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Leopard frog

Leopard frogs are a group of medium-sized, smooth-skinned true frogs in the genus Lithobates (family Ranidae), native to North and Central America, characterized by their green, brown, or yellow-green dorsal coloration marked with large, oval dark spots surrounded by light borders or halos, along with prominent dorsolateral folds and often a white stripe along the upper jaw.^[1] The northern leopard frog (Lithobates pipiens), one of the most widespread and commonly studied species also known simply as the leopard frog, typically measures 2 to 4.5 inches (5 to 11 cm) in length and weighs 0.5 to 2.82 ounces (16 to 80 g), with males developing swollen thumbs during the breeding season.^[1] These frogs have slender bodies, long hind legs adapted for jumping, and webbed feet suited for swimming.^[1]^[2] The northern leopard frog is native to much of North America, inhabiting a variety of wetland environments, including permanent pools, slow-moving streams, marshes, and fishless ponds, where it breeds in shallow, vegetated waters during spring.^[1] During summer, individuals often venture into adjacent wet meadows, grasslands, or forest edges, sometimes traveling up to 2 miles from water, while they hibernate overwinter in oxygen-rich, non-freezing aquatic sites such as lake bottoms.^[1]^[2] Its historical range spans from Newfoundland and Labrador across the United States to Arizona and Mexico, and northward into Canada from southeastern British Columbia to the Atlantic coast, though populations have become fragmented and declined in the western U.S. and Canada since the mid-20th century.^[1]^[3] As opportunistic predators, adult northern leopard frogs primarily consume insects, spiders, and other invertebrates, but they also prey on small vertebrates such as fish, birds, snakes, and fellow amphibians, while tadpoles feed herbivorously on algae and plant matter.^[1] Breeding occurs from April to May in non-acidic waters, with females laying large gelatinous egg masses containing thousands of eggs (often over 6,000) attached to submerged vegetation; eggs hatch within 2 to 17 days, and tadpoles metamorphose into froglets after 3 to 6 months, reaching sexual maturity at 1 to 3 years of age.^[1]^[2] The species' distinctive call—a long, snoring "rrrrrr" followed by "chuck-chuck-chuck"—serves as a key identifier during the mating season.^[2] The northern leopard frog plays a significant ecological role as both predator and prey in aquatic and terrestrial food webs, serving as an indicator of wetland health due to its sensitivity to environmental changes.^[1] It has been widely used as a model organism in biomedical research, including studies in cancer, neurology, physiology, and biomechanics, owing to its ease of maintenance in laboratories.^[4] However, populations have experienced sharp declines since the 1960s, attributed to habitat loss, pollution, pesticides, introduced predators, and diseases like red-leg syndrome. Although not listed as threatened or endangered under the U.S. Endangered Species Act as of the 2011 U.S. Fish and Wildlife Service review (with no federal change as of 2025), it is considered endangered in some regional populations, such as the Rocky Mountain distinct population segment in Canada under the Species at Risk Act and in the Northwest Territories (assessed May 2025), and is a species of special concern in several U.S. states.^[1]^[2]^[5]^[6] Conservation efforts, including habitat restoration, monitoring, and captive breeding programs (e.g., at the Oregon Zoo), focus on supporting recovery in affected regions.^[1]^[7]

Description

Physical characteristics

Leopard frogs, belonging to the genus Lithobates, are medium-sized true frogs typically measuring 2 to 4 inches (5 to 10 cm) in snout-vent length for adults, excluding the hind legs.^[8] They possess a slim body with a pointed snout and smooth, moist skin that facilitates cutaneous respiration through high permeability for gas and water exchange.^[1] This skin texture is essential for maintaining hydration and thermoregulation in their environments.^[1] The dorsal coloration of leopard frogs ranges from bright green to olive or brown, overlaid with distinctive dark, rounded or oval spots scattered across the back and sides, often bordered by lighter yellow or white edges that evoke a leopard-like pattern.^[1] These spots vary slightly in arrangement among species but are a hallmark of the genus.^[9] Raised dorsolateral folds, pale yellow or tan ridges running along the length of the back from behind the eyes to the groin, provide structural support and are prominent in all species.^[9] Leopard frogs feature long, powerful hind legs adapted for jumping distances up to 10 times their body length, paired with shorter forelegs and fully webbed hind feet that aid in swimming.^[10] The ventral surface is white or cream-colored, occasionally marked with small dark spots, while a prominent tympanum, the external eardrum, is visible behind each eye and is notably larger in males.^[1] Males also exhibit an inflatable throat or paired vocal sacs during calling, though the exact configuration can vary across species.^[8]

Variations among species

The northern leopard frog (Lithobates pipiens) exhibits distinct morphological traits that set it apart from other species in the genus, including large, oval dark spots on its dorsal surface, often bordered by a light halo or white rim, against a more uniform green or brown background.^[1] These spots are typically prominent and can exceed the diameter of the eye, contributing to its identification in northern habitats.^[11] In contrast, the southern leopard frog (L. sphenocephalus) displays smaller, more irregular dark spots that are rounded and less distinctly bordered, often appearing on a greenish-brown to tan background with a subtle yellowish tint along the jawline and ridges.^[12] Its body proportions include relatively shorter hind legs compared to the northern species, giving it a stockier appearance overall.^[13] The Rio Grande leopard frog (L. berlandieri) is characterized by a brighter pale green to olive dorsal coloration with bold, numerous black spots that lack clear light edging, paired with a more robust build suited to its warmer range.^[14]^[15] Distinctive among southwestern species, the Chiricahua leopard frog (L. chiricahuensis) features small, raised cream-colored spots on the thighs set against a dark background, accompanied by a rougher skin texture and overall olive to dark green hue with smaller dorsal spots.^[16]^[17] The lowland leopard frog (L. yavapaiensis) shows pale tan to light green coloration with fine, irregular dark spotting lacking light halos, and a smaller body size—typically up to 8.7 cm snout-vent length—adapted to arid lowland environments.^[18]^[19]^[20] Finally, the Atlantic Coast leopard frog (L. kauffeldi) closely resembles the northern species but has subtler, smaller dark spots on a drab olive-green to brown background, with distinct throat features including large external vocal sacs in males that aid in its unique calling.^[21]^[22]

