Are There Bullfrogs in Maine?
Yes, bullfrogs are found in Maine, though they are more common in the southern parts of the state. These large frogs thrive in ponds and lakes along the coast and inland. Bullfrogs prefer warmer waters and concentrate in suitable habitats. Summer brings peak activity throughout Maine's major pond and lake systems.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated August 6, 2026.
Yes, bullfrogs are found in Maine, though they are more common in the southern parts of the state. These large frogs thrive in ponds and lakes along the coast and inland. Bullfrogs prefer warmer waters and concentrate in suitable habitats. Summer brings peak activity throughout Maine's major pond and lake systems.
Where Bullfrogs Are Found in Maine
Bullfrogs in Maine concentrate primarily in the southern regions, with populations becoming sparser as you move north toward the Canadian border. The coastal areas around Portland and the Casco Bay region support healthy bullfrog populations in freshwater ponds and brackish marshes. Inland, the Belgrade Lakes chain south of Augusta provides ideal bullfrog habitat, as do the ponds scattered throughout Oxford and Cumberland counties. The Sebago Lake area and surrounding wetlands are particularly productive. In central Maine, populations exist but are less abundant than southern areas. You are most likely to encounter bullfrogs near the state's southern border where warmer summer temperatures create better breeding conditions. The northern portions of Maine, including areas around Penobscot Bay and Moosehead Lake, have fewer bullfrogs due to cooler water temperatures and shorter warm seasons. Seethe Bullfrog guide for Mainefor more.
Seasonal Timing and Activity
Bullfrogs in Maine are active from late spring through early fall, with the most intense activity from June through August. They emerge from winter hibernation in shallow pond bottoms as water temperatures rise above 50 degrees Fahrenheit, typically in mid to late May. Males begin calling in late May and June, producing their characteristic deep jug-o-rum vocalizations that echo across wetlands during warm evenings. Breeding peaks in late June and July, when females lay eggs in gelatinous masses attached to aquatic vegetation. Tadpoles develop slowly in Maine's cooler waters, often overwintering before transforming into froglets the following year. By September, as nights cool and water temperature drops, bullfrogs become less active. They gradually settle into deeper areas and eventually burrow into mud for winter dormancy. Peak listening season for their calls is early morning and dusk during July and August. Seethe Maine wildlife guidefor more.
How to Identify a Bullfrog
Bullfrogs are Maine's largest native frog species, measuring four to six inches in body length and sometimes reaching eight inches. Their skin is smooth and green to olive-brown, often with darker blotches or mottling that provides camouflage in aquatic vegetation. The most distinctive feature is their prominent tympanum, a circular eardrum visible behind each eye that appears as a large disk roughly the size of the eye itself. Males typically have a yellow throat, while females have a white or pale throat. The bullfrog's stocky build and powerful hind legs distinguish it from Maine's smaller frog species like leopard frogs and pickerels. Their call is their most recognizable feature, a deep resonant jug-o-rum sound produced by males using their vocal sacs. Juveniles and females are quieter and less conspicuous, but their large size and tympanum still identify them clearly among Maine's native amphibians.
Where Sightings Concentrate in Maine
Bullfrogs concentrate in specific habitat types throughout their Maine range. Shallow bays and coves of lakes, particularly where water temperatures remain warmer, consistently harbor bullfrogs. The marshes around the Saco River and Presumpscot River systems provide excellent bullfrog habitat. Cattail and bulrush marshes in particular attract bullfrogs, as these plants provide shelter and breeding sites. Beaver ponds created across Maine's interior wetlands often support bullfrogs, especially in the southern half of the state. The edges of larger lakes, particularly where emergent vegetation provides cover, are reliable spots. Visitwildlife/maineand explore the state'smajor aquatic habitatsfor more information on where amphibians congregate. Small, isolated ponds with stable water levels throughout summer are hotspots for breeding populations. During the heat of summer, bullfrogs gather in deeper water sections of ponds, while they move to shallower margins at dawn and dusk for feeding.
Bullfrog Behavior and Diet
Bullfrogs are carnivorous ambush predators, spending much of their time sitting motionless at the water's edge or partially submerged among aquatic plants. They wait for prey to approach, then capture it with a powerful tongue strike. Bullfrogs in Maine eat insects, smaller frogs including other bullfrogs, aquatic invertebrates, and occasionally small fish and crawfish. Young bullfrogs as tadpoles feed on algae and aquatic plants, but transform into insectivores as froglets. Adult bullfrogs are highly territorial, with males defending specific calling sites and shallow-water zones. They produce their loud calls to establish territories and attract females. Bullfrogs are primarily nocturnal, becoming most active during warm evenings when feeding and calling occur. They have excellent eyesight for detecting movement and respond to vibrations in the water. In cooler months, bullfrogs become inactive and settle into deep water or burrow into bottom mud, where they enter a hibernation-like state lasting five to seven months.
Coexistence and Legal Notes
Bullfrogs in Maine are fully protected under state wildlife laws and cannot be collected, harmed, or killed without special permits. They play an important ecological role in controlling insect populations and serving as food for herons, snakes, and turtles. Bullfrogs can coexist peacefully with human activities in and around lakes and ponds. However, they are sensitive to water pollution, pesticides, and habitat loss. Acidic water from atmospheric deposition affects egg and tadpole survival in some Maine ponds. Water level fluctuations caused by dam operations or seasonal drawdowns can eliminate breeding habitat for bullfrogs. Visit/wildlife/maine/bullfrogfor more details on local protections. Landowners can support bullfrogs by maintaining natural shorelines and avoiding pesticide use near water. If you encounter bullfrogs, observe them quietly from a distance without handling or disturbing them. Maine's amphibian populations face pressures from disease, parasites, and habitat alteration, making protection efforts important for long-term survival.
Species Commonly Confused with Bullfrogs
Several other frog species in Maine could be mistaken for bullfrogs by the untrained eye, though bullfrogs are distinctly larger. American toads are small, bumpy-skinned toads that lack the smooth skin and large tympanum of bullfrogs. Green frogs are smaller than bullfrogs, typically four to four and a half inches long, with a more slender build and a white stripe down the center of the back. Leopard frogs have prominent spots and a more streamlined shape, making them easily distinguished from the stocky bullfrog. Pickerel frogs are small with distinctive checkered patterns and bright orange coloring on their hindlegs. Wood frogs have a dark mask across their eyes and are significantly smaller. Spring peepers are tiny chorus frogs, less than an inch and a half long, with an X marking on their backs. Gray tree frogs are small climbing frogs with warty skin and sucking toe pads. The bullfrog's large size, prominent tympanum, smooth skin, and massive build make it unmistakable once you understand these distinguishing features.
Frequently Asked Questions
What does a Maine bullfrog sound like? Bullfrogs produce a deep, resonant call that sounds like jug-o-rum or brrock-brrock, especially during breeding season in summer. They are Maine's loudest frogs and can be heard from considerable distances across wetlands. Are bullfrogs native to Maine? Yes, bullfrogs are native to the eastern United States, including Maine, though they are more abundant in warmer southern states. When are bullfrogs most active in Maine? Bullfrogs are most active from May through September, with peak activity in July and August. Listen for their calls at dusk and dawn on warm evenings. Can I keep bullfrogs as pets in Maine? No, Maine law prohibits collecting or keeping native bullfrogs without permits. Bullfrogs collected from other states can sometimes be kept if regulations are followed, but wild Maine frogs are protected. How long do bullfrogs live? In the wild, bullfrogs typically live five to ten years, though some live longer. In captivity, they can live fifteen to twenty years with proper care.
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