Colorado River Toad

The Colorado River Toad is native to the Colorado and Gila Rivers in the United States and are known for their psychellidic secretions. They have relatively smooth skin with few warts and grow up to 7.5 inches in length.

Common NameColorado River Toad
Other Names Sonoran Desert Toad
Scientific NameL. alvarius
LocationsSouthwestern United States
Northern Mexico
CharacteristicsLarge body
Brown or olive green leathery skin
Large parotoid glands
ColorMottled brown and olive green
Origin Colorado River
Conservation StatusLeast Concern
Family Bufonidae
GenusIncilius
SpeciesL. alvarius
PoisonousYes
Max Length7.5 inches
Max Weight4.2 grams
Lifespan4-12 years

Colorado River Toads are unique in that they do not have very warty skin like most toads. Their skin is fairly smooth, which is not that surprising since they can be found in river water around Colorado. They have mottled brown or olive-green skin.

Their forelimbs are relatively short, but their hind limbs are longer and have toes made for digging. They help the toads to hop around with relative ease, though they are quite sluggish compared to frogs. They have webbed hind feet which is also rare for toads, which enable them to swim in the water.

Colorado River Toads have highly toxic secretions containing 5MeO-DMT. Bufotenin and 5MeO-DMT are known to cause psychedelic reactions in people, but can also cause poisoning and death. It is therefore illegal to be in possession of a Colorado River Toad in the state of California:

“It is unlawful to capture, collect, intentionally kill or injure, possess, purchase, propagate, sell, transport, import or export any native reptile or amphibian, or part thereof […]”

California Code of Regulations

People have already been arrested for transporting or possessing Colorado River Toads in many states including Colorado, California, Arizona and New Mexico.

Tips on How to Spot the Colorado River Toad

After reading the above paragraphs, you know it is illegal to capture or collect these frogs, so be sure to only take pictures from afar if you spot them in the wild. 

The Colorado River Toad has a flat body and its head is shaped like a spade. It has very distinct eyes with ridges around them making them naturally look aggressive. Its parotoid glands are very large and are just behind both of its eyes. 

Surprisingly, the Colorado River Toad can live in the Sonoran desert, which is quite dry. You can find them not only along the Colorado River, but also in the Gila River area, Southeastern California, Southern Arizona, and Mexico.

If you would like to spot a Colorado River Toad, here are some useful tips:

  • Colorado River Toads are nocturnal animals, meaning they are most active at night while hunting for prey.
  • In the daytime, they usually stay in burrows or small pools of water in the shade.
  • Male Colorado River Toads usually make a mating call to attract females during the mating season.
  • Colorado River Toads can stay submerged in ponds for long periods during the daytime. Check still water bodies for toads in the daytime.
  • Do not touch them, interact with them or get too close or you risk getting questioned by police.

The Colorado River Toad is semi-aquatic, so it resides in areas close to freshwater. Although it likes natural freshwater such as springs and streams, you can sometimes find this amphibian in water troughs and even reservoirs.

Interesting Facts About Colorado River Toads

  • Colorado River Toads are the second largest species of toads in the United States, growing to a fairly large 7.5 inches.
  • Rather than digging their burrows, Colorado River Toads generally occupy the burrows of small rodents and prey on them.
  • A Female Colorado River Toad can lay up to 8,000 eggs during the breeding season.
  • The skin of the Colorado River Toad is so poisonous that it can kill a full-grown dog within hours of contact with its toxin.
  • Colorado River Toads can survive in deserts. Nevertheless, they prefer sitting in water to cool off during the day.
  • It is illegal to possess these toads in all of the states where they are located.
  • Their population is in decline due to the illegal drug trade.

More About Colorado River Toads

Colorado River Toads are one of the most fascinating species of amphibians on earth. They are a rare mix of terrestrial and aquatic frogs since they can live on land and in water, even in arid conditions.

Learn more about Colorado River Toads in these guides on our blog:

Related Questions About the Colorado River Toads

Can you keep a Colorado River Toad as a pet? Possession of Colorado River Toads is illegal in all the states where they are located, notably because of their toxic secretions that are generally used in the drug trade. Therefore, Colorado River Toads cannot be kept as pets.

What do Colorado River Toads sound like? Although most people imagine these amphibians to possess loud croaks, the sound they make is much gentler. Male Colorado River Toads make a quick and barely audible low-pitched trill during the mating season.

Why do Colorado River Toads make those sounds? Male Colorado River Toads usually make sounds and calls to attract females of the same species to them during the breeding season in order to mate and reproduce.

What do Colorado River Toads eat? Colorado River Toads eat many things ranging from small snails and slugs to wall geckos and other toads. Larger toads also eat small mice, grasshoppers, butterflies, scorpions, and small birds.

What are Colorado River Toads’ predators? There are a few animals that can resist the toxins the Colorado River Toad secretes other than a few snakes and birds, and therefore these toads generally have less predators than most frogs.

How many eggs can Colorado River Toads lay? Female Colorado River Toads usually lay up to 8,000 eggs once per season. These eggs take a few days to transform into tadpoles that then metamorphose into toadlets. Many of their eggs and tadpoles are eaten before they become adults.

How often do Colorado River Toads breed in a year? Colorado River Toads breed once a year between May and August. This is when you can generally hear male Colorado River Toads calling females to their location to breed.

Are Colorado River Toads poisonous? Colorado River Toads are very poisonous to humans and pets. In addition to the parotid glands that produce deadly bufotenin, the glands on their skin release equally toxic chemicals that have psychedelic properties. 

Are Colorado River Toads Endangered? Colorado River Toads are not an endangered species and  are listed as  ‘least concern’ in the IUCN red list of endangered species. Although they are not endangered their numbers are steadily declining due to natural habitat loss and the illegal drug trade.

Sources

Geoffrey Hammerson, Georgina Santos-Barrera. 2004. Incilius alvarius. The IUCN Red List of Threatened Species 2004: e.T54567A11152901. https://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T54567A11152901.en

Gowda RM, Cohen RA, Khan IA. Toad venom poisoning: resemblance to digoxin toxicity and therapeutic implications. Heart. 2003;89(4):e14. doi:10.1136/heart.89.4.e14

California Code of Regulations, Title 14 – Natural Resources, Division 1 – Fish and Game Commission-Department of Fish and Game, Subdivision 1 – Fish, Amphibians and Reptiles, Chapter 5 – Native Reptiles and Amphibians, Section 40 – General Provisions Relating to Native Reptiles and Amphibians
Universal Citation: 14 CA Code of Regs 40, § 40. General Provisions Relating to Native Reptiles and Amphibians