Frog of the Week

Colorado River Toad (Incilius alvarius)

Colorado River Toad
Colorado River Toad photo by William Flaxington

Common Name: Colorado River Toad and Sonoran Desert Toad
Scientific Name: Incilius alvarius
Family: Bufonidae – True Toad family
Locations: United States and Mexico
US Locations: Arizona, California, New Mexico
Size: Females can reach up 7.3 inches (187 mm) long, while males are shorter at 6 inches (156 mm)

The Colorado River Toad is the second largest native toad species in the United States, next to the Cane Toad. The toad is more famous for the fact that it’s psychoactive because it produces 5-MeO-DMT and Bufotenin, which are hallucinogens. These drugs are illegal to possess, distribute, buy, or manufacture in the United States. Possession of the toad is not illegal but the police can arrest if they believe you own them for making drugs. It’s also illegal to take the toad from the wild in California and New Mexico. If you are still thinking about using the toad to get high, the toad is also poisonous and has been known to kill dogs that eat them. A recent study has shown that smoking the compound 5-MeO-DMT can help alleviate symptoms of depression and anxiety.

The Colorado River Toad is nocturnal, staying burrowed during the day and coming out at night to hunt. They will eat anything they can fit in their mouth including scorpions, ants, toads, lizards, and mice.

Colorado River Toad
photo by John P Clare

When the summer rain starts, the breeding season for the Colorado River Toad starts, usually in May. The breeding season can last until August. At the start, the males can call out to attract females for mating but usually they search them out. Once the male finds a mate, he grasps her from behind in the amplexus position. Then, the female lays her eggs and the male fertilizes them. The females average laying around 8000 eggs. Neither parent provides any parental care for their offspring. The eggs hatch into tadpoles that develop into toadlets in under a month.

The International Union for the Conservation of Nature (IUCN) Red List assesses the toad as Least Concern for Extinction. They have a decent size range and are thought to be numerous throughout it.

6 thoughts on “Colorado River Toad (Incilius alvarius)”

Leave a Reply