Habitat and distribution

Geographic range

Leopard frogs, belonging to the genus Lithobates, are native to North America, with their collective range extending from southern Canada, including the Hudson Bay region, southward through the United States to central Mexico.^[8]^[23] The northern leopard frog (Lithobates pipiens) has the broadest distribution among the group, occurring widely across northern and central regions of the United States and Canada, from Labrador in the east and southeastern British Columbia in the west southward to New England, Kentucky, Nebraska, New Mexico, and Arizona, and extending west to Washington and Oregon.^[23]^[8]^[24] In contrast, the southern leopard frog (Lithobates sphenocephalus) is primarily found in the eastern and central United States, ranging from southern New York and New Jersey southward through the Coastal Plain to Florida and westward to eastern Kansas, central Oklahoma, and eastern Texas, generally avoiding the extreme northern latitudes.^[25]^[26] The Rio Grande leopard frog (Lithobates berlandieri) occupies southwestern portions of the United States, including Texas and New Mexico, and extends into northeastern Mexico as far south as Veracruz.^[27] Species with more restricted distributions include the Chiricahua leopard frog (Lithobates chiricahuensis), which is limited to central and eastern Arizona, western New Mexico, and north-central Sonora in northern Mexico, and the lowland leopard frog (Lithobates yavapaiensis), confined to central Arizona below the Mogollon Rim, southeastern California (though largely extirpated there), and adjacent areas in Sonora, Mexico.^[28]^[29]^[30]^[20] The Atlantic Coast leopard frog (Lithobates kauffeldi) is endemic to coastal areas of the eastern United States, distributed from New York southward to Virginia, including sites in Connecticut, New Jersey, Pennsylvania, Delaware, Maryland, and North Carolina, with records from urban environments such as Staten Island near Yankee Stadium in New York City.^[31]^[32]^[33] Western populations of several leopard frog species, particularly the northern and lowland forms, have experienced significant range contractions compared to their historical extents, with extirpations reported from up to 95% of former habitats in states like California, Oregon, Washington, and Texas due to various environmental pressures.^[34]^[24]^[35]

Preferred habitats

Leopard frogs primarily occupy aquatic and semi-aquatic environments, favoring permanent or temporary wetlands, marshes, ponds, slow-moving streams, and lake edges with emergent vegetation such as sedges and rushes for cover and breeding.^[1]^[34] They exhibit a strong preference for open, sunny areas featuring shallow water depths of 4 to 26 inches for breeding sites, which lack predaceous fish and acidity, alongside adjacent grassy uplands or wet meadows for summer foraging.^[1] Certain species, including the southern leopard frog, also tolerate slightly brackish water in coastal marshes and floodplains.^[36] During colder months, leopard frogs overwinter by burrowing into mud at pond bottoms or retreating to deeper, well-oxygenated water bodies in streams, rivers, or lakes to avoid freezing and hypoxia.^[1]^[34] Their habitat use relies on interconnected landscapes, where breeding wetlands connect via vegetated corridors—such as drainage ditches or field edges—to summer foraging grounds in grasslands or meadows, facilitating dispersal distances up to 2 miles (3.2 km).^[1]^[37]^[34] The frogs' permeable skin demands persistently moist conditions for osmoregulation and thermoregulation, prompting avoidance of dense forests with closed canopies, fast-flowing rivers unsuitable for tadpoles, and barren or sandy terrains.^[34] Some populations show notable urban tolerance, with species like the Atlantic Coast leopard frog utilizing man-made ditches and borrow pits near cities as surrogate habitats.^[38]

Behavior and ecology

Daily activities and movement

Northern leopard frogs exhibit primarily diurnal activity patterns during non-breeding periods, foraging actively during the day while basking in sunny areas to regulate body temperature.^[8] They often become more crepuscular, active at dawn and dusk, and may shift to nocturnal behavior in hot summer conditions to minimize water loss and desiccation risks.^[37] During the breeding season, activity is predominantly nocturnal, though some diurnal calling occurs.^[13] These frogs are adept at locomotion, relying on their powerful hind legs for jumping distances up to 3 feet (about 1 meter) in a single leap to evade predators, a capability enhanced by their elongated, muscular limbs.^[39] They are also proficient swimmers, using fully webbed hind feet to propel through water bodies when diving to escape threats or navigating aquatic habitats.^[1] Outside of breeding, individuals are generally solitary, though males establish small territories around calling sites; post-breeding, they may undertake short migrations of up to 1 km between aquatic breeding areas and upland foraging sites.^[8]^[40] In late fall, northern leopard frogs enter hibernation, remaining inactive from October through early spring in underwater sites with adequate oxygen levels, such as pond bottoms, streams, or burrows in mud and debris.^[1] Emergence typically occurs when water temperatures rise above 10°C (50°F) in late March or early April, signaling the start of spring migrations to breeding ponds.^[41] To deter predators, they are highly alert and wary, emitting a loud distress scream when seized and relying on their mottled spot patterns for camouflage against vegetation and substrate.^[8]^[1] Seasonal movements are pronounced, with adults and juveniles dispersing to upland meadows and grasslands in summer for foraging, often traveling overland during warm nocturnal rains, before returning to permanent water bodies in fall for overwintering.^[41]^[42] These migrations, which can span several kilometers in some cases, utilize moist corridors like ditches and streams to facilitate travel between habitats.^[40]

