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wood frog
rana sylvatica
53.4874, -114.175
Field Notes
Description:
Wood frogs range from 51 millimetres (2.0 in) to 70 millimetres (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 when light brown and dark brown at different times. The underparts of wood frogs are pale with a yellow or green cast.
Mer Bleue Conservation Area, showing dark skin tones
If you see a small brown frog with a dark eye mask in the woods, it is likely to be a wood frog. There are no other species with a similar appearance to the wood frog in North America. The first evasive leap is fast and long. Close observation will often glimpse a second short dive under the leaf litter, making the frog appear to disappear.
Habitat:
Wood frogs are forest-dwelling organisms that breed primarily in ephemeral, freshwater wetlands: woodland vernal pools. Long-distance migration plays an important role in their life history. Individual wood frogs range widely (hundreds of meters) 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 kilometer away from the breeding site. Thus, conservation of this species requires a landscape (multiple habitats at appropriate spatial scales) perspective
Wood Frogs calling in spring.ogg
Spring mating calls
Rana sylvatica primarily breeds in ephemeral pools rather than permanent water bodies such as ponds or lakes. This is believed to provide some protection of the adult frogs and their offspring (eggs and tadpoles) from predation by fish and other predators of permanent water bodies. Adult wood frogs emerge from hibernation in early spring and migrate to nearby pools. There, males chorus, emitting duck-like quacking sounds. Females deposit eggs attached to submerged substrate, typically vegetation or downed branches. Most commonly, females will deposit eggs adjacent to other egg masses, creating large aggregations of masses. Some advantage is conferred to pairs first to breed, as clutches closer to the center of the raft absorb heat and develop faster than those on the periphery. If pools dry before tadpoles metamorphose into froglets, they die. This constitutes the risk counterbalancing the anti-predator protection of ephemeral pools. By breeding in early spring, however, wood frogs increase their offspring's chances of metamorphosing before pools dry. Following metamorphosis, a small percentage (less than 20%) of juveniles will disperse, permanently leaving the vicinity of their natal pool. The majority of offspring are philopatric, returning to their natal pool to breed.
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, adult Rana sylvatica ensure a short migration to thawed pools in early spring. Because they live in cold areas, wood frogs are usually active during daytime and are rarely seen at night, except maybe in breeding choruses. They are one of the first amphibians to emerge for breeding right when the snow melts, along with Spring Peepers.
Notes:
I saw this little guy on a trail near Hasse lake. there were literally hundreds but I guess this was the only photogenic one. There are also tons of them at spring lake, they are always in shallow water, reeds, or, as you can see in the picture, deep grass.
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