Northern Leopard FrogLithobates pipiensWhere and when to see them

The Northern Leopard Frog is a spotted, semi-aquatic frog native to much of Canada and the northern and central United States. Along the Mississippi, it is most characteristic of the upper river basin and nearby wetlands rather than the entire river corridor. Its life cycle connects shallow breeding waters, grassy summer feeding areas, and aquatic overwintering sites. It serves as both a predator of small animals and prey for fish, birds, snakes, and mammals. Although globally assessed as Least Concern, it faces regional pressures from wetland loss, pollution, disease, and introduced predators.

Size

Adults usually measure 5–11 cm (2–4.3 in) from snout to vent; females are generally larger than males.

Weight

Adults typically weigh about 16–80 g (0.6–2.8 oz), depending on size and condition.

Lifespan

Typically 2–4 years in the wild.

Status

Least Concern (IUCN); some regional populations have declined.

Northern Leopard Frogs divide their active season between water and nearby terrestrial habitats. In warm weather, they often forage in damp grasslands and wet meadows, sometimes well away from permanent water. They may be active by day or night, depending on temperature and moisture. When startled, they escape with powerful leaps and often dive into nearby water. During spring breeding, males give low, snore-like calls interspersed with grunts or chuckles. Females attach rounded egg masses to submerged vegetation in shallow water, and the tadpoles usually transform into frogs during summer. In winter, adults shelter underwater in sufficiently oxygenated ponds, lakes, or streams, absorbing oxygen through their skin.

• Its species name, pipiens, refers to its voice.
• Its breeding call sounds more like a low snore than a classic croak.
• It can absorb oxygen through its skin while overwintering underwater.
• A single frog may use different wetlands for breeding and winter shelter.

Wildlife opportunities depend on the river reach, water levels and species. River-specific viewing months have not been confirmed; general species seasons are not a local sighting forecast.

This frog uses a mosaic of freshwater wetlands and open, moist terrestrial habitats. Breeding sites include shallow ponds, marshes, and quiet pools with aquatic vegetation, often with few or no predatory fish. Summer habitat includes wet meadows, grassy shorelines, and floodplain wetlands. Along the Upper Mississippi, suitable places may occur around backwaters, sloughs, and adjoining marshes rather than in the fast-flowing main channel. Overwintering requires water that remains unfrozen at depth and contains enough dissolved oxygen.

Adults eat a wide variety of small animals, especially insects and other invertebrates. Common prey include beetles, flies, crickets, spiders, and worms. Larger frogs occasionally take small vertebrates, including other frogs. Tadpoles mainly graze on algae and consume plant material, organic debris, and associated microorganisms.

Common name

Northern Leopard Frog

Scientific name

Lithobates pipiens

Animal group

Amphibians

Size

Adults usually measure 5–11 cm (2–4.3 in) from snout to vent; females are generally larger than males.

Weight

Adults typically weigh about 16–80 g (0.6–2.8 oz), depending on size and condition.

Lifespan

Typically 2–4 years in the wild.

Status

Least Concern (IUCN); some regional populations have declined.

Identification

Look for a green, olive, or brown frog with dark, rounded spots bordered by pale halos. Two conspicuous pale dorsolateral ridges run along the back from behind the eyes toward the groin. The belly is usually white or cream, and the hind legs have dark bars. Several leopard frog species resemble one another, particularly farther south in the Mississippi basin, so consider location, calls, and multiple field marks rather than color alone.