Diet and predation

Northern leopard frogs are opportunistic carnivores as adults, primarily feeding on a variety of invertebrates such as insects (including beetles, ants, flies, and crickets), spiders, earthworms, snails, and slugs.^[1] Larger individuals occasionally consume small vertebrates, including other frogs, tadpoles, small fish, and rarely birds or snakes.^[43] Tadpoles of northern leopard frogs are primarily herbivorous, grazing on algae, detritus, and periphyton, before shifting to a carnivorous diet following metamorphosis.^[1] Northern leopard frogs employ a sit-and-wait foraging strategy, remaining motionless to ambush prey and using their sticky tongue to capture items, with juveniles targeting smaller prey and adults capable of taking items up to one-third their body size.^[8] Northern leopard frogs face predation from a wide array of animals, including birds such as herons and hawks, mammals like raccoons and foxes, reptiles including snakes, fish such as bass, and other amphibians like bullfrogs, with tadpoles experiencing particularly high predation rates.^[44]^[45] In their ecosystems, northern leopard frogs play a key role in controlling insect populations as predators while serving as prey that supports higher trophic levels; their sensitivity to pollutants also positions them as indicator species for wetland health.^[45]^[46]^[47]

Reproduction and life cycle

Mating and breeding

The breeding season for leopard frogs varies by species and geographic location, typically occurring in spring from March to May in northern populations, such as the northern leopard frog (Lithobates pipiens), and year-round in southern regions for species like the southern leopard frog (Lithobates sphenocephalus), depending on temperature and moisture availability.^[8]^[36] Breeding is triggered by rising water temperatures above 10°C (50°F), with most activity in northern species occurring when temperatures reach 10–18°C.^[30]^[1] Males initiate courtship by producing species-specific advertisement calls from communal choruses at breeding ponds, attracting females who select mates based on call quality and characteristics. The northern leopard frog's call consists of a snoring rattle lasting 2–3 seconds followed by 1–3 chuckles, while the southern leopard frog produces rapid clucks resembling a guttural trill at 10–12 per second, and the Atlantic Coast leopard frog (Lithobates kauffeldi) emits short, single snores or distinct "chucks."^[8]^[26]^[32] Once a female approaches, the male clasps her in axillary amplexus using enlarged thumbs and forearms, maintaining the grip until egg-laying stimulates external fertilization.^[8]^[26]^[48] Leopard frogs exhibit polygamous mating systems, with males potentially clasping multiple females in succession and females mating with several males, leading to intense male-male competition. Smaller or less competitive males often adopt a satellite strategy, remaining silent near calling males to intercept approaching females without producing calls.^[8]^[26]^[49] During amplexus, females deposit 1,000–6,000 eggs in large, spherical masses measuring 2–5 inches (5–13 cm) in diameter, attached to submerged vegetation just below the water surface; these masses consist of multiple clusters, often laid in close proximity within the chorus.^[8]^[48]^[9] Breeding occurs in shallow, sunlit waters with abundant vegetation, such as permanent or temporary ponds, marshes, and slow-moving streams, providing suitable attachment sites for eggs and protection from predators.^[8]^[26] Leopard frogs avoid acidic or polluted waters for breeding, as these conditions reduce reproductive success due to sensitivity to contaminants and low pH levels.^[37]^[50]

Development stages

The eggs of the northern leopard frog (Lithobates pipiens), a representative species in the genus, are laid in gelatinous masses and hatch into tadpoles within 2 to 17 days, with the duration inversely related to water temperature—warmer conditions accelerate hatching to as little as 2 days, while cooler waters extend it to nearly three weeks.^[51] Newly hatched tadpoles possess gills for aquatic respiration, a muscular tail for propulsion, and herbivorous mouthparts adapted for scraping food from surfaces.^[8] During the tadpole stage, which lasts 2 to 3 months (70 to 110 days), individuals grow to up to 4 inches (10 cm) in length, feeding primarily on algae, diatoms, and other plankton while remaining fully aquatic.^[8] This larval phase is highly vulnerable to predation by fish and invertebrates, as well as risks from pond drying, contributing to significant early mortality.^[8] Metamorphosis typically occurs in summer, triggered by surges in thyroid hormones that orchestrate the resorption of the tail, development of lungs and limbs, and restructuring of the digestive system for carnivory; this process carries high mortality rates, often exceeding 95% from tadpole to froglet.^[52]^[8] Emerging juveniles closely resemble miniature adults, complete with spotted skin and the ability to leap, and quickly shift to terrestrial foraging for insects near water bodies.^[8] They reach sexual maturity in 1 to 3 years, depending on resource availability and location, and overwinter in permanent, non-freezing aquatic sites similar to adults, emerging in spring.^[41] In the wild, northern leopard frogs have a lifespan of 2 to 4 years, though individuals in captivity can live up to 9 years under optimal conditions.^[1]^[53] Development is influenced by environmental factors, with cooler climates slowing the overall timeline from egg to metamorphosis, and poor water quality—such as elevated pollutants or nutrient imbalances—reducing tadpole growth rates and survival.^[54]^[8]

