Rana sylvatica
Rana sylvatica
The Wood Frog is a common
frog found near water, or far from water, in the woods. It
grows to about three inches long. Its color ranges from
pinkish-brown to tan to dark brown. The Wood Frog is most
easily recognized by its "robber mask." This black band
stretches past both eyes to the eardrums. Wood Frogs also have
dorsolateral ridges, two raised lines running down their
back. This frog has a white
belly.
Because Wood Frogs spend a lot of time on land, the toes on their front legs are not fully webbed. You can tell males from females by their swollen thumbs.
Wood Frogs are one of the first frogs to breed in early Spring. Their calls, which sound like a "quack," can be heard around water that's near woods. After breeding, these frogs leave the water to go off into the woods. They will return the following Spring.
|
J. Harding |
To mate, males call females from the water. When a male sees another frog, he hugs it (called "amplexus" with frogs). Unfortunately, he can't tell a male from a female until he does. Once he hugs the other frog, he can feel if she is fat with eggs, or if he's grabbed another male. If he grabbed a male, that male will croak loudly, and this will make the first frog let go. When the frogs have mated, the female will lay a large egg mass, holding over 1000 eggs into the water. Usually, she attaches it to some sticks or stems of a plant. |
J.Harding
Wood Frogs all mate in
the same area, so all the eggs are next to each other making
a large "egg matt" on the surface of the water. This matt
will grow algae
on it, and soon be disguised as pond slime. Eggs will hatch into
small brownish-black tadpoles.
Tadpoles take about two months to become adult
frogs. They eat algae after they hatch, before moving on to
small insect larvae. Adults travel quite far
from the water during Summer. They are most active during
the day, but they are protected by their coloring, which
camouflages
them. In winter, Wood Frogs
hibernate
by hiding under rocks, stumps, or leaf
litter. They
don't have to dig far. If they freeze, they can thaw out
again. Copyright,
Walter Knapp
Copyright, Jeff LeClere
Wood Frogs are very active, and can jump farther than most frogs. To hunt, they can ambush prey, like most frogs, or sneak up on it.
Wood Frogs eat beetles, flies, caterpillars, and other insects; and also spiders, other arthropods, slugs, snails, and worms.
Predators of Wood Frog eggs and tadpoles include leeches, fish, and aquatic insects. Adults are eaten by raccoons, owls, and other animals.
Relationships in Nature:
Relationship to Humans:
Wood Frogs, like all frogs, eat huge amounts of insects. This helps control them. The calls of Wood Frogs also help us know that Spring is coming.
