Ranidae
Rana areolata, Crawfish Frog
This frog gets
its common name because of its tendency to hide in crayfish
burrows. It gets
its specific epithet (arealata) from the light border
around each dorsal spot (areola). The large dorsal spots are
numerous and there are small dark markings between them. The frog
is short and fat with a blunt snout. The legs are
proportionately shorter than in other ranids and
in females
the dorsolateral
folds seem to blend into the
background.
In males the
folds are yellow and yellow is also present on the inner surface
of the legs. Iowa's other spotted ranids all have a more elongated
appearance, more pointed snout and lack dark markings
between the spots. Unlike
species of the leopard frog complex, there is no light
line on the upper lip. Crawfish frogs grow even larger than
members of the Rana pipiens group attaining lengths
of up to 4 1/2 inches (114 mm). The northern crawfish
frog, Rana areolata circulosa, is the only
subspecies found
in Iowa.
Crawfish frogs call about mid-April in Iowa, often during rains. They make a deep pig-like snore, often interspersed with a chuckle. They utilize abandoned holes as refuges, including those made by crayfish. The tadpoles overwinter and transform in their second year. This frog was found in several places in southeastern Iowa (Appanoose, Davis, Jefferson, Van Buren and Wayne counties) in the early 1940s but we have been unable to find a single frog in recent years, even from visits to the same localities. The species is listed as endangered in Iowa.