terrifying.

A really fascinating feature of this species is its toxins. One book I have tells me it is poisonous and gives no further details. Another tells me that some people have had pickerel frogs that will kill other frogs it is bagged with due to the toxins, while others have not had any problem. Its toxicity is not well studied. We do not know if L. palustris has toxins in only parts of its range or if it’s due to diet or if it only occurs during certain parts of its life cycle. We just don’t know. We also don’t know much about their behavior and life history. Do they establish territories? How long do they live in the wild? These frogs should be studied more – especially their toxins.

Lo and behold: a pickerel frog. Photographed by Matthew Anthony.
Lo and behold: a pickerel frog. Photographed by Matthew Anthony.

Thank you for reading! Please check out my other posts if you enjoyed this one!

I used “Frogs & Toads of the Southeast” by Mike Dorcas and Whit Gibbons and “A Guide to the Frogs and Toads of Virginia” published by the Virginia Department of Game and Inland Fisheries. To hear their call, please follow this link.

Gray Treefrog (Hyla versicolor, Hyla chrysoscelis)

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The gray treefrog is a commonly spotted frog in eastern North America. There are two species of gray treefrog: the Cope’s gray treefrog (Hyla chrysoscelis) and the eastern gray treefrog (Hyla versicolor). The two species appear identical, but can be distinguished by their calls or by quantifying their chromosomes (H. versicolor has twice the number of chromosomes as H. chrysoscelis). Gray treefrogs range in color, from green to gray to brown. They can be solid in color, or exhibit blotchy skin patterns to aid in camouflage with their surroundings. They are also able to change their color within seconds. All individuals have a small white spot beneath the eyes, and large toe pads for adhering to trees and foliage. Gray treefrogs have bright patches of yellow or orange along the insides of their hind legs that they flash as an anti-predatory mechanism. Whether these “flash colors” serve to startle potential predators or to falsely indicate the presence of toxins is unknown. These frogs are also known to utilize death feigning when captured or handled.

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Diet/Feeding: Gray treefrogs consume a variety of terrestrial and arboreal invertebrates, including earthworms, flies, beetles, roaches, crickets, and caterpillars. Although they are considered a sit-and-wait predator, they have frequently been observed to jump between branches to catch a prey item.
Habitat/Range: The collective range of both species of treefrog can be found all throughout the eastern United States, beginning in Texas and extending north to the Great Lakes. As their name suggests, treefrogs are primarily arboreal frogs. They typically inhabit deciduous forests and swamplands that are near to aquatic habitats for breeding.
Reproduction: The breeding season for these frogs begins in April and lasts until August. Males migrate to trees and other plants near ponds and swamps, where they begin their mating calls to attract females. Both sexes typically mate up to three times per mating season. The female deposits 30-40 packets of up to 60 eggs each on vegetation that is close to the surface. She can lay up to 2,000 eggs in a single breeding season. The eggs generally hatch in three weeks and the tadpoles remain in their aquatic environments until they metamorphose four weeks later.
Herping Tips: Gray tree frogs are nocturnal and spend most of the day resting in trees. Look closely, they are able to blend in with their environments to avoid predation.
Fun Fact: Gray tree frogs are one of only a few freeze-tolerant frog species, to a temperature of -7.2°C. They can freeze by accumulating glycerol in their muscles, which is then converted to glucose and circulated through the cells. The remaining liquids in the frog’s body freeze until winter is over and the frog thaws, recovering over 33% of its frozen water for use by the body.