Natural History: S. Leopard Frog

Second stop of our last Herpetology field trip for the semester, and I still hadn't found a new specimen to blog about, but I wasn't going to let that stop me from the pure joy of chasing cricket frogs dispersing at my every step. I followed two to a miniature inlet, losing them in the loose leafs along the waters edge. Scanning, I saw the yellow outline of a larger frog wedged into the mud. Plucking it from its moist surroundings, I noticed its beautiful markings, giving way to its identification.

Lithobates sphenocephalus, the Southern Leopard Frog, formerly known as Rana utricularia, of the Ranidae family. This specimen was approximately 2 inches (average adult size), sex undetermined and very calm. 

This species is a range of green to brown in color, with various dark dorsal spots. The upper jaw line and uninterrupted dorsolateral ridges are pale yellow in color. A light spot in the center of the tympanum, is also characteristic. 

Pickerel frog with squarish spots and bright orange/yellow on concealed surfaces of the hind legs, and Gopher and Crawfish frogs with fat, chunky bodies and rounded, nonpointed snouts, are similar but easier to distinguish from the Leopard frogs. 

Southern Leopard frogs are found in shallow, freshwater habitats, even slightly brackish marshes in the south eastern quarter of the United States and along the Atlantic coast. In areas of overlap, identification from the other three Leopard Frogs is slightly more challenging. The Northern Leopard frog has nearly invisible vocal sacs when at rest (other three do not), the Plains Leopard and Rio Grande Leopard frogs have interupted dorsolateral ridges (southern does not).