The southern leopard frog is a medium-sized frog with rounded or oblong spots on the back. The two folds along the sides of the back are narrow, distinctly raised, yellow or tan, and run continuously to the groin. The head appears long and the snout is pointed. The general color is green, greenish brown, or light brown with some green on the back. Dark marks on the hind legs are broken bars or elongated spots. There is usually no dark spot on the snout. A white line is present along the upper lip. The center of the tympanum (round, external ear) usually has a distinct white spot. The belly is white. Call is a series of abrupt, chucklelike quacking sounds, repeated at a rate of 12 pulses per second. Tadpoles are 1¾–2¼ inches long, olive-gray, with faint gray markings on body and tail.
Similar species: The southern leopard frog differs from our other leopard frogs and the pickerel frog by its narrow, continuous dorsolateral fold, pointed snout, usual lack of a snout spot, lack of yellow along the groin and inner thighs, and absence of white rings around the spots on the back.
In a number of Missouri counties, the southern leopard frog and plains leopard frog occur in the same geographic range, and hybridization with these two species may occur. This is especially likely in places where habitats have been altered due to human activity. When a breeding habitat is changed, the environmental barriers that would normally isolate species during their breeding season are lost, and hybridization may occur.
Missouri has eight members of the true frog family. These are typically medium- to large-sized, have long legs, smooth skin, and well-developed webbing between the hind toes. Another common characteristic is a glandular fold or ridge of skin along each side of the back (these are called dorsolateral folds).
Adult length (snout to vent): 2–3½ inches; occasionally to 5 inches.
Throughout most of Missouri except for the northwestern corner of the state.
Habitat and Conservation
During the summer months, southern leopard frogs may venture far from water into pastures, meadows, or wooded areas where they search for insect prey. When near an aquatic habitat, leopard frogs sit at the water’s edge but quickly enter the water with a powerful jump if alarmed. This species uses a wide variety of aquatic habitats including creeks, rivers, sloughs, swamps, marshes, ponds, lakes, and flooded ditches. Due to a high rate of evaporative water loss, this species must remain near water or use burrows of mammals and crayfish to escape hot summer conditions. Recently transformed adults will actively burrow into the substrate or use existing burrows to avoid water loss during drought.
Southern leopard frogs eat a variety of insects and other invertebrates.
Widespread and quite common in Missouri.
Taxonomy: The true frog family (Ranidae) is the largest and most widespread family of frogs. It contains 365 species in 14 genera and probably originated in Africa. Representatives of this cosmopolitan family occur on every major land mass except New Zealand, Antarctica, most oceanic islands, the West Indies, and southern South America. The largest genus in the family in the New World (North and South America) is Lithobates (formerly Rana), with about 50 species. Missouri’s species, formerly in genus Rana, are all in genus Lithobates. As of taxonomic understandings in 2016, the Rana genus is considered restricted to the eastern hemisphere and western North America. In Missouri, the genus Lithobates is represented by eight species.
In our state, this species is normally active between late February and mid-October. Adults migrate to breeding ponds in spring, where they breed from early March into July. The peak of breeding is from mid-March to mid-May. Ponds, sloughs, and flooded ditches are used as breeding sites. Several thousand eggs are normally laid in several clumps or masses, which are loosely attached to submerged sticks or stems. Eggs hatch within 2 weeks, varying with water temperature, and tadpoles metamorphose from mid-June to September. Sometimes this species breeds during the autumn and the tadpoles overwinter in the breeding wetland.
Missouri’s anglers sometimes use southern leopard frogs as live bait (daily limits apply, however; check current fishing regulations to make sure you’re using them legally).
Many Missourians enjoy observing these attractive frogs as they plop into the water and sing their courting calls.
This species preys on a variety of insects and spiders and is in turn preyed upon by ribbonsnakes, gartersnakes, and other predators. The eggs and tadpoles become food for many wetland predators.
Long-term calling surveys in Missouri show that the number of southern leopard frogs calling is highly influenced by weather conditions. During the 2012 drought in Missouri, very few southern leopard frogs were heard calling across the state, but they readily rebounded the following wet years.