Gray Treefrog (Hyla versicolor) or Cope’s Gray Treefrog (Hyla chrysoscelis)
Order Anura, Family Hylidae, Genus Hyla. These are typical 'New World' treefrogs characterized by large adhesive toe pads and an arboreal lifestyle.
Species
Gray Treefrog (Hyla versicolor) or Cope’s Gray Treefrog (Hyla chrysoscelis)
Family
Order Anura, Family Hylidae, Genus Hyla. These are typical 'New World' treefrogs characterized by large adhesive toe pads and an arboreal lifestyle.
Size
Adults range from 1.25 to 2.25 inches (3.2–5.7 cm) SVL. Females are generally larger than males. Juveniles are much smaller and often bright green upon metamorphosis.
Conservation
IUCN Status: Least Concern. Populations are stable, although habitat fragmentation and pesticide runoff in suburban areas can local impacts.
Description
An iconic North American amphibian often felt before it is seen. Its skin is a masterpiece of camouflage, mimicking tree bark and lichen perfectly. In the image, we see a rare perspective: the 'underbelly' view as it clings to glass, showcasing the secret bright orange markings hidden when at rest.
Key Features
Large toe pads, granular ventral skin, and vivid yellow/orange wash with dark mottling on the hidden surfaces of the hind legs.
Physical Description
A medium-sized, somewhat robust treefrog with a rounded snout and large, prominent eyes. It features large, sticky toe pads and moderate webbing on the hind feet. The ventral view (visible in the image) reveals a pale belly and the diagnostic bright coloration on the inner thighs.
Skin Texture & Coloration
The dorsal skin is granular and resembles lichen; however, the ventral side is smoother and creamy-white. Most notably, the inner thighs and groin area exhibit bright yellow to orange aposematic coloration with dark mottling or black spots.
Distinguishing Features
The most effective field mark is the bright yellow-orange 'flash colors' on the inner surface of the hind legs. They also typically have a light square spot beneath each eye. From below, the combination of large toe pads and yellow inner thighs is diagnostic for this species complex.
Habitat
Arboreal; found in deciduous forests, woodlots, and swamps. They often inhabit backyard gardens and are frequently seen on windows, decks, or near porch lights where insects are attracted.
Geographic Range
Common throughout the Eastern United States and Southeastern Canada, from the Atlantic coast west to Texas and Manitoba.
Behavior
Nocturnal and highly arboreal. They are excellent climbers. When threatened, they rely on lichen-like camouflage or 'flash' their bright orange thighs while jumping to startle predators.
Diet & Feeding
Insectivorous. They use a sit-and-wait strategy to catch moths, beetles, crickets, and flies. They are often found on windows at night because they have learned that lights attract high densities of prey.
Reproduction
Explosive breeders in spring and early summer. Breeding occurs in fishless permanent or temporary ponds. Amplexus is axillary. Females can lay up to 2,000 eggs in small loose clusters attached to vegetation.
Vocalizations
H. versicolor has a slow, melodic trill. H. chrysoscelis has a faster, harsher, higher-pitched trill. This is the primary way to distinguish the two species in the field, as they are visually identical.
Life Cycle
Eggs hatch in 3–7 days. Tadpoles have distinctive reddish or orange-tinted tails. Metamorphosis occurs in 45–65 days. Adults can live 7–9 years in the wild.
Conservation Status
IUCN Status: Least Concern. Populations are stable, although habitat fragmentation and pesticide runoff in suburban areas can local impacts.
Toxicity & Defense
The skin produces a toxic secretion that can be irritating to human mucous membranes (eyes/nose/mouth). The orange inner thighs serve as flash coloration to confuse predators.
Ecological Role
Primary consumer of nocturnal insects and a source of food for birds, snakes, and larger frogs. They serve as excellent indicators of wetland and forest health.
Similar Species
The Gray Treefrog and Cope's Gray Treefrog are 'cryptic species' and look identical. The Green Treefrog (Hyla cinerea) lacks the granular skin and the yellow-orange inner thighs.
Observation Tips
Check windows or glass doors near outdoor lights on warm, humid nights. Listen for their trilling calls near ponds during spring rains.
Handling & Safety
Avoid touching your eyes or mouth after handling due to skin secretions. Always wash hands thoroughly. Use wet hands if handling is necessary to protect the frog's permeable skin.
Seasonal Activity
Active from early spring (March/April) through October. They hibernate under leaf litter, bark, or in tree cavities during the winter.
Cultural Significance
Commonly known as 'weather frogs,' as people often notice them calling more frequently before or during rainstorms.
Interesting Facts
These frogs produce glycerol (a biological antifreeze) in their blood, allowing them to survive freezing temperatures during winter hibernation.