Taxonomy

Classification history

The leopard frog genus, encompassing various spotted species of true frogs, was originally classified within the broad genus Rana established by Carl Linnaeus in his Systema Naturae in 1758, which grouped numerous frog species based on morphological similarities such as body form and habitat preferences. The northern leopard frog, a key species in this group, was formally described as Rana pipiens by Johann Christian Daniel von Schreber in 1782, drawing from specimens collected in New York and noting its distinctive dorsal spots.^[55] Over the 19th and 20th centuries, many North American Rana species, including leopard frogs, accumulated historical synonyms due to limited taxonomic resolution, often lumping morphologically similar forms under broad names like R. pipiens.^[56] Advancements in molecular phylogenetics during the early 2000s prompted significant revisions to reflect evolutionary relationships within the Ranidae family. A seminal study by Hillis and Wilcox in 2005 analyzed mitochondrial and nuclear DNA sequences from New World Rana species, revealing deep phylogenetic divergences that warranted separating North American lineages from Eurasian Rana, and proposing subgeneric groupings to address these splits. Building on this, Frost et al. in 2006 published a comprehensive phylogeny of amphibians using extensive genetic data, elevating the North American clade to the full genus Lithobates to better align taxonomy with monophyletic groups, as Rana was paraphyletic. This reclassification positioned Lithobates within the larger Natatanura clade, a major ranoid lineage confirmed by mitochondrial and nuclear DNA analyses that resolved species boundaries and highlighted cryptic diversity among spotted frogs previously conflated under single names. Initially, Lithobates was treated as a subgenus (Rana (Lithobates)) or linked to the subgenus Aquarana—coined for American water frogs including bullfrogs and leopard species—for transitional clarity in nomenclature. However, for taxonomic stability, the full genus Lithobates was widely adopted by herpetological authorities, though debates persist over hybrid formats like Rana (Lithobates) to balance nomenclatural tradition with phylogenetic accuracy. Genetic studies in the 2000s and 2010s further refined boundaries, such as the 2014 description of Lithobates kauffeldi as a cryptic species split from L. pipiens and L. sphenocephalus based on advertisement calls, morphology, and mtDNA/nuclear markers from northeastern U.S. populations. A 2025 study by Chambers et al. provided a workflow for distinguishing species boundaries from intraspecific geographic variation, applied to the leopard frog complex in Mexico and Central America, further addressing cryptic diversity in the subgenus Pantherana. Today, the genus comprises approximately 37 species across North America, with leopard frogs forming a spotted subgroup distinguished by their dorsal patterning and ecological roles.^[24]^[57]^[56]

Recognized species

The recognized species within the leopard frog complex (genus Lithobates, subgenus Pantherana) primarily consist of seven core North American taxa, distinguished through morphological, acoustic, and genetic analyses. These species exhibit varying degrees of sympatry and hybridization potential, with ongoing research revealing cryptic diversity via molecular and bioacoustic methods, including recent 2025 analyses of geographic variation in Mexican and Central American populations.^[58]^[57] The northern leopard frog (Lithobates pipiens) is the most widespread species, occurring across much of Canada and the United States from the Atlantic coast to the Rocky Mountains and northward to the Arctic Circle. It is commonly used in laboratory research due to its adaptability and historical abundance, serving as a model for studies on amphibian development, toxicology, and disease.^[58]^[24] The southern leopard frog (Lithobates sphenocephalus) is abundant throughout the southeastern United States, ranging from Texas to Florida and northward to Virginia, often in permanent wetlands and agricultural areas. Two subspecies are recognized by some authorities—L. s. sphenocephalus and L. s. utricularius (Florida leopard frog)—though taxonomic treatments vary and genetic continuity has led others to consider them synonyms.^[59]^[60] The Rio Grande leopard frog (Lithobates berlandieri) is a larger species (snout-vent length up to 112 mm) found along rivers and streams in the southwestern United States (Texas, New Mexico) and northern Mexico, noted for its prominent external vocal sacs that produce loud advertisement calls. It hybridizes with closely related species like the southern leopard frog in contact zones.^[61]^[62] The Chiricahua leopard frog (Lithobates chiricahuensis) inhabits montane streams and wetlands in the southwestern United States (Arizona, New Mexico) and northern Mexico, particularly in the Sky Island region. It was federally listed as threatened under the U.S. Endangered Species Act in 2002 due to habitat loss and disease.^[63]^[64] The lowland leopard frog (Lithobates yavapaiensis) occupies low-elevation rivers, ponds, and irrigation canals in central and southern Arizona, extending into western New Mexico and northern Mexico; it is morphologically and ecologically similar to the Chiricahua leopard frog but prefers hotter, drier lowlands.^[65]^[20] The Atlantic Coast leopard frog (Lithobates kauffeldi) was described in 2014 based on differences in advertisement calls, mitochondrial DNA, and nuclear genes, distinguishing it from the northern and southern species. It occurs in coastal plain wetlands from North Carolina to Connecticut, including urban and suburban populations in the northeastern United States.^[66]^[67] The plains leopard frog (Lithobates blairi) is sometimes included among core species, ranging across the Great Plains from Texas to South Dakota in grasslands and temporary pools; it is genetically distinct but shows hybridization with the southern leopard frog. Hybrids and potential cryptic species within the complex are subjects of continued acoustic and genomic investigations, particularly in overlap zones.^[68]^[69]

Conservation

Status and threats

Leopard frog species exhibit varied conservation statuses across their ranges, with northern leopard frog (Lithobates pipiens) populations remaining relatively common in eastern North America but experiencing significant declines in the western United States, including severe declines and local extirpations in some areas since the 1970s due to multiple stressors.^[24] The Chiricahua leopard frog (L. chiricahuensis) was federally listed as threatened under the U.S. Endangered Species Act in 2002, reflecting severe population reductions from historical levels.^[64] The Atlantic Coast leopard frog (L. kauffeldi) is considered vulnerable globally, with a conservation status of G3G4, indicating apparent security in some locales but ongoing risks from coastal pressures.^[32] Population trends for leopard frogs show stability in southern regions, such as for the southern leopard frog (L. sphenocephalus), while northern populations have been extirpated from parts of the Rocky Mountains, contributing to its endangered status in that distinct population segment.^[70] These patterns underscore leopard frogs as key indicators of the broader amphibian decline crisis, with average annual population decreases of about 3.79% across U.S. species, more pronounced in western habitats.^[71] Primary threats to leopard frogs include habitat loss from agricultural expansion, urbanization, and wetland drainage, which have fragmented riparian and floodplain areas essential for breeding and foraging.^[72] Pollution, particularly from pesticides like atrazine, exacerbates vulnerabilities by inducing developmental deformities and reducing larval survival in contaminated waters.^[73] Diseases pose acute risks, with the chytrid fungus Batrachochytrium dendrobatidis causing skin infections (chytridiomycosis) and high mortality rates in infected populations, as observed in mass die-offs of northern and Chiricahua leopard frogs.^[42] Ranavirus outbreaks further contribute to episodic declines, affecting tadpoles and adults through hemorrhagic infections.^[72] Invasive species intensify pressures through competition and predation; American bullfrogs (L. catesbeianus) prey on leopard frog tadpoles and adults while transmitting pathogens, and non-native fish such as trout consume larvae in stocked waters.^[74] Climate change compounds these issues by altering wetland hydroperiods, increasing drought frequency, and expanding suitable habitats for invasives in higher elevations.^[75] Additional factors include road mortality during breeding migrations, which can kill large numbers of adults crossing highways; acid rain in northeastern regions, lowering pH levels below tolerable thresholds for egg development (pH <5.8); and overcollection for use as fishing bait or food, historically depleting local populations in accessible areas.^[76]^[77]^[37]

