Colorado River Toad (CRT) aka Sonoran Desert Toad
This giant toad appeared by my back step yesterday, May 13, 2013, and remained all day, moving only once in the afternoon to stay in the shade. This is the first of these toads I have seen here, though it is obvious that this individual has been here gobbling insects and growing for at least two years.
July 1, 2014: Haven’t yet seen the CRT.
The California River Toad (CRT) (Bufo alvarius a.k.a. Ollotis alvariaare and Incillius alvarius) or Sonoran Desert Toad lives in southern Arizona and desert areas of New Mexico. It formerly lived in southeastern California. Above the desert, CRT is found near streams and lakes. My place in central Arizona is near the species’ northern limit.
At seven and one half inches long, CRTs are the largest native toads of the U. S. This one is about five inches (and almost as wide ;-).
These toads are primarily nocturnal. They are not as visible or noisy as the Rocky Mountain Toads that live in my yard. Though I did not know they were here, the CRTs are probably an important reason that I have no insect problems despite the lawns around the house and the large stock ponds only a few hundred feet away.
This chubby amphibian has powerful defense toxins. Glands on its sides, back, and legs produce the toxins. Predators absorb the toxins through their nose, eyes, and mouth. Dogs that mouth one of these toads can become paralyzed. The toxin is hallucinogenic, and several states have classified it as a controlled substance. Perhaps “toad lickers” are partially responsible for the toad’s decline.
The CRT eats anything it can catch and fit in its mouth, even small mice. It can enter homes through pet doors. A welcome visitor, the toad will roam about eliminating household pests while providing amphibian decor unique to the Southwest. I haven’t had this good fortune yet, but I am optimistic.
The CRT has disappeared from its former range in California, and is declining in Arizona and New Mexico. It is a candidate for protection under the Endangered Species Act. A google search will provide more information.