List of Frog Species in Connecticut (ID + Pictures)

Connecticut is situated in southern New England and is the third-smallest state by area. Its landscapes are characterized by coastal cities and rural areas interspersed with towns. Away from the urban areas, this state boasts extensive forests (with over 60% of it being forested) as well as wetlands such as marshes, swamps, wet meadows, and lakes.

The state experiences cold, snowy winters and warm, humid summers, although the presence of the jet stream causes the weather to be somewhat variable. Several species of frog can be found in Connecticut, most of which occupy wooded areas or meadows.

Connecticut Frogs 

1) Green frog (Lithobates clamitans)

• Native to eastern North America
• Family: Ranidae
• Order: Anura
• Conservation status: Least concern

The green frog ranges from 5.1 – 10.2 cm (2 – 4 in) in length, although its size varies with altitude – individuals are larger at higher elevations due to the colder temperatures. This frog is green in color with light brown mottling across the dorsum, while its underside is white with dark spots. Green frogs are sexually dimorphic: males display a yellow throat and large tympana.

Lithobates clamitans can be observed throughout Connecticut, where they reside in a variety of habitats such as swamps, ponds, lakes, and marshes, although individuals may venture into meadows and woodlands during wet weather. The food consumption of this species varies depending on the time of year: a greater proportion of aquatic organisms are consumed during the winter, whereas individuals forage for terrestrial organisms more in the summer.

During breeding season, male green frogs maintain territories – it is thought that they establish these early on in the season and then remain in the same position throughout. Males advertise to females using a distinctive mating call.

2) Pickerel frog (Lithobates palustris)

• Native to the US
• Family: Ranidae
• Order: Anura
• Conservation status: Least concern

The pickerel frog reaches lengths of 5.1 – 7.6 cm (2 – 3 in) and has a pale tan-colored dorsum with a patterning of dark brown squares. The dorsolateral lines are cream in color, the underside is white, and the inside of the thighs are yellow or orange. Pickerel frogs show geographic variation in appearance, with differences in the number of dorsal markings depending on the area populations are located in.

Lithobates palustris is common in Connecticut, typically occupying wooded or meadow areas with dense vegetation, close to streams. Adult individuals feed on insects, snails, and earthworms, whereas tadpoles consume plant material.

Some populations of pickerel frogs may face threats such as urbanization, road construction, and habitat loss due to logging. Studies suggest that conservation strategies need to account for the movements (particularly during breeding migrations) of frogs across roads.

3) Northern leopard frog (Lithobates pipiens)

• Native to North America (except for the Pacific Coast)
• Family: Ranidae
• Order: Anura
• Conservation status: Least concern

Lithobates pipiens is between 5 – 11 cm (2 – 4.3 in) in length and has a slender build with prominent dorsolateral folds. The coloration of this species is brown or green, with dark spots surrounded by pale borders on the dorsum. The underside is pale, and there is a white stripe on the upper jaw.

Despite populations being stable overall, the northern leopard frog is designated as a species of special concern in Connecticut. Within the state, it can only be found in isolated populations along the Connecticut River. Adults typically inhabit wet meadows and forests, where they seek areas with moist soil, standing water, and plenty of vegetation.

Likely threats to populations of the northern leopard frog include habitat loss due to urbanization, logging, and farming, as well as pollution and invasive species. This species will commonly try to cross roads, which often results in fatality.

4) American bullfrog (Lithobates catesbeianus)

• Native to the Atlantic Coast
• Family: Ranidae
• Order: Anura
• Conservation status: Least concern

The American bullfrog is a very large anuran, with record lengths of up to 20 cm (8 in). This species’ size makes it quite distinctive, but another key distinguishing feature is the large tympanum (which is bigger in males than it is in females). Bullfrogs are green with light brown blotches across the dorsum, while the underside is white with gray markings. Males display a yellow throat.

Lithobates catesbeianus is common throughout Connecticut, where it can usually be observed in or around permanent water bodies. As the weather becomes colder in the fall, this frog begins hibernation, usually by burying itself in mud at the bottom of a body of water.