Protection measures

The Chiricahua leopard frog (Lithobates chiricahuensis) is listed as threatened under the U.S. Endangered Species Act, a designation finalized in 2002 due to ongoing habitat loss, predation, and disease threats.^[64] Other leopard frog species, such as the northern leopard frog (L. pipiens), receive state-level protections in several western U.S. states; for instance, it is classified as endangered in Washington and protected in Oregon, reflecting concerns over regional declines.^[42]^[11] Habitat conservation efforts for leopard frogs emphasize wetland restoration and protection of critical aquatic sites. Programs under the North American Wetlands Conservation Act support the enhancement of breeding ponds and riparian zones, which provide essential permanent or semi-permanent water sources for species like the northern and Chiricahua leopard frogs.^[74] Key sites, including national wildlife refuges such as Buenos Aires National Wildlife Refuge in Arizona, are managed to maintain suitable conditions, including water permanence and vegetation cover, through federal partnerships.^[78] Disease management focuses on combating chytridiomycosis caused by the chytrid fungus Batrachochytrium dendrobatidis, a major threat to captive and wild populations. Quarantine protocols during translocation and reintroduction prevent pathogen spread, with infected individuals isolated and tested prior to release.^[79] Antifungal treatments, such as itraconazole baths at reduced concentrations (e.g., 0.01% for up to 11 days) or voriconazole applications, have successfully cleared infections in amphibians including Chiricahua leopard frogs in captivity, often combined with electrolyte therapy to support recovery.^[80]^[81] Ongoing research explores resistant strains, with experimental heat treatments elevating water temperatures to 30°C showing promise in reducing fungal loads without harming frog viability.^[82] Control of invasive species is a priority to protect native leopard frog habitats. Eradication efforts target American bullfrogs (L. catesbeianus), which prey on and compete with leopard frogs; for example, U.S. Fish and Wildlife Service projects in Arizona removed over 450 bullfrogs across multiple sites, leading to the discovery of new Chiricahua populations.^[83] In priority breeding areas, fish removal from ponds—often using barriers or draining—prevents predation on tadpoles, enhancing recruitment success in restored wetlands.^[84] Long-term research and monitoring are coordinated through initiatives like the U.S. Geological Survey's Amphibian Research and Monitoring Initiative (ARMI), which conducts annual surveys to track population trends and habitat use for species including the northern and Chiricahua leopard frogs.^[85] Captive breeding programs support reintroduction; in Arizona, efforts since the early 2000s have released thousands of head-started Chiricahua frogs into managed sites, with the Phoenix Zoo alone contributing over 30,000 individuals by 2025, resulting in established wild populations at refuges.^[86] Public education and policy measures promote sustainable practices to aid recovery. Several states enforce bans on collection and handling of leopard frogs to prevent further population stress, with violations penalized under wildlife codes.^[42] Campaigns advocate for pesticide reduction, including EPA restrictions on atrazine and other chemicals near frog habitats, to mitigate developmental deformities and mortality.^[87] Success stories include the stabilization of Atlantic Coast leopard frog (L. kauffeldi) populations in core northeastern ranges following its 2014 description, where targeted wetland protections have maintained viable groups despite urban pressures.

