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Northern Leopard Frog

Lithobates pipiens

Family: Ranidae

Until recently, the Northern Leopard Frog was in the genus Rana, but it is now in the genus Lithobates.

COSEWIC status:
  • Not at Risk (Eastern population)
  • Endangered (Rocky Mountain population)
  • Special Concern (Western Boreal/Prairie population)
SARA status:
  • No Status (Eastern population)
  • Endangered (Rocky Mountain population)
  • Special Concern (Western Boreal/Prairie population)
IUCN status:
  • Least Concern


The Northern Leopard Frog is a medium to large frog that can grow to 11 cm in body length. Individuals are green or brown with dark oval spots on the head, back and sides and dark bars on the legs. Northern Leopard Frogs have prominent, light-coloured dorsolateral folds (folds of skin running down each side of the back), a whitish upper lip and a white belly that occasionally has a yellowish tinge. Larvae (tadpoles) have long tails, a large fin tail fin that is usually lighter than the belly and lack front legs (newly hatched tadpoles are legless). The larvae range from light to dark brown or green with small, gold spots and bronze bellies. The larvae can reach 12 cm in length, but most metamorphose when they are around 9 cm in length. The call is a low snore followed by several low grunts and does not carry very far. Sometimes it sounds like a finger rubbed on a wet balloon.

Similar Species

The Northern Leopard and Pickerel Frog are similar in appearance, but the Pickerel Frog is always brown with rectangular spots. The spots of the Pickerel Frog are typically arranged in two rows along the back while the spots of the Northern Leopard Frog tend to be random. The Pickerel Frog also has yellow to orange colouration on the thighs and groin.


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The Northern Leopard Frog has an extremely large Canadian range and is found in every province and a small part of the Northwest Territories. This species also has an extensive range across the northern half of the United States, with some populations occurring as far south as western Texas.


Northern Leopard Frogs breed in permanent or semi-permanent wetlands, streams and shallow sections of lakes and rivers that have clear water and are typically free of predatory fish. Individuals forage extensively in terrestrial habitats during the summer and are often found considerable distances from aquatic habitats in fields, woodlands and meadows. These frogs hibernate at the bottom of lakes and large ponds.


Northern Leopard Frogs hibernate during the winter and are typically active from April until October in southern Canada, but the active season is shorter further north. Males call to attract females during the breeding season, which occurs over a short period in the spring. During breeding, the male grasps the female (amplexus) and fertilization occurs externally in aquatic habitats as the female lays eggs. The female lays a globular mass of 500–5000 eggs that is 6–9 cm in diameter. The eggs mass is usually attached to aquatic vegetation near the surface of the water and within a few metres of shore. The eggs are black on top and white underneath and are surrounded by two clear jelly envelopes. The eggs hatch in one to three weeks, depending upon the water temperature, and the tadpoles metamorphose into frogs two to three months later. Individuals reach maturity after two to three years and most probably do not live for more than five years. Northern Leopard Frogs eat a wide variety of invertebrates, such as spiders, worms, isopods, beetles, crickets, grasshoppers, ants, and flies. Northern Leopard frogs may migrate up to 2 km from their hibernation site to their breeding sites.


The Northern Leopard Frog is widespread and abundant throughout eastern Canada, but it declined dramatically in the western part of its range in the 1970s and remains rare in western Canada. Habitat loss and fragmentation is a significant threat to Northern Leopard Frog populations in southern Canada, and especially in the limited distribution of the Rocky Mountain Population, where much of the landscape has been converted to intensive agriculture and urban uses. Northern leopard frogs also appear to be especially susceptible to chemical pollutants, such as herbicides and pesticides, resulting in high incidences of Northern Leopard Frogs with severe malformations (e.g., extra limbs). Large numbers of Northern Leopard Frogs are killed on roads every year during migrations to and from breeding sites, and high levels of road mortality can cause long-term decline of frog populations. The introduction of predatory sport fish into breeding habitats can be detrimental to Northern Leopard Frog populations. Pathogens such as chytrid fungus and Ranavirus can cause mass mortality of frog populations. Climate change may also pose future threats to Canada’s frog populations

Additional Information About This Species In Canada