Rana pipiens
(Northern Leopard Frog)

Key Characteristics:

Adult Characteristics	Tadpole Characteristics	Egg Characteristics
Prominent dorsolateral folds	Brown with metallic flecks	Pigmented
Dark blotches with light halos	Eyes set in from margin of head	Flattened spherical clusters
White ventral coloration	Intestines visible	.
Males call	Tail fin translucent	.

General Description:
Northern Leopard Frogs are medium sized reaching sizes up to 100mm (4 in.).  They are easily recognized by the dark spots that are surrounded by light colored halos.  Their ground color is usually some shade of green or brown.  Northern Leopard Frogs have a white ventral coloration.  Additional distinguishing characteristics are the prominent dorsolateral ridges found running from behind the eye to the groin and the readily visible tympanum.  Males will congregate and produce a chorus described as a guttural chuckling.  The males will actually produce three distinct calls with varying sounds (see Nussbaum et al. 1983).

Northern Leopard Frog tadpoles are similar, although smaller, than Bullfrog tadpoles, reaching sizes of around 85mm (3.3 in.).   Northern Leopard Frogs tadpoles lack the black specks of Bullfrog tadpoles, having metallic flecks on a brown dorsal color instead.  Ventrally, Northern Leopard Frog tadpoles are translucent with the intestines readily visible.

Northern Leopard Frog eggs are small (1.5mm or 1/25 in.) in diameter and are laid in flattened spherical clusters.  Each clutch can contain up to 6,000 eggs.  Multiple females may lay clutches in the same area as evidenced by the photo.

Idaho Distribution:
In Idaho, Northern Leopard Frogs are found throughout much of the southern part of the state, following the Snake River Plain.  Populations also exist in the northern portion of the panhandle.

From Great Slave Lake and Hudson Bay, Canada, south to Kentucky and New Mexico. Introduced in number of localities in western states.

Habitat:
Northern Leopard Frogs are generally associated with heavily vegetated marshes, ponds, streams etc.  Likewise, they seem to breed in areas that are also heavily vegetated.  In Idaho, they may be found in or around ponds, lakes and marshes

Diet:
Metamorphosed frogs eat various small invertebrates obtained along water's edge or in nearby meadows or fields. Adults rarely eat small vertebrates, although in Idaho, northern leopard frogs are known to eat birds, garter snakes, tadpoles, small frogs, and fishes, as well as snails, leeches, spiders and small insects. Larvae eat algae, plant tissue, organic debris, and probably some small invertebrates.

Ecology:
Probably hibernates in streams, ponds or other aquatic locations in winter. Disperses to moist uplands or permanent water during dry-up in summer. Requires moderately high ground cover for concealment. Preyed upon by garter snakes. When disturbed, these frogs leap rapidly and erratically. Anecdotal information exists for their decline in Idaho.

Reproduction:
Lays clutch of up to several thousand eggs from March to June, depending on range (in Idaho, breeding activity begins in March or April, when water temperatures reach 10° C). Aquatic larvae usually metamorphose in summer, but may overwinter in some areas. In most areas, adults reach sexual maturity in 2 yr.

Conservation:

Status:	Unprotected nongame species
Global Rank:	G5
State Rank:	S3

Important State Reference:
Groves, C.R. and C. Peterson. 1992. Distribution and population trends of Idaho amphibians as determined by mail questionnaire. Idaho Dept. Fish & Game, Boise. 16pp.