Eastern Gray Treefrog (Hyla versicolor) or Cope's Gray Treefrog (Hyla chrysoscelis)
Order: Anura, Family: Hylidae (Treefrogs), Genus: Hyla. These species are members of the Holarctic treefrog group, characterized by specialized toe pads for arboreal lifestyles.
Species
Eastern Gray Treefrog (Hyla versicolor) or Cope's Gray Treefrog (Hyla chrysoscelis)
Family
Order: Anura, Family: Hylidae (Treefrogs), Genus: Hyla. These species are members of the Holarctic treefrog group, characterized by specialized toe pads for arboreal lifestyles.
Size
Adults typically range from 1.25 to 2 inches (32-51 mm) SVL. At the newly metamorphosed stage seen here, they are approximately 0.5 to 0.75 inches long. Females are generally larger than males.
Conservation
IUCN Status: Least Concern. Populations are generally stable and they adapt well to suburban environments, though sensitive to heavy pesticide use and habitat fragmentation.
Description
A charming, 'mossy' resident of Michigan woodlands. Though they are often heard rather than seen, finding a newly emerged bright green metamorph is a highlight for any naturalist. They represent the perfect link between the water and the forest canopy.
Key Features
Large adhesive toe pads; light-colored square or spot under each eye; granular skin; bright yellow/orange inner thighs (hidden when sitting).
Physical Description
A small, robust treefrog with a rounded snout and large, prominent eyes with horizontal pupils. The limbs are well-developed for climbing, featuring significantly enlarged, adhesive toe pads. The tympanum (eardrum) is distinct and slightly smaller than the eye.
Skin Texture & Coloration
Skin is notably granular or 'warty' for a treefrog. Coloration is highly variable (versicolor means 'many colors'), ranging from bright lime green (common in metamorphs like this one) to mottled gray, brown, or lichen-green. The inner thighs possess hidden bright yellow or orange wash (flash colors).
Distinguishing Features
Large toe pads and a white spot directly beneath the eye are diagnostic. The hidden yellow/orange wash on the femoral region is a key marker. In Michigan, H. versicolor and H. chrysoscelis are 'cryptic species'—looking identical but differing in chromosome count and call pulse rate.
Habitat
Broadleaf and mixed forests, often near permanent or ephemeral water sources such as ponds, swamps, or backyard water features. They are largely arboreal, spending much of their time high in the canopy except during breeding.
Geographic Range
Widespread across the Eastern United States and Southeastern Canada. In Michigan, both species are present, though the Eastern Gray Treefrog is more ubiquitous in the northern and central parts of the state.
Behavior
Nocturnal and highly arboreal. They are expert hiders, using their cryptic coloration to blend into tree bark. When threatened, they may remain motionless or use 'flash colors' on their legs to startle predators during a leap.
Diet & Feeding
Primarily insectivorous, consuming spiders, ants, beetles, moths, and crickets. They use a sit-and-wait ambush strategy, often hunting near porch lights where insects congregate.
Reproduction
Breeding occurs from late spring to early summer (May-July in Michigan) triggered by warm rains. Amplexus is axillary. Eggs are laid in small clusters or floating rafts attached to vegetation in quiet water.
Vocalizations
H. versicolor has a slow, melodic bird-like trill. H. chrysoscelis has a faster, harsher, more metallic trill. The call is the only reliable way to distinguish the two in the field.
Life Cycle
Eggs hatch in 3-7 days. Tadpoles have distinctive reddish or orange-tinted tails to distract predators. Metamorphosis occurs in 6-8 weeks. This specimen is a 'metamorph,' having just transitioned from aquatic to terrestrial life.
Conservation Status
IUCN Status: Least Concern. Populations are generally stable and they adapt well to suburban environments, though sensitive to heavy pesticide use and habitat fragmentation.
Toxicity & Defense
Mildly toxic skin secretions can irritate human mucous membranes (eyes/nose). The primary defense is camouflage and the flash of orange on the thighs to confuse attackers.
Ecological Role
Significant controllers of insect populations. They serve as a vital food source for birds, snakes, and larger frogs. Their presence indicates a healthy, connected forest-wetland ecosystem.
Similar Species
Spring Peeper (Pseudacris crucifer) is smaller with an 'X' on the back; Blanchard's Cricket Frog (Acris blanchardi) has smaller toe pads and a triangular head mark.
Observation Tips
Listen for trilling choruses on warm, humid evenings near ponds. Use a flashlight to scan tree trunks or low vegetation. Metamorphs like this one are often found in tall grass near the water's edge in July.
Handling & Safety
Safe to hold briefly, but always wash hands afterward to avoid irritation from skin toxins. Keep your hands moist; oils and salts from human skin can dehydrate or stress the frog. Do not touch your eyes after handling.
Seasonal Activity
Active from late April through October. They spend the winter in a state of brumation, partially frozen under logs or leaf litter, becoming active once temperatures consistently stay above freezing.
Cultural Significance
Often viewed as a harbinger of rain due to their tendency to call during high humidity. They are popular 'backyard' amphibians that foster a connection between suburban residents and local biodiversity.
Interesting Facts
The Eastern Gray Treefrog is tetraploid (four sets of chromosomes), while Cope's is diploid (two sets). They are also freeze-tolerant, producing glycerol to protect cells during winter hibernation under leaf litter.
Notes
Found in Stoney Creek Michigan. Was a pollygon 24-48 hours ago and just absorbed his tail.