Geographic Range: The Pickerel frog ranges from the Canadian Maritime Provinces south to the Carolinas and then west to southeast Minnesota and eastern Texas. However, there are many gaps in the distribution of these frogs, especially in the southern parts of Ohio, Illinois, and Indiana.

Habitat: Pickerel frogs commonly inhabit cool, wooded streams, seeps and springs although they are also found in many other habitats. In the South, it can also be found in the relatively warm, turbid waters of the Coastal Plain and floodplain swamps. These frogs tend to wander far into grassy fields or into weed-covered areas in the summer.

Physical Description: The Pickerel frog is a relatively large frog that is often confused with the Northern Leopard Frog (Rana pipiens). However, the Pickerel frog has chocolate-brown spots arranged in two rows between the dorsolateral folds while the Leopard frog's spots are more irregular and scattered. They can be distinguished by the bright yellow or yellow-orange color on the inside concealed surface of the thigh. Leopard frogs are white in the same area. These frogs range in size from 45 to 75 millimeters as adults. Females are usually larger than males. Male Pickerel frogs have paired vocal sacs, stout forearms and swollen thumbs. These frogs produce toxic skin secretions that are irritating to humans but can be fatal to other small animals, especially other amphibians. Many frog-eating snakes avoid these frogs for this reason.

Diet: These frogs are carnivorous and their diet consists mostly of small insects and other invertebrates. However, as tadpoles, these frogs are herbivorous.

Reproduction: Pickerel frogs breed in late March to early May. Males have low, snore-like calls to attract females.

Eggs: After fertilization, females lay spherical egg masses attached to tree branches in permanent or temporary ponds. These masses may contain from 700 to 3000 eggs. Each egg has an average diameter of 1.6 millimeters when laid. After the eggs hatch, it takes around 87 to 95 days for the tadpoles to transform into small frogs and leave the water. It requires an additional two years before these frogs reach sexual maturity and are able to reproduce.

The Pickerel Frog is a Facultative Species and may be found in vernal pools, but can reproduce in other aquatic habitats where they are available.

Natural History: Pickerel frogs are nocturnal and rouse from hibernation in early spring. These frogs remain active until the end of October when they burrow into sediments in the bottom of ponds or streams and hibernate for the winter.

Vernal Pool Conservation

What you can do:

• Resist the temptation to clean up in and around vernal pool habitats. Leave trees, bushes, and understory vegetation, as well as brush, logs, and dead trees.
• Leave a buffer of natural vegetation around the pool for as great a distance as possible back from the edge of the pool's high-water mark. A buffer of at least 100 feet will help maintain water quality, but will do little to protect amphibians living around the pool. Vernal pool breeders require at least 300 yards of natural habitat around their pools in order to survive.
• Do not fill in the pool, even when it is dry, by dumping leaves or other debris in it.
• In areas with more than one pool, try to maintain travel corridors of natural vegetation between them. If some clearing is necessary, avoid drastic alterations that remove most of the trees and other cover. If habitat alterations are necessary, conduct these activities between November and March, when amphibians are less likely to be present. Activities done when the ground is frozen will cause much less damage to the soil than those conducted during warmer months.
• Avoid activities that inadvertently alter the movement of surface water (hydrology) of the upland area that drains into the pool. Digging ditches and similar activities can change runoff into the pool, thereby altering its flooding cycle.
• Do not dig into the bottom of the pool, even when it is dry, as this will disturb the non-permeable layer of soil that allows the pool to flood.
• Work with local conservation commissions and other interested individuals to identify and document vernal pools in your area.

  *Adapted from the Audubon Society of New Hampshire and the Nongame and Endangered Wildlife Program of the New Hampshire Fish and Game Department.

Photo by Tom Lautzenheiser.

A vernal pool is a temporary or semi-permanent body of water, typically filled in the spring by snow melt and spring rain, and holding water for two or three months in the spring and summer.

Vernal pools form in contained basin depressions, meaning that while they may have an inlet, they have no permanent outlet forming a downstream connection to other aquatic systems. They are typically small, rarely exceeding 50 m in width, and are usually shallow. While most are filled with meltwater and spring rains, others may be filled during the fall or with a combination of seasonal surface runoff and intersection with seasonally high groundwater tables. Typical substrates are formed primarily of dense leaf litter. While most vernal pools are found in upland forest, several types have been identified, including floodplain basins, swamp pools and marsh pools.

Periodic drying is a key feature of the ecology of vernal pools. Drying precludes the establishment of permanent fish populations, which would otherwise act as predators on the eggs and larvae of species that live or breed in the pool. While a typical vernal pool is dry during at least part of the year, others may contain some water throughout the year (or for several years), but a combination of shallow water, summer heat, winter freezing, and periodic oxygen depletion prevent the establishment of fish populations.

Terms:

Obligate Species: Species must live or breed in vernal pools.
Facultative Species: Species may be found in vernal pools, but can reproduce in other aquatic habitats where they are available.
Dorsolateral ridge: Lines or folds of skin (usually gold colored) along the upper sides of some frogs in the family Ranidae.
Intercalary cartilage: An extra piece of cartilage in the toes of members of the Hylidae (tree frog) family. It causes the end of the toes to have a “stepped-down” appearance.
Parotoid glands: Large skin glands that appear as swellings on each side of the back of the head of toads (family Bufonidae) and some salamanders.
Tympanum: This is the external ear drum visible on the side of the head of most frogs.

Arnold, K. 2000. "Rana palustris" (On-line), Animal Diversity Web
Accessed March 30, 2004 at https://animaldiversity.ummz.umich.edu/site/accounts/information/Rana_palustris.html

The Roger Tory Peterson Institute is a national, non-profit nature education organization with headquarters in Jamestown, New York, birthplace of world renowned artist and naturalist, Roger Tory Peterson (1908-1996). In collaboration with the Center for Applied Technologies in Education, the Roger Tory Peterson Institute has provided these animal profiles to offer a glimpse into the diversity of Vernal Pools in our region.