Print | Bookmark

Northern Leopard Frog

Rana pipiens Schreber

Northern Leopard Frogs, also called meadow or grass frogs, are bright grass-green with oval black spots. They spend a lot of time foraging in grassy places during the summer. You may see them in old fields, meadows, grassy-sedge woods roads and grassy roadside ditches. Juveniles are often seen resting on sphagnum moss at the edge of roadside ponds.

Leopard Frogs emerge from underwater hibernation in spring. From mid-April to mid-May the males rest, with limbs spread out, on the surface in the shallows of ponds and vegetated coves of lakes. Their breeding call is a long rattling snore followed by several rapid grunts. Females lay about 3000 eggs in a loose oval mass in shallow water. Newly hatched tadpoles stay in a close group for some time. The tadpoles develop rapidly and change to frogs during July and August.

Leopard Frogs eat many insects and other invertebrates. Since they spend so much time in grassy places, they eat a lot of agricultural pest insects. Juveniles eat aquatic insects.

Adults return to aquatic habitats during the autumn to hibernate.

Additional Facts and Details

The family Ranidae of typical frogs consists of 45 genera and 586 species and is distributed nearly worldwide.

The genus Rana is represented in the Maritimes by 6 species in New Brunswick and Nova Scotia, while 3 occur on Prince Edward Island.

The toes on the front legs are unwebbed.

Breeding males can be told from females by the swollen base of the thumbs on the forelegs. This is related to the tight holding they do during amplexus.

Rarely, a Leopard Frog is found which is partly blue instead of green. The green frog colour is a combination of structural blue and a yellow pigment; if the yellow is absent, the blue shows brightly.

The total number of spots on the back ranges from 8 to 23.

Size: body length of 13 newly transformed young ranged from 2.4 to 2.6 cm. Adult males, 74 measured, from 5.7 to 7.8 cm. Adult females, 44 measured, from 6.6 to 9.5 cm.

The dorsolateral folds are prominent and extend the length of the trunk. There are usually two, sometimes four smaller dorsal folds between them.

Distribution in Canada: Maritime Provinces, most of Quebec and Ontario and across the Prairies to the Rocky Mountains. Also occurs in the southern valleys of the central and eastern regions of British Columbia. North to Fort Smith in the Northwest Territories.

In the United States, south to Pennsylvania and Kentucky, west to Nevada, Arizona and New Mexico.

In Nova Scotia, Leopard Frogs are widespread on the mainland and Cape Breton Island.

Earliest spring record is March 27, in 1973, when an adult male was found on a wet highway at Danesville, Queens County.

Latest fall date is November 5, 1982, a freshly-killed adult found on the road in the Forties Settlement area, Lunenburg County.