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Upper Midwest Environmental Sciences Center

Farm ponds as critical habitats for native amphibians
A Field Guide to Amphibian Larvae and Eggs of Minnesota, Wisconsin, and Iowa
Field guide contents

Leopard, Pickerel, and Crawfish Frogs

Northern Leopard Frog Rana pipiens
Southern Leopard Frog Rana sphenocephala
Plains Leopard Frog Rana blairi
Pickerel Frog Rana palustris
Crawfish Frog Rana areolata

Status: R. pipiens – Common in Wisconsin, Minnesota and Iowa
R. sphenocephala – Uncommon and declining in Iowa
R. blairi – Locally abundant but declining in Iowa
R. palustris – Special Concern in Wisconsin,
uncommon in Iowa and Minnesota
R. areolata – Extirpated in Iowa (?)
Northern Leopard Frog tadpole
(Northern Leopard Frog tadpole) 4.5 - 8.5 cm total length
field map
R. pipiens
field map
R. blairi
field map
R. sphenocephala
field map
R. palustris
field map
R. areolata
 

We group the eggs and larvae of the ranid species above together in this account. Geography and observation of adults may be necessary to help with identification. Southern Leopard Frogs are incidental in extreme southeastern Iowa and the Crawfish Frog has not been seen in extreme southern Iowa in over 60 years (Christiansen 1998). The eggs of these species are laid in globular masses attached to vegetation or on the bottom in shallow water. The Northern Leopard Frog and Pickerel Frog can be distinguished from each other because the Northern Leopard Frog has eggs that are black on one side and white on the other, whereas the Pickerel Frog has eggs that are brown on one side and yellowish on the other. The tadpoles are greenish or brownish with dorsal eyes and mottling on the tail. The intestinal coil is at least partly visible through the skin on the belly. Pickerel Frog tadpoles have been described as green or olive green with large dark blotches on their tail musculature and fins. Leopard Frogs are green or yellowish green without the large dark blotches.

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URL: http://www.umesc.usgs.gov/terrestrial/amphibians/field_guide/leopard_pickerel_crawfish frogs.html
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Page Last Modified: December 29, 2010