References

[1]
Northern Leopard Frog (Rana pipiens) | U.S. Fish & Wildlife Service
The northern leopard frog is a smooth-skinned green, brown or sometimes yellow-green frog covered with large, oval dark spots that have a light halo or border.
[2]
Northern leopard frog | Minnesota DNR
General description: The leopard frog is a green or brown frog that has dark spots on its back and legs. Dorsolateral folds are present.
[3]
[PDF] Northern Leopard Frog - Lithobates pipiens
Northern leopard frogs range from New England to the mid‐Atlantic to west of the Rockies, and in Canada, populations exist from southeastern British Columbia ...
[4]
De novo Assembly and Analysis of the Northern Leopard Frog Rana ...
The northern leopard frog Rana (Lithobates) pipiens is an important animal model, being used extensively in cancer, neurology, physiology, and biomechanical ...
[5]
Lithobates pipiens (Northern Leopard Frog) - Animal Diversity Web
Leopard frogs are from 5 to 11.1 cm long. They are green or greenish-brown dorsally, with round, brown spots arranged on their back, sides, and legs. These ...
[6]
Southern Leopard Frog - Missouri Department of Conservation
The southern leopard frog is a medium-sized frog with dark, rounded or oblong spots on the back. The two folds along the sides of the back are narrow, ...
[7]
In vivo muscle force and muscle power during near-maximal frog ...
Mar 10, 2017 · The average jump distance was 59±1cm (> 9 times the frogs' body length) at a take-off angle of 54±1° from the horizontal axis. Table 1 ...
[8]
Northern leopard frog | Washington Department of Fish & Wildlife
The northern leopard frog is a medium to large (3 to 4 inches snout to vent length) aquatic frog with a slender body, thin waist, long legs, and smooth skin.
[9]
Southern Leopard Frog (Rana [Lithobates] sphenocephala)
Spots on the sides and legs are typically smaller than those on the back. A light, sometimes yellowish stripe runs along the upper jaw. Distinguished from the ...Missing: tint shorter
[10]
[PDF] Leopard Frogs of New Jersey
This guide is designed to help differentiate and identify these species through pictures, physical characteristics, acoustic patterns, habitat preferences ...
[11]
Rio Grande Leopard Frog - Lithobates berlandieri - California Herps
The Rio Grande Leopard Frog is an introduced, medium-sized, slender frog with pale green, grayish brown, or olive coloring, and long legs. It is 2.25-4.5 ...
[12]
RIO GRANDE LEOPARD FROG Lithobates berlandieri
DESCRIPTION: A moderate to large (up to about 4.5 inches in length) leopard frog. The dorsum typically has numerous dark spots and raised dorsolateral folds on ...
[13]
Species Profile for Chiricahua leopard frog(Rana chiricahuensis)
Jun 24, 2025 · A leopard frog with a distinctive color pattern of small, raised, cream-colored spots on the thigh against a dark background with relatively rough skin on the ...'' Candidate Information · '' Recovery · Critical Habitat Spatial...
[14]
Chiricahua Leopard Frog (Rana chiricahuensis)
A leopard frog with a distinctive color pattern of small, raised, cream-colored spots on the thigh against a dark background with relatively rough skin on ...
[15]
Lowland Leopard Frog - Lithobates yavapaiensis - California Herps
The Lowland Leopard Frog is a medium-sized, slender frog, 1.8-3.4 inches long, with tan, brown, or green coloring, and dark dorsal spots. It is possibly ...
[16]
[PDF] LOWLAND LEOPARD FROG Rana yavapaiensis Platz and Frost 1984
The Lowland Leopard Frog is a medium-sized frog (4.6-8.7 cm) with gray-green, gray-brown, or tan coloring, irregular blotches, and a yellow ventral pelvic ...
[17]
LOWLAND LEOPARD FROG Lithobates yavapaiensis
Compared to other leopard frogs, the tadpoles are relatively dark, mottled, and stocky. They are similar to Chiricahua leopard frog tadpoles, but browner with a ...Missing: morphological | Show results with:morphological
[18]
Mid-Atlantic Coast leopard frog - Conserve Wildlife Foundation of NJ
This frog is distinguished from other species in the leopard frog complex by its unique mating call, as well as its large external vocal sacs, a faint tympanic ...
[19]
Atlantic Coast Leopard Frog - CT Herpetology
A medium sized frog measuring 2 to 3 inches in length. Color: Dull olive green to brown background coloration with small dark brown to black spots.
[20]
Lithobates pipiens - Northern Leopard Frog - NatureServe Explorer
Large range throughout much of the US and southern Canada; still common in many areas and in a diverse array of pristine and disturbed habitats.
[21]
Northern Leopard Frog (Lithobates pipiens) | U.S. Fish & Wildlife ...
The species is nearly extirpated from almost all of its historical range in Texas, California, Oregon and Washington. Launch Interactive Map.
[22]
Lithobates sphenocephalus | NatureServe Explorer
Range includes the lowlands of the southeastern United States, from southern New York to the Florida Keys, and west to eastern Kansas, central Oklahoma, and ...
[23]
Lithobates sphenocephalus sphenocephalus (Florida Leopard Frog)
Southern leopard frogs are found from New Jersey in the north and south through the Coastal Plain to Florida. The range extends westward through Kentucky, ...
[24]
Lithobates berlandieri (Rio Grande Leopard Frog) | INFORMATION
Rio Grande leopard frogs are 5.7 to 11.4 cm long from snout to vent. The dorsal surface varies from gray to green to brown in color and is covered by many ...
[25]
Lithobates chiricahuensis (Chiricahua Leopard Frog) | INFORMATION
These frogs are similar in appearance to a small, extremely stocky bullfrogs with spots. They are olive to dark green in color, with charcoal spots. The groin ...
[26]
CHIRICAHUA LEOPARD FROG Lithobates chiricahuensis
DESCRIPTION: This leopard frog grows to about 4.3 inches in length, and is a green or brown frog with dorsolateral folds and numerous, relatively small dark ...
[27]
Lithobates yavapaiensis (Lowland Leopard Frog) | INFORMATION
Males are generally smaller than females of the same age. Mass is not reported. This species' color ranges from brown to green with dark marking all over their ...
[28]
Confirmation of a New Leopard Frog Species (Anura: Ranidae) from ...
Oct 29, 2014 · Rana kauffeldi has a mesic distribution that is wider in the north and narrows from Trenton, NJ, to the Delmarva Peninsula. This part of the ...<|separator|>
[29]
Atlantic Coast Leopard Frog - Conservation Guides
