Southern Leopard Frog (Lithobates sphenocephalus)
Alternate names: Rana sphenocephala
by Jeff LeClere
Southern leopard frogs, Lithobates sphenocephalus, calling.
Species of Greatest Conservation Need. A valid fishing license is required to possess this species for bait or food. These frogs are uncommon and rather tough to distinguish from Iowa’s other leopard frog species. They are primarily found in southern Iowa. We would welcome any reports of this species.
The southern leopard frog is the most uncommon of the leopard frogs in Iowa. They may grow to 3 1/2 inches body length. Southern leopard frogs are green or brown on top with a few round black spots scattered randomly about the back and on the sides, but none on the snout. The belly is plain white. There are two light complete dorsolateral ridges down the back. There are spots on the forelimbs and tiger stripes or bars on the hind legs. The groin and thighs have a greenish (very rarely yellowish) wash.
They differ from pickerel frogs by having round spots scattered randomly about the about the back, and a greenish wash on the thighs. Also pickerel frogs are found only in the trout streams of extreme eastern Iowa.
One subspecies is found in Iowa, the Coastal Plains leopard frog, Lithobates spenocephalus utricularius.
The southern leopard frog is found primarily in southeastern Iowa, but recent records show its range expanding into central Iowa.
The southern leopard frog is found in all water types. Lakes, ponds, rivers, streams, large and small wetlands, even homemade ponds. Leopard frogs move considerable distances from water, especially in wet grasslands or damp woodlands.
Southern leopard frogs breed in March and April. Sometimes males call while underwater. They produce a chuckling call. Their call lacks the long snore heard in the call of northern leopard frogs. A single female may lay 3,000 to 5,000 eggs in a round mass. The females may all lay eggs in one portion of the pond. Tadpoles metamorphose in about three months. During rainy weather, (especially during spring or fall migrations) great numbers of leopard frogs are seen crossing the roadway, especially near wetlands. During the summer they may venture into backyards and move into outdoor ponds or swimming pools. When they move far from a body of water, they may absorb dew to keep them moist. They overwinter in deep water. This is the most uncommon of all the leopard frogs found in Iowa. They closely resemble northern leopard frogs in appearance and their call can be easily confused with the call of the plains leopard frog. Automobiles take their toll on these frogs and any medium or large sized carnivores prey upon them.
Southern leopard frogs consume insects, earthworms, and other invertebrates.