Description: The northern leopard frog is a fairly large species of frog, reaching about 4.3 inches in snout-to-vent length. It varies from green to brown in dorsal color, with large, dark, circular spots on its back, sides, and legs. Each spot is normally bordered by a lighter ring. A pair of dorsolateral folds starting from the back of the eye runs parallel to each other down the back. These dorsolateral folds are often lighter or occasionally pinkish in colour. Also, a pale stripe runs from the nostril, under the eye and tympanum, terminating at the shoulder. The ventral surface is white or pale green. The iris is golden and toes are webbed. Tadpoles are dark brown or grey, with light blotches on the underside. The tail is pale tan.

The northern leopard frog has several different color variations, with the most common two being the green and the brown morphs, with another morph known as the burnsi morph. Individuals with the burnsi morph coloration lack spots on their backs, but may or may not retain them on their legs. They can be bright green or brown and have yellow dorsal folds. Albinism also appears in this species, but is very rare.

Habitat: Northern leopard frogs have a wide range of habitats. They are found in permanent ponds, swamps, marshes, and slow-moving streams throughout forest, open, and urban areas. They normally inhabit water bodies with abundant aquatic vegetation. In the summer, they often abandon ponds and move to grassy areas and lawns. They are well adapted to cold and can be found above 9,800 feet above mean sea level.

Range: Northern leopard frogs occur from Great Slave Lake and Hudson Bay, Canada, south to Kentucky and New Mexico, USA. It is also found in Panama, where it is endemic to the central cordillera and western Pacific lowlands, although this is most likely an undescribed species.[

Found in these States: AZ | CA | CT | IA | IL | IN | KY | MA | MD | ME | MI | MN | MO | MT | ND | NE | NH | NJ | NM | NV | NY | OH | OR | PA | RI | SD | UT | VT | WA | WV | WY

Diet: They eat a wide variety of animals, including crickets, flies, worms, and smaller frogs. Using their large mouths, they can even swallow birds and garter snakes.

Reproduction: Males make a short, snore-like call from water during spring and summer. The northern leopard frog breeds in the spring (March–June). Up to 6500 eggs are laid in water, and tadpoles complete development within the breeding pond. Tadpoles are light brown with black spots, and development takes 70–110 days, depending on conditions. Metamorph frogs are 0.79–1.18 inches long and resemble the adult.

Status: This species was once quite common through parts of western Canada and the United States until declines started occurring during the 1970s. Although the definitive cause of this decline is unknown, habitat loss and fragmentation, environmental contaminants, introduced fish, drought, and disease have been proposed as mechanisms of decline and are likely preventing species' recovery in many areas. Many populations of northern leopard frogs have not yet recovered from these declines.

Subspecies: None

Taxonomy: This species was placed in the genus Lithobates by Frost et al. (2006). However, Yuan et al. (2016, Systematic Biology, doi: 10.1093/sysbio/syw055) showed that this action created problems of paraphyly in other genera. Yuan et al. (2016) recognized subgenera within Rana for the major traditional species groups, with Lithobates used as the subgenus for the Rana palmipes group. AmphibiaWeb recommends the optional use of these subgenera to refer to these major species groups, with names written as Rana (Aquarana) catesbeiana, for example.