A small brown frog with a distinctive black "robber's mask" — the most widespread frog in North America and the only one that lives north of the Arctic Circle.
§ Quick facts
§ Encyclopedia
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, interesting habitat associations, and relatively long-range movements. It is the only North American frog that occurs north of the Arctic Circle.
Source: Wikipedia — Wood frog Licensed under CC BY-SA 4.0
§ Identification
Field marks. Small to medium frog with reddish or tan-brown body; distinctive dark "robber's mask" behind eye; pale belly.
Similar species. Northern Leopard Frog (spotted). Pickerel Frog (square spots). Green Frog (no mask).
Voice. Soft quacking calls — chorus sounds like distant duck flock.
§ Diet & behavior
Diet. Small insects, spiders, slugs, snails.
Behavior. Northernmost-distributed amphibian in North America — found above the Arctic Circle. Survives Alaskan winters frozen solid: ice fills the body cavity, brain stops, heart stops; blood and cells protected from freeze damage by high concentrations of glucose and urea. Thaws over hours in spring with normal function restored. Explosively-breeding species — entire local population may breed in a single warm spring night.
§ Range
Northern North America from Alaska to Labrador, south to Tennessee
§ Habitat
Forested ponds, vernal pools, moist deciduous and mixed woodlands
§ Threats
Vernal pool loss, road mortality during breeding migrations, climate disruption to freeze-thaw cycles, ranavirus disease.
§ Conservation status
According to the IUCN Red List, the wood frog is currently classified as Least Concern.
§ What helps
Protect vernal pools. Don't move frogs between regions (disease spread). Support wetland-buffer ordinances.
§ Further reading
- Wikipedia — Wood frog
- www.nwf.org — authoritative profile of Lithobates sylvaticus
- IUCN Red List · taxon 58728
- iNaturalist · taxon 66318
- GBIF occurrence records
- Encyclopedia of Life — Lithobates sylvaticus
§ Sources cited
- AmphibiaWeb
- USGS PWRC
- University of Alaska Fairbanks Institute of Arctic Biology
- IUCN Red List 2014
