Lithobates pipiens,
formerly Rana pipiens
Northern Leopard Frog / Grenouille Léopard
Description
A green or brown frog with large, light-edged spots. Northern Leopard Frogs also
have prominent light-coloured
dorsolateral ridges and a white belly. They can grow to over 10 cm body length
but this is quite rare. Adults are usually 5-8 cm.
Call
The male's
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. It is similar to the
call of the Pickerel Frog but more complex.
Confusing Species
In eastern Canada the Northern Leopard Frog is most similar to the
Pickerel Frog. The Pickerel Frog has more
squarish spots, a yellow belly and is always brown. In western Canada there are no
other large frogs with large spots.
Distribution
The Northern Leopard Frog is found in every province and territory with the exception
of the Yukon. It is found in only southeastern British Columbia and the southern
portions of the Northwest Territories. Northern Leopard Frogs occur across most of
central and eastern Canada. They are native to Labrador, and are introduced on the
island of Newfoundland. They are also found through much of the northern United States.
Habitat
Northern Leopard Frogs occupy a wide range of habitats from prairie to woodland to tundra.
They are often found a considerable distance from open water.
Reproduction
Breeding occurs in mid-late spring in relatively permanent ponds without fish. Egg
masses are attached to submerged vegetation. A female can lay up to 7000 eggs although
half this number is more typical. The eggs are approximately 1.5 mm in diameter and
hatch in one to three weeks depending upon the temperature. Tadpoles transform in mid
to late summer.
Natural History
The Northern Northern Leopard Frog is part of a large complex of closely related species
that range across all of North America. Only the Northern Leopard Frog is found in Canada.
Northern Leopard Frogs eat a wide variety of prey, but mainly insects, spiders and other
small invertebrates. They are eaten by snakes, turtles, herons and raccoons, to name but a
few predators. Winters are spent on the bottom of waterbodies that do not freeze solid.
In many areas Northern Leopard Frogs hibernate in different ponds from where they breed.
It takes a Northern Leopard Frog approximately two years to reach maturity. In captivity,
they have lived for up to nine years although individuals in the wild would likely only
live to age three or four.
Conservation Concerns
In western Canada Northern Leopard Frogs have dramatically declined over the last few
decades. They virtually disappeared from Manitoba in the late 1970s and large declines
have also been reported from Alberta.There is some evidence that they have also declined
in northern Ontario.Populations appear to have stabilized and in some instances
increased.Although the cause of the decline has not been confirmed, possible causes
are long-term drought and habitat loss. The Northern Leopard Frog is designated
Endangered in British Columbia, Special Concern in the north and the prairies
(Northwest Territories, Alberta, Saskatchewan, Manitoba) and not at risk in eastern
Canada by COSEWIC.
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