Grenouille des bois— Quebec wildlife

Lithobates sylvaticus or Rana sylvatica, commonly known as the wood frog, is a frog species that has a broad distribution over North America, extending from the boreal forest of the north to the southern Appalachians, with several notable disjunct populations including lowland eastern North Carolina. The wood frog has garnered attention from biologists because of its freeze tolerance, relatively great degree of terrestrialism (for a ranid), interesting habitat associations (peat bogs, vernal pools, uplands), and relatively long-range movements. It is the only North American frog that occurs north of the Arctic Circle. The ecology and conservation of the wood frog has attracted research attention in recent years because they are often considered "obligate" breeders in ephemeral wetlands (sometimes called "vernal pools"), which are themselves more imperiled than the species that breed in them. The wood frog has been proposed to be the official state amphibian of New York.

Description

Wood frogs range from 51 to 70 mm (2.0 to 2.8 in) in length. Females are larger than males. Adult wood frogs are usually brown, tan, or rust-colored, and usually have a dark eye mask. Individual frogs are capable of varying their color; Conant (1958) depicts one individual which was light brown and dark brown at different times. The underparts of wood frogs are pale with a yellow or green cast; in northern populations, the belly may be faintly mottled. Their body colour may change seasonally; exposure to sunlight causes darkening.

Habitat and range

Wood frogs are forest-dwelling, and breed primarily in ephemeral, freshwater wetlands: woodland vernal pools. They are nonarboreal, and able to camouflage themselves with their surroundings, spend most of their time on the forest floor. Long-distance migration plays an important role in their life history. Individual wood frogs range widely (hundreds of metres) among their breeding pools and neighboring freshwater swamps, cool-moist ravines, and/or upland habitats. Genetic neighborhoods of individual pool breeding populations extend more than a kilometre away from the breeding site. A study was done on wood frogs dispersal patterns in five ponds at the Appalachian Mountains, which reported adult wood frogs were 100% faithful to the pond of their first breeding but 18% of juveniles dispersed to breed in other ponds. Adult wood frogs spend summer months in moist woodlands, forested swamps, ravines, or bogs. During the fall, they leave summer habitats and migrate to neighboring uplands to overwinter. Some may remain in moist areas to overwinter. Hibernacula tend to be in the upper organic layers of the soil, under leaf litter. By overwintering in uplands adjacent to breeding pools, adults ensure a short migration to thawed pools in early spring. Wood frogs are mostly diurnal and are rarely seen at night, except maybe in breeding choruses. Along with spring peepers, they are one of the first amphibians to emerge for breeding right after snowmelt.