Rana kauffeldi (Atlantic Coast leopard frog) Matthew D. Schlesinger

Rana kauffeldi (Atlantic Coast leopard frog)
Matthew D. Schlesinger

Class
Amphibia (Amphibians)
Family
Ranidae (True Frogs)
State Protection
Not Listed
Not listed or protected by New York State.
Federal Protection
Not Listed
State Conservation Status Rank
S1S2
Critically Imperiled or Imperiled in New York - Especially or very vulnerable to disappearing from New York due to rarity or other factors; typically 20 or fewer populations or locations in New York, very few individuals, very restricted range, few remaining acres (or miles of stream), and/or steep declines. More information is needed to assign either S1 or S2.
Global Conservation Status Rank
G3G4
Vulnerable globally, or Apparently Secure - At moderate risk of extinction, with relatively few populations or locations in the world, few individuals, and/or restricted range; or uncommon but not rare globally; may be rare in some parts of its range; possibly some cause for long-term concern due to declines or other factors. More information is needed to assign either G3 or G4.

Summary

Did you know?

The Atlantic Coast Leopard Frog is only one of two newly described frog species from the United States in the last 30 years.

State Ranking Justification

The Atlantic Coast leopard frog appears to have declined precipitously in New York, including vanishing from Long Island. A handful of populations remain in the lower Hudson Valley and on Staten Island.

Short-term Trends

Short-term trends are unknown. Despite considerable survey effort, leopard frogs have not been confirmed on Long Island since the mid-1990s, so major declines in that region are likely.

Long-term Trends

Over the long term, this species has been in precipitous decline, having disappeared from much of New York City and the Hudson Valley and all of Long Island.

Conservation and Management

Threats

Loss and fragmentation of wetlands, chytrid fungus (a fungus that has caused frog mortality nationwide), the expansion of bullfrogs, and invasion of wetlands by the common reed Phragmites are potential threats. No studies have been published that identify threats to populations of this species.

Conservation Strategies and Management Practices

Preservation of large wetlands and reduced use of pesticides are likely to help this frog. It is difficult to give specific management guidance because the species is newly discovered and only the basics of its distribution and ecology are known.

Research Needs

Research needs include investigation of spatiotemporal habitat partitioning and potential hybridization in areas of overlap with southern leopard frogs and to a lesser degree, northern leopard frogs. In addition, a description of the tadpole and egg mass of this species is needed. Research into causes of decline is needed as well.

Habitat

Habitat

In New York, leopard frogs occur primarily in open situations, including grasslands, wet meadows, grassy edges, shallow wetlands, and clear, slow-moving ditches. They may be found inland during the summer but in spring and fall they remain near water.

Range

New York State Distribution

The Atlantic Coast leopard frog is known definitively from four wetlands on Staten Island, two in Orange County, and one in Putnam County. Historically, it occupied much of New York City and Long Island as well as many more locations in the lower Hudson Valley.

Global Distribution

This species' global range has not been fully assessed but it appears to occupy a narrow stretch of the Atlantic coastal plain extending from northern North Carolina northward, up large river valleys in New York and Connecticut.

Identification Comments

General Description

Leopard frogs are green or brown, usually with irregularly spaced rounded dark spots on the back and a few dark spots on the sides of the body. A continuous usually yellowish ridge extends along each side of the back. The head is pointed, and sometimes there is a light spot in the center of the eardrum. The hind toes are extensively webbed. Maximum size is around 5.1 inches (13 cm) snout-vent length. Breeding males have vocal sacs at the angles of the jaw; the sacs are spherical when inflated. The forelimbs of mature males are more massive than those of females, and the base of the thumb is larger in males than in females. The breeding call is a repeated single chuck combined with an occasional drawn-out snore. Larvae have faint to dark mottling on the body and tail, and the eyes are positioned on top of head, not at the margin of the head, when viewed from above. Maximum size of larvae is about 3 inches (7.6 cm) in total length. Egg masses are baseball sized when the jelly is fully expanded and contain roughly 1,000-1,500 eggs.

Identifying Characteristics

A brown to green frog with rounded spots, distinct dorsolateral lines, and an occasional white spot on the tympanum. The reticulum (upper thighs) is typically dark with light spots. The call is a single-pulsed "chuck" with an occasional rolling "snore."

