Lithobates kauffeldi (Feinberg, Newman, Watkins-Colwell, Schlesinger, Zarate, Curry, Shaffer & Burger, 2014)

Common Name & Base Coloration

Lithobates kauffeldi, commonly known as the Atlantic Coast leopard frog, has a body color that ranges from mint-gray to light olive green, with irregularly distributed brown spots across its back and legs.

Head & Limb Morphology

Dark stripes run along its head from the snout, it has large eyes, and strong legs built for leaping.

Color Change Patterns

Individuals' body color changes between day and night and across seasons: most individuals take on darker tones at night, and lighter hues during the day.

Male Vocal Sacs

Adult males have large vocal sacs on either side of the head, which they use to produce mating calls.

Interspecific Morphological Similarity

It is difficult to distinguish Atlantic Coast leopard frogs from Southern leopard frogs.

Distinguishing Morphological Traits

Key traits that set the Atlantic Coast leopard frog apart from the Southern leopard frog include no white spot on the tympanum, a femoral reticulum (inner thigh) that is mostly dark with unconnected light patches, a blunter snout, and duller overall coloration.

Morphological Trait Overlap

However, there is substantial overlap in these characteristics between the two species, and no single physical trait can reliably tell them apart.

Primary Distinguishing Feature

The most reliable distinguishing feature of the Atlantic Coast leopard frog is its mating call.

Mating Call Structure

The call of the Atlantic Coast leopard frog is a single, distinct "chuck" sound, unlike the repeated "ak-ak-ak" of the Southern leopard frog or the "snore" of the Northern leopard frog.

Geographic Range Extent

L. kauffeldi occurs in nine states along the northeastern coast of the United States, spanning from central Connecticut to northeastern North Carolina.

Range Dimensions

The species' north-south range is roughly 780 kilometers long, and extends about 100 kilometers inland from the Atlantic shoreline.

Southern Range Shape

The range narrows as it extends southward, and runs mostly along the I-95 corridor.

Local Extirpation

The species is thought to have been extirpated from most of Connecticut, the Hudson Valley, and Long Island.

Sympatric Congeners

The Atlantic Coast leopard frog lives alongside the northern leopard frog in Connecticut, and alongside the southern leopard frog from New Jersey through North Carolina.

Hybridization

It is known to hybridize with these two species where their ranges meet.

Historical Discovery Delay

For a long time, this species remained undiscovered because of its physical and habitat similarity to both the northern and southern leopard frog.

Habitat Variation Across Range

The Atlantic Coast leopard frog uses different habitats across the extent of its range.

Northern Range Habitat

In the northern part of its range, from Delaware through Connecticut, it tends to live in large coastal or riparian wetlands, such as marshes and wet meadows.

Northern Habitat Characteristics

These habitats typically contain clear, shallow water, and the species is commonly associated with plants including Phragmites australis, cattails, and river shrubs.

Southern Range Habitat

In Virginia and North Carolina, it primarily lives in riparian cypress-gum swamps.

Habitat Specificity

Compared to the sympatric Southern leopard frog, which uses a wider variety of habitats, the Atlantic Coast leopard frog is a habitat specialist.

Urban Habitat Use

Across its range, the Atlantic Coast leopard frog also occupies fragmented wetland habitats in many urban areas, including Staten Island, the New Jersey Meadowlands, Philadelphia, and the Wilmington-New Castle area of Delaware.