Wood Frog
Lithobates sylvaticus
Quick answer
The wood frog is a small, cold-hardy frog of North America, recognizable by the dark 'robber's mask' across its eyes. It is remarkable for surviving winter by letting much of its body freeze solid and then thawing in spring. Wood frogs typically live around 3 years in the wild.
Wood Frog facts at a glance
| Scientific name | Lithobates sylvaticus |
|---|---|
| Diet | Insectivore (insects, spiders, slugs) |
| Habitat | Forests and woodland near temporary pools |
| Lifespan | About 3 years in the wild |
| Weight | About 8 g (0.3 oz) |
| Size | 3.5–7 cm (1.4–2.8 in) body length |
| Conservation status | Least Concern (IUCN) |
| Kingdom | Animalia |
|---|---|
| Phylum | Chordata |
| Class | Amphibia |
| Order | Anura |
| Family | Ranidae |
| Genus | Lithobates |
Where it lives
Forests across northern North America, ranging farther north than any other frog, even above the Arctic Circle.
Behavior and freeze tolerance
Wood frogs are famous for their ability to survive being frozen. In winter, up to two-thirds of the water in their body can turn to ice while their heart and breathing stop, protected by high levels of glucose acting as a natural antifreeze in their cells. When temperatures rise in spring, they thaw and resume activity, often becoming some of the first frogs to breed.
Diet and feeding
Wood frogs are insectivores that forage on the forest floor. They eat insects, spiders, slugs, snails, and worms, catching them with a sticky tongue. Tadpoles graze on algae and plant matter in their breeding pools.
Habitat and range
This frog ranges farther north than almost any other North American amphibian, reaching above the Arctic Circle. It lives in moist forests and woodlands and breeds explosively in temporary 'vernal' pools that dry up later in the year, which keeps fish from eating its eggs. It spends much of the year on land under leaf litter and logs.
Conservation
The wood frog is listed as Least Concern and remains widespread. Its main threats are the loss of the temporary woodland pools it needs to breed, along with pollution and forest clearing. Protecting these small seasonal wetlands is important for the species and for many other woodland amphibians.
Frequently asked questions about the Wood Frog
How do wood frogs survive winter?
Wood frogs can survive being frozen. Much of the water in their body turns to ice while their heart stops, protected by glucose that works like antifreeze. When it warms up in spring, they thaw and become active again.
What do wood frogs eat?
Adult wood frogs are insectivores that eat insects, spiders, slugs, snails, and worms, while tadpoles feed on algae and plant matter.
Where do wood frogs live?
Wood frogs live across northern North America in moist forests and woodlands, ranging farther north than nearly any other frog, even above the Arctic Circle.
How long do wood frogs live?
Wood frogs typically live about 3 years in the wild, though individuals in colder regions can live somewhat longer.
Why do wood frogs breed in temporary pools?
They breed in temporary 'vernal' pools that dry up later in the year. Because these pools have no fish, the frogs' eggs and tadpoles are safer from predators.