American bullfrogs are voracious predators, consuming any prey that they can fit in their mouths. Common items include salamanders, crayfish, small mammals, birds, and other frogs. The tadpoles feed on plant material.

5) Spring peeper (Pseudacris crucifer)

• Native to eastern North America
• Family: Hylidae
• Order: Anura
• Conservation status: Least concern

The spring peeper is a small species of treefrog that reaches 2.5 cm (1 in) in length. This species has a slender build and possesses a large vocal sac that inflates like a balloon to produce the characteristic ‘peeping’ noise. The coloration of this frog enables it to blend in with tree bark, being a combination of tan, brown, green, and gray, with an X-shaped pattern on the back.

Pseudacris crucifer can be seen throughout much of Connecticut, where it resides in moist areas of forests, fields, and even residential areas. This frog is nocturnal and has a varied diet, including but not limited to ants, beetles, flies, ticks, caterpillars, and springtails.

During the winter months, spring peepers seek refuge in underground burrows or underneath leaf litter. This species can tolerate freezing, with various metabolic processes taking place within the individual’s body to ensure its survival.

6) Wood frog (Lithobates sylvaticus)

• Native to northeastern North America
• Family: Ranidae
• Order: Anura
• Conservation status: Least concern

The wood frog ranges in length from 3.8 – 8.2 cm (1.5 – 3.2 in) and has a slender build with prominent dorsolateral folds. This frog varies in color – individuals can be green, gray, brown, or red, and somewhat unusually, females are more brightly colored than males. There is a black mask across the eye.

Lithobates sylvaticus can be found in forested habitats throughout Connecticut. It is usually within close proximity of woodland ponds, and if these dry up during the summer months individuals are reported to follow the waterline, eventually burrowing underneath leaf litter if the water disappears entirely.

This species reproduces shortly after the first warm spring rains, migrating to breeding sites. Males call to the females, with eggs being deposited shortly after, and the tadpole phase lasts for around two and a half months before metamorphosis takes place.

7) Gray treefrog (Dryophytes versicolor)

• Native to the eastern US
• Family: Hylidae
• Order: Anura
• Conservation status: Least concern

The gray treefrog is sexually dimorphic: males are slightly smaller than females, with their lengths being 3.2 – 5.1 cm (1.3 – 2 in) and 3.3 – 6 cm (1.3 – 2.4 in) respectively. This species has a round body with long limbs and large adhesive pads on its feet. Its coloration can be green, gray, or brown, with irregular dark markings on the dorsum.

In Connecticut, Dryophytes versicolor can be found in moist areas, usually concealing itself high up in trees or in shrubbery near a body of water. Individuals feed predominantly on ants and beetles – the availability of prey varies depending on the types of trees in which hunting takes place, thus, the preservation of suitable habitat is essential for the success of this species.

Although populations of the gray treefrog are stable, they may be affected by urbanization and road construction. The changes to habitats caused by harvesting timber may also affect breeding activities.

8) Atlantic Coast leopard frog (Lithobates kauffeldi)

• Native to the northeastern US
• Family: Ranidae
• Order: Anura
• Conservation status: Least concern

The Atlantic Coast leopard frog attains lengths of 5.1 – 9 cm (2 – 3.5 in) and has a slim body with large dorsolateral folds. Its dorsal coloration is a dull olive green or brown with small dark spots – this species can be distinguished from the northern leopard frog because it has fewer spots.

The distribution of Lithobates kauffeldi is limited; having only recently been described for the first time, the species is known from just a handful of locations. Studies into the mitochondrial DNA of this species have shown that it is more closely related to the pickerel frog than it is to other leopard frogs!

Although the overall conservation status of the Atlantic Coast leopard frog is that of least concern, its status in Connecticut has not yet been assessed. This frog may face threats such as urbanization, road construction, invasive species, climate change, and habitat fragmentation.