Delta Journal
by Bob Thomas

Most of us associate frog breeding with warm rainy nights in spring and summer. There are, however, several local frog species that restrict their breeding to cooler weather, mating throughout our winter months.

One is the Spring Peeper, Pseudacris crucifer, an inch-long tannish-brown frog with a dark brown cross on its back. Peepers are normally found in woodlands near ponds or swamps, though they may be encountered in adjacent open areas. Their mating call consists of a repetition of one to two second ascending whistles separated by one or more second pauses.

The heartier of our winter breeders is the Upland Chorus Frog, Pseudacris fouquettei. It is similar in size to the Spring Peeper, but its pattern consists of several broken dark stripes on a greyish-brown background. Chorus frogs prefer open areas for breeding, most often being found around grassy ditches and ponds. The mating call resembles the sound created by running a thumb across the stiff teeth of a plastic comb. The rate of individual clicks in the trill of the call varies with the temperature - very fast on warm nights and very slow on cold nights. These little fellows are so cold tolerant that they have been observed actually breeding while immersed in the open water around the base of vegetation emerging from an otherwise frozen-over pond!

The tadpoles of the winter breeding frogs metamorphose about the time the spring breeders become active. Presumably, the two species “choice” of breeding time has allowed them to avoid competition with the numerous frogs that are active during the warmer months.

These two species disappear from the breeding sites in March or thereabouts, though they are rarely heard calling later in the year. They presumably become inactive from that time until the next fall when breeding activity again commences.

A third species commonly breeds during our winter months, but may be found breeding year round. This is the Southern Leopard Frog (Rana sphenocephala). It seems to prefer the colder months, being very commonly heard while peepers and chorus frogs are calling. Its call is a series of chuckles followed by the sound that one gets rubbing two pieces of rubber together. Very distinctive, but hard to describe. Unlike the other winter breeders, leopard frogs are active in all months of the year.

Also published in Nature Profile, The Times Picayune, March 31, 1982.