Bufo valliceps. (Photo: Drew Davis)
While it might be easy to assume we don’t have toads on campus, the Gulf Coast Toad (Bufo valliceps) is one species that does live here. Waller Creek is a one place to see them, in addition to planters where they hide, or on sidewalks at twilight to consume the insects that are attracted to streetlights.
These toads are very common in urban environments, living in any place that provides them adequate moisture and shelter. Outside of the UT campus, they are often found in irrigation ditches, backyard gardens, or storm sewers. During the day, they hide any place they can fit, such as under debris or rocks and bricks. Around twilight during spring and summer, they will come out to their water sources to call for mates and breeding.
The Gulf Coast Toad is native to the extreme south-eastern Mississippi through east and central Texas, and into Mexico. Here in Austin, they have out survived the other species of local toads including Woodhouse’s Toad (Bufo woodhousii), Red-spotted Toad (Bufo punctatus), Texas Toad (Bufo speciosus), and Green Toad (Bufo debilis). Dr. David Hillis of Integrative Biology and the Director of the Biodiversity Center, believes this is due to the appearance of the Red Imported Fire Ant (Solenopsis invicta). “As the fire ants moved west,” Dr. Hillis says, “the toads disappeared with their arrival.”
A Gulf Coast Toadlet. (Photo: Nicole Elmer)
According to Dr. Hillis, these four toads breed in the spring, and the tadpoles will normally transform in May and early June, just around the time water sources become limited. This also is the time when fire ants swarm around the same water holes. The fire ants eat the toadlets that are attempting to leave the water source. Since the toads live only a few years, if a few years of reproduction are lost, then the population is gone.
However, with the Gulf Coast Toad, this species breeds later and also has an extended breeding season. They also survive better in clay soils, according to Dr. Hillis. “So alone amongst our local toads, the Gulf Coast toads have survived, while the other species have gone extinct.”
The Gulf Coast Toad is two to four inches in length, and colors vary amongst individuals. Generally, however, they are dark brown with some yellow-brown to orange touches. They have a light stripe down the middle of their backs. The throat of males is yellow-green, but females lack pigment in this area.
During the breeding season, males will call with a short flat trill that lasts a few seconds. Females lay eggs in strings, and these clutches can contain up to 20,000 eggs. Tadpoles hatch about one to two days after the eggs have been laid, and it will be another 20 – 30 days for them to change into toadlets. These young toads will hang out for a while at their natal pond, but will disperse as they get older, probably a scenario not terribly unfamiliar to many college students!
Listen to a Gulf Coast Toad
This record from Smithsonian Folkways was released in 1958 and contained the sounds of 57 species of frogs. It was compiled and narrated by Charles M. Bogert (1908-1992) and is considered a classic of biological fieldwork and natural sound recordings. Bogert was a herpetologist, and curator of herpetology and researcher for the American Museum of Natural History.
As the Smithsonian Folkways states on their website: "In a time when frog and toad populations are in rapid decline, this recording reminds us of the remarkable diversity and beautiful music we are in danger of losing."
Learn more about this recording here: https://folkways.si.edu/sounds-of-north-american-frogs/science-nature/album/smithsonian
To hear the sample of the Gulf Coast Toad from this record, click here: https://www.youtube.com/watch?v=kZAHAPgOm-w