Jun 12, 2025 · A brown to green frog with rounded spots, distinct dorsolateral lines, and an occasional white spot on the tympanum. The reticulum (upper thighs) ...
[30]
Amphibians of North Carolina
Distribution Comments: Lithobates kauffeldi has been found in Connecticut, New York, New Jersey, Pennsylvania, Delaware, Maryland, Virginia, and North Carolina ...
[31]
Rana pipiens - AmphibiaWeb
Reports of extirpations and range contractions are common in the western United States, where the species has disappeared from about 95% of their historical ...
[32]
[PDF] California Wildlife Habitat Relationships System
The lowland leopard frog is assumed to be extirpated from California, otherwise extremely rare (Jennings and Hayes, 1994; Clarkson and Rorabaugh, 1989).
[33]
Southern Leopard Frog (Rana sphenocephala)
The southern leopard frog grows to a length of 2 to 3.5 inches (about 5 to 9 cm). Its color varies from tan to several shades of brown to green. The dorsum ( ...<|control11|><|separator|>
[34]
[PDF] Washington State Status Report for the Northern Leopard Frog DRAFT
The northern leopard frog is considered to be highly adaptable to a diversity of habitats (Stebbins. 1951) over a broad range of elevations. It is thought to ...Missing: preferences | Show results with:preferences
[35]
[PDF] Northern Leopard Frog
The northern leopard frog is a slender, medium- sized ranid, sometimes referred to as the “meadow frog” because of its preference for grassy habitats.
[36]
A Guide to Caring for Leopard Frogs as Pets
Sep 19, 2025 · Note that these frogs can jump up to 3 feet due to their powerful hind legs. While domesticated frogs are less prone to jumping, they may ...
[37]
[PDF] Habitat selection, movement patterns, and hazards encountered by ...
Apr 30, 2018 · Northern Leopard Frogs often select wetlands, then grassed areas or forests, avoiding row crops. Home ranges are 4.6-5.9 ha, with some cross- ...
[38]
Northern Leopard Frog | Mass.gov
Apr 11, 2025 · The Northern Leopard Frog is a medium-sized, spotted frog with variable coloration, dark spots with light halos, and a length of 5-9 cm.
[39]
[PDF] Conservation of the Northern Leopard Frog (Rana pipiens)
Northern leopard frogs range throughout the Black Hills and are found at all elevations (Peterson, 1974; B. Smith, unpublished data). Rana pipiens has been ...
[40]
Lithobates blairi (Plains Leopard Frog) - Animal Diversity Web
Food Habits The plains leopard frog feeds on a variety of insects. They mostly use the sit and wait strategy. Once prey items have been sighted, they will ...
[41]
[PDF] Southern Leopard Frogs and the Department of Defense - DOD DENIX
Adults are predatory, primarily consuming insects and other invertebrates, but can eat small vertebrates. Tadpoles eat periphyton and phytoplankton that are ...
[42]
[PDF] STRATEGY - ODFW
They are patient predators, remaining motionless, until they see something that looks tasty. The frog then lunges and captures the prey with a sticky tongue.
[43]
[PDF] Northern Leopard Frog
males have paired vocal sacs and stout forearms with swollen thumb bases with which they hang on to the female. Because they are amphibians, frogs go.
[44]
Northern Leopard Frog - Kootenay Conservation Program
Sep 3, 2021 · Northern Leopard Frogs play an important ecological role as both a predator (of insects) and prey (to herons, fish, turtles and more).
[45]
Plains Leopard Frog | Missouri Department of Conservation
The plains leopard frog is medium-sized, with a light tan ground color and numerous rounded spots on the back. The head is wide and blunt, giving this frog ...Missing: general | Show results with:general
[46]
Northern Leopard Frogs Conservation | Tagging - Northwest Trek
Northern leopard frogs are considered an indicator species. They tell us more about water quality and environmental health. If populations dwindle, as they ...
[47]
Southern Leopard Frog - Chesapeake Bay Program
They have dark green to brown spots on their back, sides and legs that are rounded with light borders. Adult frogs have two prominent yellow or gold ...Missing: irregular | Show results with:irregular
[48]
Frog & toad opera - Minnesota DNR
Northern Leopard Frog, X, X, X. Pickerel Frog, X, X. American Toad, X, X, X. Canadian ... Satellite males, which are often smaller, quietly wait nearby to ...<|control11|><|separator|>
[49]
Chemical Contaminants - AmphibiaWeb
May 14, 2008 · The consequences of chemical stressors, such as pesticides, heavy metals, acidification and nitrogen based fertilizers, on amphibians are lethal, sublethal, ...
[50]
Northern Leopard Frog - Lithobates pipiens - California Herps
pipiens is much of Canada and most of the northern half of the United States, with scattered locations from the northwest south through California and Arizona ...
[51]
The Hypothalamic-Pituitary-Thyroid (HPT) Axis in Frogs and Its Role ...
Metamorphosis of the amphibian tadpole is a thyroid hormone (TH)-dependent developmental process. For this reason, the tadpole is considered to be an ideal ...
[52]
[PDF] Northern Leopard Frog - Gov.bc.ca
sometimes before the last frost. — when the water temperature approaches 10°C.Missing: burrows | Show results with:burrows
[53]
[PDF] Development and Growth of Northern Leopard Frog, Lithobates ...
Figure 4 shows tadpole development. (Gosner stage) at the two monitoring sites. The devel- opment generally followed the same pattern at both sites. However ...<|control11|><|separator|>
[54]
Lithobates pipiens (Schreber, 1782) - Amphibian Species of the World
Daudin, 1802 "An. XI", Hist. Nat. Rain. Gren. Crap., Quarto: 63. Treated as a junior synonym (although senior) of Rana pipiens Schreber, 1782.
[55]
Lithobates Fitzinger, 1843 | Amphibian Species of the World
Evol., 43: 1–13, in a large study of ranid phylogenetics, recognized Lithobates as a genus in the sense of Frost et al. (2006), the sister taxon of Rana, but ...
[56]
Rana pipiens - AmphibiaWeb
Rana pipiens is a slim green or brownish frog, varying in length between about 5 and 11 cm. On its back it has dark rounds spots with pale borders.Missing: original | Show results with:original
[57]
Rana sphenocephala - AmphibiaWeb
genus: Rana. Taxonomic Notes: This species was placed in the genus Lithobates by Frost et al. (2006). However, Yuan et al. (2016, Systematic Biology, doi ...Missing: reclassification | Show results with:reclassification
[58]
Southern Leopard Frog - INHS Herpetology Collection
