Since 1989, an increasing number of scientists have been studying the decline of frog and toad populations around the world. These declines have been associated with habitat loss and fragmentation, chemical pollution, ultraviolet radiation, acid precipitation, commercial harvest for food, and unknown causes. Understanding frogs may help us better understand how these problems affect humans, too. Learning about frogs is also fun and, as this page shows, opens a door to a facinating corner of the natural world.
adapted by Cindy Reinitz from J. Gerholdt,
This is a familiar species, often called a "grass frog." It is found in all Minnesota counties. This large frog averages from 2 to 3 1/2 inches (5-9 cm.) in length, through the record is 4 3/8 inches. The basic color is green or brown and there are usually two or three rows of dark spots on the back, some large and some small. The Northern Leopard also may have no spots at all or, less commonly, extra dark markings between the rows of spots. It lives in a wide variety of habitats, but is usually found in meadows and open fields near bodies of water.
This is one of the earliest and most common frogs in the state, though it is commonly more easily heard than seen. It is only 1 1/4 inches (3.2 cm.) from tip to tail and easily recognized by its pear-shaped body. The head is pointed, the body slender, and the rear of the body larger than the rest. It's basic color is tan, red, green, or gray and there are three long dark stripes on the back. It is found in moist, fish-free habitats all over Minnesota.
This frog measures from 2 3/8 to 3 1/2 inches (6-9 cm.) long, but can grow as large as 4 1/4 inches. The basic body color is green to brown. Look for an upper lip that is lighter and brighter green than the head. This frog is easy to confuse with the mink frog, which appears later in the season. The green frog is found over the eastern half of the state in rivers, streams, lakes, ponds, and wetlands with permanent water and emergent vegetation.
This frog is very tiny, with a body length of only 3/4 to 1 1/4 inches (1.9-3.2 cm.). The body color may be tan or dark brown, or even gray and has a darker "X" marking across the back. Even though they are small, it's easy to see the toe pads on the peeper. These are the adhesive pads that enable the frog to climb smooth, vertical objects. The spring peeper is confined to the woodlands of eastern and northwestern Minnesota.
The song is a high-pitched note, a peeping sound. A single frog calling
sounds like a shrill whistle, but a group calling together sounds very
much like sleigh bells.
The mink frog measures 2 to 2 3/4 inches (5-7 cm.) in length. The basic body color is green with dark mottling. The mink gets its name because it smells much like its namesake. This species is found in the northern half of Minnesota in forested areas with ponds, lakes, and slow-moving streams. You will often see this frog sitting on lily pads.
CALL: The song is a "knock-knock" sound , and the males call
while floating in the water.
This tiny frog measures only 5/8 to 1 1/2 inches (2-3.8 cm.). The basic body color is brown to gray, with odd-sized green blotches. Look for a green or dark brown triangle between the eyes. Though this species has been recorded from both the southeastern and southwestern corners of Minnesota, it may be gone from our state. Look for this frog along muddy shorelines beside slow streams or ponds with lots of emergent vegetation.
CAll: The song sounds much like that of a cricket. It can be confused
with the call of the Virginia rail.
The bullfrog is the largest anuran, measuring up to 8 inches (20.3 cm.). The basic body color is varying shades of green, and is sometimes mottled with green or brown. This frog is native to the extreme southeastern counties of the state but has been introduced in other areas. Permanent bodies of water are necessary for this species, and may include lakes, rivers, and ponds.
Another early spring frog, the wood frog measures from 2 to 2 3/4 inches (5-7 cm.) long. The presence of a "robber's mask" makes this an easy species to identify. The body color is generally light tan to dark brown, with a series of darker brown lines along the dorsolateral folds (the raised bumps between the eyes and the hind legs). Found in most of Minnesota except the southwest corner, wood frogs prefer woods and forests and require marshes and small ponds for breeding.
This frog measures 1 3/4 to 3 1/4 inches (4.5-8 cm.) long. The basic body color is tan with two rows of dark brown square-shaped spots on the back. The groin area is bright yellow or orange. The secretions of the pickerel's skin is toxic. This frog is found only in the southeastern corner of Minnesota and has only been recorded in five counties. Its habitat is the edges of small ponds, medium-sized rivers, and spring-fed streams.
CALL: The pickerel sings while submerged under water, so its song is
difficult to hear. The song is a low-pitched snoring sound.
Tree and Cope's Gray Tree Frog
Both species are small, measuring only 1 1/4 to 2 inches (3-5 cm.), and are variable in color. They may be gray or green, depending on temperature or location. In warm conditions when they are on vegetation, the frogs are green. Both may have large gray blotches on the back. The gray tree frogs are bordered with black. The skin texture is different in the two species. The cope's is smooth and the gray's rough. Both have large toe pads and are excellent climbers. The gray tree frog is found in woodlands all over Minnesota except in the southwestern corner, while the cope's gray tree frog inhabits prairie edges and oak savannas in the central third of the state.
The cope's song is like a fast metallic trill, while the gray's is more
melodic and slower. You can tell which species is calling by determining
its height off the ground. If the frog is calling from 10 feet or higher,
it is a gray tree frog; less than that height would be a cope's gray tree
This is one of the most common toads in Minnesota. It measures from 2 to 3 1/2 inches (5-9 cm.) long and has a squat body and short legs. The basic body color is usually brown but may be red or even greenish. There are white and black blotches all over its back, with one or two warts in each of these. This toad is found all over Minnesota in prairies, woods, coniferous forests, bogs, and even in gardens.
This toad (not pictured) measures from 2 to 3 1/2 inches (5-9 cm.), with a grayish brown to green body color and large dark spots that are edged in white. This distinguishes it from the American and Canadian toads. This prairie species is found in the western counties of Minnesota.
CALL: The song is a harsh matallic sound, not musical like other toads.
This toad (not pictured) measures from 2 to 3 1/2 inches (5-9 cm.), with a squat body and short legs. The basic color is brown with white and black markings. There is a distinct raised bump between the eyes, and this will enable you to distinguish it from other species. This toad is confined to the northwestern corner of Minnesota, and uses a wide variety of habitats.
CALL: The song is similar to that of an American Toad, but the length of the trill is shorter.
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