Gray Treefrog (Dryophytes versicolor) or Cope’s Gray Treefrog (Dryophytes chrysoscelis)
Order Anura, Family Hylidae (Treefrogs), Genus Dryophytes. These are North American hylids characterized by large adhesive toe pads and the ability to change color between gray and green.
Species
Gray Treefrog (Dryophytes versicolor) or Cope’s Gray Treefrog (Dryophytes chrysoscelis)
Family
Order Anura, Family Hylidae (Treefrogs), Genus Dryophytes. These are North American hylids characterized by large adhesive toe pads and the ability to change color between gray and green.
Size
Adult SVL typically ranges from 1.25 to 2.25 inches (3.2 to 6 cm). Females are generally slightly larger than males. Weight is between 6 to 10 grams.
Conservation
IUCN Status: Least Concern. Populations are stable, although they are sensitive to water pollution and loss of wetlands near forested areas.
Description
A master of camouflage, the Gray Treefrog looks like a living piece of lichen. Its bumpy skin and mottled pattern allow it to disappear against tree bark. In this image, it is seen on a blue artificial surface, which highlights its pale, rough texture.
Key Features
Light spot under the eye, warty/granular skin, lichen-like pattern, large toe pads, and bright yellow/orange hidden inner thighs.
Physical Description
Robust and chunky for a treefrog. Features a short snout, large protruding eyes with horizontal pupils, and prominent tympana. Limbs are moderately long with large, rounded toe pads for climbing.
Skin Texture & Coloration
Skin is distinctly granular and warty, resembling lichen on tree bark. Color varies from pale gray to light green with dark, blotchy irregular markings. Undersurfaces of the hind legs are bright yellow or orange (flash colors).
Distinguishing Features
White square-shaped patch beneath each eye. Large toe pads and a lichen-like pattern. Flash colors on the hidden parts of the inner thighs are diagnostic for this species complex.
Habitat
Arboreal; found in deciduous forests, woodlots, suburban backyards, and swamps. They require temporary or permanent ponds for breeding but spend most of their time high in the forest canopy.
Geographic Range
Eastern United States and southeastern Canada. Range extends from Manitoba to Texas and east to the Atlantic coast. The two species overlap significantly in the eastern half of the US.
Behavior
Primarily nocturnal. They are excellent climbers. When threatened, they crouch flat to resemble a bump on a branch. They are rarely seen during the day as they hide in tree cavities or under bark.
Diet & Feeding
Insectivorous. Diet includes moths, beetles, crickets, ants, spiders, and occasionally smaller frogs. They use a sit-and-wait ambush strategy, often hunting near porch lights where insects congregate.
Reproduction
Breeding occurs from late spring to mid-summer, often triggered by heavy rain. Amplexus is axillary. Eggs are laid in small clusters or loose masses (10-40 eggs) attached to vegetation in ponds.
Vocalizations
The two species are identical in appearance but have different calls: D. versicolor has a slow, melodic trill; D. chrysoscelis has a faster, harsher, higher-pitched trill. The call is a loud, bird-like 'brrr-rr-rr-rp'.
Life Cycle
Eggs hatch in 3-6 days. Tadpoles have colorful reddish or orange tails with black spots. Metamorphosis occurs in 45-65 days. Juveniles are often bright green. Maturity is reached in 2 years.
Conservation Status
IUCN Status: Least Concern. Populations are stable, although they are sensitive to water pollution and loss of wetlands near forested areas.
Toxicity & Defense
While not lethal to humans, they produce skin secretions that can be highly irritating to mucous membranes (eyes and mouth). The bright yellow thighs serve as 'flash coloration' to startle predators.
Ecological Role
Important control agent for insect populations. They serve as prey for snakes (like Garter snakes), birds, and small mammals.
Similar Species
The two species (D. versicolor and D. chrysoscelis) are 'cryptic' and can only be reliably distinguished by their calls or chromosome counts (one is diploid, the other tetraploid).
Observation Tips
Look for them on rainy summer nights near window screens or porch lights where they hunt bugs. Follow the sound of the loud trilling chorus near wooded ponds in May and June.
Handling & Safety
Avoid touching your eyes after handling, as their skin secretions cause a burning sensation. Always wash hands thoroughly. Use wet hands if handling is necessary to protect their permeable skin.
Seasonal Activity
Active from April to October. They spend the winter hibernating under leaf litter, logs, or in frozen tree cavities, emerging once temperatures consistently stay above freezing.
Cultural Significance
A common 'backyard' frog in North America, its summer trill is a staple of night sounds in the Eastern US. It serves as a popular symbol of forest health.
Interesting Facts
Gray Treefrogs are freeze-tolerant. They can survive the winter with up to 40% of their body water turned to ice by producing glycerol as a natural antifreeze.