Pleistocene Toads

During the first months of 1976 I was the new kid at Patty Hilsman Middle School in Athens, Georgia where a group of cruel, little jerks decided to give me the nickname–toad. The nickname stuck immediately. Jocks, nerds, “cool” kids, and pretty girls all referred to me as toad instead of my given name of Mark. I was 13 years old, and the experience didn’t enhance my self-esteem. It also gave me a dim view of southern hospitality (our family had moved from Ohio), and after living in the South for over 45 years, I can confirm it is a myth. I saw a southern toad (Bufo terrestris) hopping in my yard the other day, and it brought back the unpleasant memory of being likened to an ugly amphibian. Nevertheless, it also reminded me that I’ve never written about this amazing Pleistocene survivor. Toads may seem insignificant, but they have outlasted many of the beautiful more dynamic animals that lived during the Pleistocene.

Southern toad. This species is common in my yard. Photo from Alamy.

Georgia is home to 2 species of true toads, 1 species of spadefoot toad, and 1 species of narrow-headed frog that is given the common name of toad. Southern toads are the most common species. They live in areas with sandy soils where they can burrow during the heat of the day. They hunt insects at night. After heavy rains, they breed and lay eggs in temporary pools where, if the pool doesn’t dry out, their tadpoles can metamorphize into adults. Fossil evidence of southern toads dating to the Pleistocene has been found at 6 sites in Florida and 1 site in Alabama. They were likely just as widespread then as now.

Oak toad. My neighborhood is close to the northern range limit for this species. I’ve seen small toads in my yard but they may be juvenile southern toads. Photo from pininterest.

Oak toads (Bufo quercicus) also prefer sandy soils and are common on coastal plain pine savannahs. This species is small, growing to just an inch in length. Fossil evidence of this species dating to the Pleistocene has been found at just 1 site in Florida (Reddick).

Eastern spade foot toad. They live in spiral burrows underground but emerge above ground to breed.

Eastern spade foot toads (Scaphiophus holbrooki) belong to the Pelobotidae family and are not closely related to true toads. They are named for a protuberance found on both feet that helps them dig deep spiral burrows where they spend most of their life, and for this reason they are rarely seen. Their burrows are much deeper than those of the true toads. After heavy rains, they emerge to breed and lay their eggs in temporary pools. This species is so well evolved to live in pine savannahs they can survive the light ground fires that occur in their environment. Fossil evidence of this species dating to the Pleistocene has been found at 10 sites in Florida.

The narrow-mouthed toad is not a true toad but belongs to the narrow-headed frog family. Photo from wild herps.

Narrow-mouthed toads (Gastrophyne carolinensis) are not true toads but instead belong to the narrow-headed frog family (Microhylidae). This species burrows near wetlands and spends much of its time in emergent wetland vegetation. They mostly eat ants. Fossil evidence of this species has been found at Ladds in northwest Georgia.

Woodhouse toads (Anaxyros woodhouseii) no longer occur on the southeastern coastal plain of North America, but their fossil remains have been found at sites in Florida and Alabama. The reason for their regional disappearance is a mystery. Perhaps, unlike other species of toads here, they are not well adapted to human set fires.

Toads secrete poisons that make them unpalatable to mammalian predators. However, toads do make up the majority of the hog-nosed snake’s diet. Toads do have a defense mechanism against the snakes too. They swell their bodies, making them hard for the snake to swallow. Sometimes this defense mechanism works and sometimes it does not.

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