Characters Most Useful for Identification

The call is the only diagnostic feature of this species that has been identified to date.

Best Life Stage for Proper Identification

As the tadpole and egg mass have yet to be described, the adult stage is the only stage in which this frog can be distinguished from species. The call of the adult is diagnostic, but no 100% reliable visual field characters have been identified.

Behavior

Leopard frogs are primarily nocturnal. Males typically call between midnight and daybreak. They are very skittish and can make quick leaps into vegetation or water when they feel threatened. Egg masses of 3,000 to 5,000 eggs are often laid communally. Tadpoles hatch in 7-12 days and transform into adults in 2-3 months. Late-hatching eggs may overwinter as tadpoles. The frogs migrate between breeding pools and upland foraging areas. They hibernate in mucky bottoms of wetlands. (Gibbs et al. 2007)

Diet

Tapoles feed on algae, plant material, and organic debris while adult frogs feed on small invertebrates such as beetles, caterpillars, and spiders (Gibbs et al. 2007, Natureserve 2007).

  • Present
  • Active
  • Reproducing

The time of year you would expect to find Atlantic Coast Leopard Frog present, active, and reproducing in New York.

Similar Species

  • Pickerel Frog (Lithobates palustris)
    The pickerel frog has a yellow/tan wash on the underside of the legs and squarish as opposed to rounded spots. It may be cream or tan colored, which leopard frogs rarely are. Juvenile pickerels may be hardest to distinguish from leopards as their spots may look round and the leg color is less prominent.
  • Northern Leopard Frog (Lithobates pipiens)
    Northern leopard frogs never have a white spot on the tympanum, but rarely have a darker splotch. Their reticulums (upper thighs) are rarely dark with light spots.
  • Southern Leopard Frog (Lithobates sphenocephalus)
    Southern leopards have a more pointed snout and a more defined white spot on the tympanum, and usually have a light reticulum with dark spotting. These two species may not yet be reliably distinguishable in the field, except by call. Southern leopards have a rolling series of "chucks," as opposed to individual "chucks" by the Atlantic Coast leopard.
  • Wood Frog (Lithobates sylvaticus)
    These two are unmistakable visually, but the wood frog's call sounds much like the Atlantic Coast leopard's. However, the "chuck" sounds of the wood frog are multi-parted (three sounds quickly in succession) and there are no "snores."

Atlantic Coast Leopard Frog Images

Taxonomy

Atlantic Coast Leopard Frog
Lithobates kauffeldi Feinberg, Newman, Watkins-Colwell, Schlesinger, Zarate, Curry, Shaffer, and Burger, 2014

  • Kingdom Animalia
    • Phylum Craniata
      • Class Amphibia (Amphibians)
        • Order Anura (Frogs and Toads)
          • Family Ranidae (True Frogs)

Comments on the Classification

Newman et al. (2012) presented evidence that Lithobates kauffeldi is genetically distinct from both Lithobates sphenocephalus and Lithobates pipiens. In 2014 Feinberg et al. named it as Rana (= Lithobates) kauffeldi.

Additional Resources

References

Feinberg, J. A., C. E. Newman, G. J. Watkins-Colwell, M. D. Schlesinger, B. Zarate, B. R. Curry, H. B. Shaffer, and J. Burger. 2014. Cryptic diversity in Metropolis: Confirmation of a new leopard frog species (Anura: Ranidae) from New York City and surrounding Atlantic Coast regions. PloS one 9:e108213.

New York Natural Heritage Program. 2019. New York Natural Heritage Program Databases. Albany, NY.

Newman, C. E., J. A. Feinberg, L. J. Rissler, J. Burger, and H. B. Shaffer. 2012. A new species of leopard frog (Anura: Ranidae) from the urban northeastern US. Molecular Phylogenetics and Evolution 63:445-455.

About This Guide

This guide was authored by: Matthew D. Schlesinger

Information for this guide was last updated on: March 31, 2016

Please cite this page as:
New York Natural Heritage Program. 2019. Online Conservation Guide for Lithobates kauffeldi. Available from: https://guides.nynhp.org/atlantic-coast-leopard-frog/. Accessed September 19, 2019.

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