Gray Treefrog (Dryophytes versicolor) or Cope’s Gray Treefrog (Dryophytes chrysoscelis)
Order Anura, Family Hylidae, Genus Dryophytes. This genus was formerly part of Hyla and contains small to medium-sized arboreal frogs characterized by enlarged adhesive toe pads.
Species
Gray Treefrog (Dryophytes versicolor) or Cope’s Gray Treefrog (Dryophytes chrysoscelis)
Family
Order Anura, Family Hylidae, Genus Dryophytes. This genus was formerly part of Hyla and contains small to medium-sized arboreal frogs characterized by enlarged adhesive toe pads.
Size
Adult SVL typically ranges from 1.25 to 2 inches (32–51 mm). Females are generally larger than males. Metamorphs are much smaller, often bright emerald green when they first emerge from the water.
Conservation
Listed as Least Concern by the IUCN. Populations are generally stable, though they face local threats from habitat fragmentation, pesticide use, and the loss of ephemeral breeding pools.
Description
A master of disguise, the Gray Treefrog looks like a living piece of lichen against a tree trunk. This medium-sized amphibian is a common visitor to porch lights in the eastern US, where its spectacular climbing skills and 'sticky' toes allow it to scale vertical walls with ease. Its scientific name 'versicolor' refers to its remarkable ability to shift its base color from mottled gray to vibrant green in minutes.
Key Features
Bright yellow/orange concealed inner thighs, a light square-shaped spot below the eye, and granular, lichen-patterned skin.
Physical Description
Medium-sized, robust frogs with a somewhat flattened body. They possess large, rounded adhesive toe pads on all digits and significant webbing on the hind feet. The eyes are prominent with dark pupils and golden-brown or copper irises. The tympanum (eardrum) is distinct but smaller than the eye.
Skin Texture & Coloration
The skin is distinctly granular or 'warty' for a treefrog. Coloration is highly variable and can change from light gray to green or brown to match the substrate (metachrosis). They typically feature a dark, irregular star-shaped or lichen-like blotch on the back. Ventral surface is white, while the inner thighs feature bright yellow or orange wash (flash colors).
Distinguishing Features
The most diagnostic feature is the bright yellow or orange wash on the inner thighs, combined with a light-colored spot beneath the eye. The granular skin and lichen-like pattern distinguish it from the smooth-skinned Green Treefrog.
Habitat
Highly arboreal, inhabiting mixed deciduous forests, swamps, and suburban backyards near water. They are often found on trees, shrubs, or clinging to the siding of houses near outdoor lights.
Geographic Range
Eastern North America, from southern Canada throughout the eastern United States as far west as central Texas and the Great Plains. D. versicolor is more common in the north, while D. chrysoscelis is more common in the south, though ranges overlap significantly.
Behavior
Primarily nocturnal. They are excellent climbers that spend the day tucked into tree cavities or under bark to conserve moisture. When threatened, they rely on camouflage or leap away, revealing their bright orange groin to startle predators.
Diet & Feeding
Insectivorous. They are active nocturnal foragers, often congregating near porch lights to feast on moths, crickets, beetles, and flies attracted to the illumination.
Reproduction
Breed in spring and early summer, typically triggered by heavy rains. Males call from the edges of or vegetation overhanging temporary ponds and swamps. Amplexus is axillary. Females lay up to 2,000 eggs in small clusters attached to vegetation at the water's surface.
Vocalizations
The two species are visually identical and are best distinguished by call: D. versicolor has a slow, melodic trill, while D. chrysoscelis has a faster, harsher, higher-pitched trill. The rate of the trill is temperature-dependent.
Life Cycle
Eggs hatch in 3–6 days. Tadpoles have high, often reddish-tinted tail fins to distract predators. Metamorphosis occurs in 6–8 weeks. Juveniles are often bright green. They reach sexual maturity in about 2 years and can live 7–9 years.
Conservation Status
Listed as Least Concern by the IUCN. Populations are generally stable, though they face local threats from habitat fragmentation, pesticide use, and the loss of ephemeral breeding pools.
Toxicity & Defense
Their skin secretions are mildly toxic to mucous membranes; contact with eyes or mouth can cause a burning sensation (bufadienolides). The bright orange inner thighs act as 'flash colors' to startle and confuse predators during a jump.
Ecological Role
They serve as a vital link in the food chain, consuming vast quantities of night-flying insects while serving as prey for birds, snakes, and larger amphibians.
Similar Species
The Gray Treefrog and Cope's Gray Treefrog are 'cryptic species,' meaning they look identical and are only distinguished by their chromosome count (tetraploid vs. diploid) or their calls. The Green Treefrog is much smoother and usually has a distinct white lateral stripe.
Observation Tips
Best found on warm, humid nights during the spring and summer. Scan the siding of buildings or trees near porch lights. In early summer, listen for their trilling choruses near ponds and flooded ditches.
Handling & Safety
Generally safe to move if necessary, but wash hands thoroughly after contact as skin secretions can irritate the eyes. Always wash hands before handling to protect the frog from oils/chemicals on human skin.
Seasonal Activity
Active from early spring through autumn. During winter, they hibernate in leaf litter or under bark, utilizing their specialized blood chemistry to survive sub-freezing temperatures.
Cultural Significance
Often considered the 'classic' treefrog of the American East and Midwest. It is a frequent subject of nature photography and is valued as a natural form of pest control in gardens and suburban neighborhoods.
Interesting Facts
Gray Treefrogs are freeze-tolerant. They produce glycerol in their blood, which acts as a natural antifreeze, allowing them to survive having a large portion of their body water turn to ice during winter hibernation.