Details
Lithobates sylvaticus
The wood frog is a small forest frog famous for surviving partial freezing through winter. A dark mask behind the eye gives it a distinctive face.
Map: Ecoregions 2017 © RESOLVE (CC BY 4.0) · Natural Earth (PD)
It ranges from Alaska across Canada into the northeastern United States, living on damp floors of deciduous and coniferous forest. Breeding draws it to temporary ponds and snowmelt pools.
Adults are about 3.5-8.3 cm long. The body may be brown, reddish or gray, with a dark band running from the eye past the tympanum and a pale underside.
Usually solitary, it moves through leaf litter and overwinters beneath it, tolerating freezing temperatures. In early spring, adults appear suddenly at breeding pools.
It eats insects, spiders, worms and small arthropods. Tadpoles feed on algae and organic matter in shallow pools.
Breeding is brief and explosive, with males calling in shallow ponds soon after thaw. Egg masses are laid near the surface, where temporary water warms quickly.
The species depends on forest wetlands and seasonal ponds, so roads and development can fragment breeding habitat. Its freeze tolerance is a model for physiological research.
