Wood frog

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 underparts of wood frogs are pale with a yellow or green cast;[8] in northern populations, the belly may be faintly mottled.

[9] The contiguous wood frog range is from northern Georgia and northeastern Canada in the east to Alaska and southern British Columbia in the west.

Wood frogs are forest-dwelling organisms that breed primarily in ephemeral, freshwater wetlands: woodland vernal pools.

Individual wood frogs range widely (hundreds of metres) among their breeding pools and neighboring freshwater swamps, cool-moist ravines, and/or upland habitats.

[13] Adult wood frogs spend summer months in moist woodlands, forested swamps, ravines, or bogs.

Wood frogs eat a variety of small, forest-floor invertebrates, with a diet primarily consisting of insects.

[17][18] Urea is accumulated in tissues in preparation for overwintering,[citation needed] and liver glycogen is converted in large quantities to glucose in response to internal ice formation.

Both urea and glucose act as cryoprotectants to limit the amount of ice that forms and to reduce osmotic shrinkage of cells.

However, wood frogs in Interior Alaska exhibit even greater tolerance, with some of their body water freezing while still surviving.

One crucial mechanism utilized by the wood frog is the accumulation of high amounts of glucose that act as a cryoprotectant.

Wood frogs have a series of seven amino acid substitutions in the sarco/endoplasmic reticulum Ca2+-ATPase 1 (SERCA 1) enzyme ATP binding site that allows this pump to function at lower temperatures relative to less cold-tolerant species (e.g. Lithobates clamitans).

[22] Studies on northern subpopulations found that Alaskan wood frogs had a larger liver glycogen reserve and greater urea production[23] compared to those in more temperate zones of its range.

[6][26][29] 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, and have more protection from predators.

[26][30][35] The success of the larvae and tadpoles is important in populations of wood frogs because they affect the gene flow and genetic variation of the following generations.

Another conservation concern is that wood frogs are primarily dependent on smaller, "geographically isolated" wetlands for breeding.

[1] The wood frog has a complex lifecycle that depends on multiple habitats, damp lowlands, and adjacent woodlands.

[1] Wood frog development in the tadpole stage is known to be negatively affected by road salt contaminating freshwater ecosystems.

[33] Tadpoles have also been shown to develop abnormalities due to a combination of warmer conditions and toxic metals from pesticides near their habitats.

Wood frog demonstrating lighter skin tones, New Jersey Pine Barrens
Showing ground leaf camouflage pattern, Darien Lakes State Park
Showing dark skin tones, Mer Bleue Conservation Area
Depicting a pinkish-tan skin tone, White Clay Creek
Spring mating calls
Picture of a wood frog on the shoreline of Kabekona Lake , Minnesota
Lithobates sylvaticus found in southern Quebec