Frogs are a familiar part of the wildlife of Massachusetts, and they’re found all across the state. Because of their diverse habitat needs and sensitive skin, these amphibians are good indicators of the health of our environment. There are 10 frog species in the Commonwealth, and one, the eastern spadefoot, is listed as Threatened under the state’s endangered species act.
Frogs tend to have bulging eyes and long back legs that help them hop, climb, or swim. They’re amphibians, so they rely on their environment to warm or cool them, and tend to lay their eggs in water.
All frogs belong to the order Anura, which means “no tail” in Latin. Toads are frogs; people have used the term toad for various unrelated species and groups of frogs. One group, the true toad family Bufonidae, has members that can be distinguished by large poison glands behind their eyes, shorter legs, and dry, typically warty skin.
Frogs can be surprisingly vocal. They make calls for a variety of reasons, including attracting mates, telling competitors to back off, and expressing alarm. The calls are valuable identification clues.
Many creatures eat frogs, including herons, northern water snakes, minks, raccoons, and more. Frogs use several strategies to avoid predators. They may leap away, produce distasteful or even poisonous chemicals, hide underground, and/or or use camouflage colors.
Frogs generally breed in wetlands. Their mating behavior, called amplexus, involves the male grasping the female and fertilizing her eggs as she releases them. The jelly-like eggs are deposited singly or in masses on underwater plant material or in free-floating films.
When the young hatch, they are tadpoles, breathing through gills and swimming with the help of a flattened tail. Over time they develop legs, lose their tail, and breathe air.
Most tadpoles eat aquatic plants and detritus, but some consume animal prey such as small fish. Adult frogs are important predators of insects. Large frogs may eat other small animals such as mammals, amphibians, and fish.
The frogs of Massachusetts come in many colors, and they inhabit a variety of habitats, from lakes to trees to woodlands. The 10 species in Massachusetts belong to four scientific families. Five species, including the familiar American bullfrog, belong to the family Ranidae, the true frogs. Two species are members of the true toad family Bufonidae. Two belong to the family Hylidae, the tree frogs and allies. One frog is a member of the Scaphiopodidae family of American spadefoot toads.
Types of Frogs in Massachusetts
American Bullfrog (Lithobates catesbeianus)
This is our largest frog. It has a green face and a green-brown body. A ridge of skin runs from its eye curving around its external eardrum (tympanum). Found statewide, it inhabits permanent bodies of water such as ponds and marshes, and eats almost anything it can grab. You can hear its deep “jug-a-rum” call in late spring and summer. It lays its eggs as a film on the water’s surface.
American Toad (Anaxyrus americanus)
A member of the true toad family Bufonidae, this common species can range from pale olive to tan to brick red to almost black, with large warts often surrounded by black spots. It can often be found on the forest floor, eating small creatures such as slugs and worms. Its long trilling call is heard in spring and summer. In spring or early summer. it drapes its long lays long, spiraling strings of eggs over submerged vegetation. It's found across the state, except on Nantucket and Martha's Vineyard.
Eastern Spadefoot (Scaphiopus holbrookii)
This brownish animal is often called a spadefoot toad, though it’s not related to the true toads. It has yellow stripes, small warts, and catlike pupils. The term spadefoot comes from the hard digging structures on its hind feet. Rarely seen, it spends much of its time underground or hunting for small prey at night. After a strong rainfall event during the warm months, it breeds in shallow temporary pools. It’s mostly found in the Connecticut River Valley and on Cape Cod. Learn more about our work with spadefoot toads
Status: Threatened in Massachusetts, and under the Massachusetts Endangered Species Act it is illegal to kill, harass, or possess this animal.
Fowler's Toad (Anaxyrus fowleri)
Another so-called true toad, this species looks a lot like the American toad. However, it has clusters of three or more small warts enclosed by dark splotches, a mostly spotless belly, and paratoid glands that meet at the back of the eyes. It’s found in sandy areas near wetlands, and the female lays long strings of eggs in permanent water. Listen for the high-pitched “wahhh” call in spring and summer. It lives throughout the state except on Nantucket and Berkshire County.
Gray Treefrog (Hyla versicolor)
A master of camouflage, this gray-brown frog blends in with the tree bark on which it perches. Its call, heard from spring through summer, is a short, high-pitched trill. It lays loose masses of 30-40 eggs along the shores of ponds. Young frogs are bright green. Find it everywhere but Dukes and Nantucket Counties.
Green Frog (Lithobates clamitans)
This is one of our most familiar frogs and is found statewide. It can range from dark brown to bright green, with a ridge running down each of its sides. This species prefers permanent or semi-permanent water bodies, eating whatever it can grab, from insects to snakes to birds. The call is a banjo-like “gunk,” and the female lays a thousand or more eggs at a time as a film on the water’s surface.
Northern Leopard Frog (Lithobates pipiens)
Named for its pattern, this vibrant frog has dark spots outlined in a lighter color. It relies on a diversity of habitats, breeding in marshes and floodplains, hunting in fields, and wintering in permanent water bodies. In spring it makes a rattling, grunting call and lays dark masses of eggs. Look for this frog statewide except for Barnstable, Dukes, and Nantucket Counties.
Pickerel Frog (Lithobates palustris)
This species looks much like a leopard frog, but with more parallel angular spots arranged along the back and with bright yellow under its waist and down its thighs. Found statewide, it inhabits ponds, wetlands, and slow-moving streams, breeding in spring and making a snoring call.
Spring Peeper (Pseudacris crucifer)
A small, round frog with a dark mask, it often has a brown cross on its back, which led to the species name crucifer, meaning “cross-bearer”. This frog inhabits wooded areas near wetlands and ponds all across Massachusetts. In the spring it makes a loud, high-pitched peeping call to attract a mate. The eggs are laid singly or in small groups on underwater vegetation.
Wood Frog (Lithobates sylvaticus)
This masked frog looks somewhat like a much larger spring peeper, but look for the ridges running down the sides and no pattern on the back. True to its name, it lives in forests, breeding in temporary, or vernal, pools. It attracts mates with a quacking call, and the female lays fist-sized masses of eggs. Find this species everywhere but in Dukes and Nantucket Counties. Learn more about vernal pools
How Mass Audubon is Helping Frogs
Frog populations all across the world are declining as a result of habitat loss, pollution, and introduced disease. Besides protecting habitat and working to reduce pollution, Mass Audubon is acting to preserve vernal pools, temporary water bodies that some frog species, such as eastern spadefoots, require as nurseries for their young. Read more about vernal pools and learn more about our work with spadefoots.
Reviewed July 2022