Key Characters: Dark spots on back rounded; most individuals with light spot on tympanum; few dark spots on sides; no dark spot on snout; long, pointed head.
[59]
Rana berlandieri - AmphibiaWeb
Rana berlandieri, or Rio Grande Leopard Frog, is a large frog with a grey to green or brown back, found in Belize, Mexico, Nicaragua, and the US.<|control11|><|separator|>
[60]
Rana berlandieri - AmphibiaWeb
At 13 sites in central Texas where Rio Grande leopard frogs hybridized with southern leopard frogs, the hybrid zone appeared to be stable over a 3–5-yr period ( ...
[61]
Rana chiricahuensis - AmphibiaWeb
This leopard frog attains an adult snout-vent length of 57-95 mm. Its body is fairly stocky, with rugose skin on the back and sides.
[62]
Listing of the Chiricahua Leopard Frog (Rana chiricahuensis)
Jun 13, 2002 · The Chiricahua leopard frog is now absent from more than 75 percent of its historical sites and numerous mountain ranges, valleys, and drainages ...
[63]
Rana yavapaiensis - AmphibiaWeb
Rana yavapaiensis, or Lowland Leopard Frog, has a cream venter with yellow groin, found in ponds and pools in scrub desert areas of Arizona, New Mexico, and ...
[64]
Rana kauffeldi - AmphibiaWeb
Rana kauffeldi Feinberg, Newman, Watkins-Colwell, Schlesinger, Zarate, Curry, Shaffer, and Burger, 2014. Atlantic Coast Leopard Frog Subgenus: PantheranaMissing: Lithobates | Show results with:Lithobates
[65]
https://amphibiaweb.org/species/5187
[66]
Rana blairi - AmphibiaWeb
Plains Leopard Frog Subgenus: Pantherana, family: Ranidae genus: Rana. Taxonomic Notes: This species was placed in the genus Lithobates by Frost et al. (2006) ...
[67]
Hybridization in leopard frogs (Rana pipiens complex)
I examined the terrestrial performance of Rana blairi, Rana sphenocephala, and four hybrid (two F 1 and two advanced generation) genotypes in replicated ...Missing: bullfrog | Show results with:bullfrog
[68]
[PDF] Distribution and Status of the Northern Leopard Frog, Rana pipiens ...
Species Description: The Northern Leopard Frog, R. pipiens (Figure 1) belongs to the family Ranidae, which is one of the largest families of frogs in the ...<|control11|><|separator|>
[69]
[PDF] Northern Leopard Frog (Lithobates pipiens)
Breeding and larval life occur in pools, ponds, marshes and lakes, and may occasionally occur in slow moving streams and creeks. Moist upland meadows and native ...
[70]
Why are amphibian populations declining? | U.S. Geological Survey
The average decline in overall amphibian populations is 3.79 percent per year, though the decline rate is more severe in some regions of the U.S., such as the ...Missing: 1970s | Show results with:1970s
[71]
[PDF] Northern Leopard Frog Species Status Assessment - NY.gov
Mar 17, 2025 · The northern leopard frog, Lithobates pipiens, is widely distributed across North America. It ranges from the northeastern United States ...
[72]
Effects of atrazine and nitrate on northern leopard frog (Rana ...
Nov 2, 2009 · Thus, concentrations of atrazine and nitrate commonly found in the environment do not appear to pose a significant threat to R. pipiens larvae ...
[73]
Restoration for the Northern Leopard Frog | U.S. Fish & Wildlife ...
Jan 31, 2024 · Reduce water levels at select sites to eliminate bullfrog egg masses and tadpoles · Remove adult bullfrogs to reduce disease transmission, ...
[74]
[PDF] USFWS News Release: Northern Leopard Frog in West, May ...
Jun 30, 2009 · The northern leopard frog is experiencing threats from habitat loss, disease, non-native species, pollution and climate change that individually ...
[75]
[PDF] Reduction in Road Mortality in a Northern Leopard Frog Population
Rain after dark or snow showers followed by sun and above freezing tem- peratures appeared to precipitate migration movements towards the lake. Because of the ...Missing: acid overcollection
[76]
[PDF] Petition to List Western United States DPS of Northern Leopard Frog ...
Jun 5, 2006 · The northern leopard frog's habitat has been destroyed and degraded, poisoned, polluted, and drastically altered, leading to declines. Based on ...<|control11|><|separator|>
[77]
Chiricahua leopard frog with radio tracker | U.S. Geological Survey
Radio-tracking Chiricahua leopard frogs as part of the amphibian monitoring program coordinated by U.S. Fish and Wildlife Service at Buenos Aires National ...
[78]
[PDF] EFFICACY AND SAFETY OF CHLORAMPHENICOL TREATMENT ...
During quarantine, chytridiomycosis was diag- nosed by necropsy and histopathology as the cause of death in one individual despite treatment for this individual ...<|separator|>
[79]
Use antifungal treatment to reduce chytridiomycosis infection
Once excessive skin shedding had started, frogs were treated with miconazole (0.01% solution) or itraconazole (0.1% suspension). Frogs were bathed in the ...
[80]
(PDF) Successful clearance of chytrid fungal infection in threatened ...
Feb 16, 2021 · Six other moribund frogs were given 1 mL drops of 1.25 μg/mL voriconazole daily for 7 days coupled with the aggressive electrolyte therapy.
[81]
Fungicide Clears Infection from Pathogenic Fungus in Larval ...
In this study, we exposed larval southern leopard frog tadpoles (Lithobates sphenocephalus) to the chytrid fungus Batrachochytrium dendrobatidis and the ...
[82]
Control of Introduced American Bullfrogs and Support of Chiricahua ...
Jul 19, 2024 · This report summaries field surveys conducted during July 2023 through April 2024 to control introduced American bullfrogs (Lithobates [Rana] catesbeianus; ...
[83]
Remove or control invasive bullfrogs - Conservation Evidence
Removing bullfrogs can increase native frog populations. Culling metamorphs or managing habitat may also help. Studies show increased red-legged and leopard ...
[84]
The Amphibian Research and Monitoring Initiative (ARMI): 5-year ...
ARMI research and monitoring efforts have addressed at least 7 of the 21 Threatened and Endangered Species listed by the U.S. Fish and Wildlife Service ( ...
[85]
Phoenix Zoo has released 30,000 Chiricahua leopard frogs into wild
Jun 16, 2025 · The Phoenix Zoo has raised Chiricahua leopard frogs from eggs to release into the wild since 1995. For 30 years, the zoo and its partners have ...Missing: reintroduction | Show results with:reintroduction
[86]
[PDF] EPA restricts pesticides that harm rare frogs
Oct 20, 2006 · A conservation group has succeeded in making the federal government restrict pesticide use in some areas inhabited by rare red-legged frogs ...