NATURAL HISTORY

CHIRICAHUA LEOPARD FROG } Rana chiricahuensis
FAMILY: Ranidae

Populations north and south of the Gila River are genetically distinct and will likely be separated into different species in the future. Meanwhile, recent genetic analysis indicates that the highly imperiled Ramsey Canyon leopard frog (Rana subaquavocalis) is indistinguishable from the southern form of Rana chiricahuensis and will likely be subsumed into the listed species soon.

DESCRIPTION: Stockier than other leopard frogs, the Chiricahua looks like a small bullfrog with spots. The adult ranges in size from about two to five inches in length, and females are larger than males. Coloring is usually an olive to dark green, with charcoal spots, a green face, and yellow groin and abdomen.

HABITAT: These frogs inhabit a variety of permanent aquatic locales including springs, streams, man-made and natural ponds, and lakes with abundant aquatic vegetation. They exist from elevations of 3,280 to 8,600 feet, in places where adequate water depth provides escape from predators.

RANGE: Historically and today, the Chiricahua leopard frog occurs in both desert and mountain streams and wetlands in central and southeast Arizona, southwest New Mexico, and northern Mexico, though the mountain and desert populations may be declared separate species. Eighty percent of this frog’s habitat has been lost to livestock grazing, dams, and water diversions, and the species is now often restricted to springs and streams in the upper portions of watersheds where nonnative predators have yet to invade. Though the frog lives in some stock tanks in Arizona, the U.S. Fish and Wildlife Service believes these populations are too small and isolated to be considered viable.

MIGRATION: This frog is nonmigratory.

BREEDING: During mating season, the female lays 3,000 to 6,000 eggs in a large, flattened mass just below the water surface. One month after the eggs are laid, tadpoles emerge.

LIFE CYCLE: The frog will reach sexual maturity two to three years after eggs are laid, and they have a lifespan of up to 18 years in the wild.

FEEDING: Chiricahua leopard frogs likely eat a wide range of invertebrates, including caterpillars and beetles.

THREATS: Destruction of vegetative habitat by livestock, conversion of natural springs, pools, and wetlands to stock tanks, and introduction of exotic species to cattle stock tanks are hurting the frogs. So are nonnative predators — especially bullfrogs, fishes and crayfish ­— as well as water pollution and the widespread chytridiomycosis, a fungal skin disease. Drought, floods, groundwater pumping, isolated populations, and small numbers of individuals also contribute to population drops. Loss of this frog fits a pattern of global amphibian decline, suggesting that other regional or global causes of decline may be important as well, such as elevated ultraviolet radiation, pesticides or other contaminants, and climate change.

POPULATION TREND: The Chiricahua has declined more than any other leopard frog in Arizona. Once found in more than 400 aquatic sites in the Southwest, the frog is now found at fewer than 80. Since being placed on the threatened species list, due to agency mismanagement, the frog has continued to decline at cattle stock tanks in New Mexico and Arizona.

 

Photo © Erik Enderson