It has been a good summer for amphibians. The rains were heavy enough and came at just the suitable intervals for the frogs and toads to breed successfully. Amphibians, as you know, require bodies of water for their tadpole stage. During this first stage, they are aquatic vegetarians. Then they metamorphose into their more terrestrial adult forms and become carnivores. In Greek, “amphi” means “double,” and “bios” means “life,” so the name is apt. Amphibians definitely lead two lives.
Although tadpoles are pretty neat, I find the adult amphibians more fascinating. They have arms and legs. They move about on land. Their eyes are large. And they sing! The frog and toad chorus on a summer night is a symphony of sound. Their songs are distinctive from the bullfrog’s bellow to the green tree frog’s chirp and from the narrow-mouthed toad’s buzz to the Texas toad’s explosive trill. Listen for a while, and you can easily begin to identify frogs and toads by their calls.
Recently, I heard a strange call among the chorus. It was a “Baa-aa-aa!” sound lasting about two seconds and repeated at intervals of approximately 15 seconds. It sounded more like a mammal than a frog. In fact, it sounded like a sheep bleating! No wonder this species got the name sheep frog. It is a pretty frog (although some sources call it a toad) that stays burrowed in the mud much of the year. Only when it comes out to sing and mate can it be observed. Once you hear it, look for it. It is a rather narrow-headed toad with olive-green skin and a lovely yellow line down the middle of its back. They are found in South Texas (and into Mexico) but nowhere else in the United States.
Toads seem to be everywhere right now. I see them hopping through the grass, burrowing into flowerpots, hiding inside my boots and, during the day, tucked away in any moist, shady spot. For some reason, they are fond of swimming in my dog’s water bowl. This morning I scooped five half-grown toads out of the water bowl! What could they possibly have been looking for in there?
The most common toad of our area is the Coastal Plains toad (Incilius nebulifer). It inhabits a wide strip of the Gulf Coast from Mississippi south to Veracruz, Mexico. The Coastal Plains toad was initially classified as part of the species known as the Gulf Coast toad (Incilius valliceps) but was split off as its own species in 2000. The name Gulf Coast toad is now reserved for a species that is found in the Yucatan and Costa Rica.
Another toad that frequents our farm is the Texas toad. This species is one of the burrowing toads; it digs in backward into soft soil or leaf litter. On the underside of each of their hind feet, Texas toads have a tough, brownish tubercle that helps them dig. This slight projection is sometimes called a “spade” and is found on the hind feet of several burrowing species. A whole group of spade-footed toads has elongated, sickle-shaped spades that allow them to excavate a cavity in sandy ground.
So, what makes a toad a toad? And a frog a frog? The distinctions between the two groups are somewhat blurred, but toads generally have warty, bumpy skin while frogs have smooth, slick skin. Frogs have long legs to allow them to swim fast and leap great distances, while toads have shorter legs with which they hop or crawl. Most frogs stay near water as their skin must remain moist, whereas toads can move about with impunity in drier habitats. Still, frogs and toads together make up a group of amphibians with no official boundaries between them.
Ask any amphibian: Are you a frog or a toad? Chances are, it won’t tell you!