The Colorado River Toad is a large species of toad that can be kept in groups. For the intermediate to advanced toad keeper, these bold toads can be very fascinating.

Name

Colorado River toads go by the scientific Incilius alvarius. It is typically called the Colorado River Toad, and sometimes the Sonoran Desert Toad. Up until recently these were known as Bufo alvarius.This toad is in the family Bufonidae, and is considered a true toad. 

Recommended Vivarium Size

Housing Incilius alvarius can be tricky due to their size as adults. These anurans require a lot of space, but they do not need a very complex habitat. Something the size of an 24x18x18 Exo Terra Glass Terrarium can house 1-2 adults, while a 20 gallon long could house about the same amount of toads. Ventilation is a must, as these toads will not tolerate stagnant moist air for very long. A screen top will help provide this.

Substrate recommendations vary considerably, but ground coconut fiber works well for Josh’s Frogs and the bioactive option is BioBedding, both of these should be kept on the drier side. Provide plenty of decor that your Incilius alvarius can climb and hide in, such as  cork bark tubes and flats. Our toads really seem to like the Exo Terra Smart Plants. A shallow water bowl should be provided, as well. Colorado River toads do benefit from UVB lighting such as a 5.0 or UVB100 UVB bulb.

Temperature

They can tolerate temperatures from 65F to over 85F, but ideally are kept slightly warmer than room temperature, from the mid to high 70s. A low wattage basking spot can help to elevate temeratures into a safe range.

Humidity

 In the wild, precipitation and humidity fluctuate based on season, with a light rainy season in the early part of the year. Colorado River toads can handle a wide range of humidity levels, but prefer humidity levels around 40-60% with plenty of ventilation/air movement. Moist, stagnant air is a big no-no when keeping older Icilius alvarius, while very young animals dry out easily and prefer an elevated humidity. Routine misting and a full screen top will aid in providing proper humidity levels. Colorado River Toads handle short periods of low humidity much better than most tree frogs.

Size

Adult Colorado River toads are quite large, and there is sometimes a size difference between males and females. An adult male may reach between 4-6 inches, but most will be closer to the 6"" mark. A large female will be larger and bulkier than a male, and may measure up to 7.” All of the Colorado River Toad toadlets Josh's Frogs sells are well started juveniles, and measure about 1"" long. When they come out of the water they are typically just under 1/4"" long but can be larger.

Age

There isn't any good data surrounding the average lifespan of Colorado Toads, but wild caught animals have lived in captivity for 5 or more years. Due to the size and maturation rate likely being at least 2 years, Colorado River Toads can likely live in captivity for over 10 years, although there are reports of toads living to 20. All Colorado River Toads for sale at Josh's Frogs are well started juveniles, and are 2-3 months old.

Feeding

Colorado River Toads really like to Burrow, and often times spend a lot of time underground during the day under hides or cork flats/tube and tend to be more active at night. You should plan your feeding times accordingly. Colorado River Toads can eat rather large food, and easily consume adult crickets and roaches as adults. At Josh’s Frogs, we feed our adult Colorado River toads primarily adult crickets, as well as Blaptica dubia roaches, and the occasional superworm, waxworm, or hornworm. Young Colorado River Toads start life feeding on springtails. At the size Josh’s Frogs sells captive bred Colorado River toads, they are eating 1/8"" to 1/4"" crickets. All prey items should be dusted with a quality vitamin/mineral supplement.

Sexing

Sexing adult Colorado River Toads is quite easy when you know how to do it. Once the toads are about 10-12 months old, they display subtle sexual dimorphism. Females are a bit larger then males, and more rotund. Males are a bit smaller, more slender, and emit a release call when grabbed around the belly. Males will also have a dark nuptial pad and robust forearms to facilitate in amplexus. Color variations exist between individuals, but do not seem to be tied to sexual dimorphism. A Colorado River toad's call is very loud and hard to miss!

Color/Pattern

Colorado River Toads are a fairly uniform species. Their coloration is typically an olive green to grey with varying amounts of bronze spotting. Ventrally, their coloration is lighter. Tips of the fingers are usually black or dark brown. There are white spots at each end of the mouth.

Social Behavior

These toads are not outwardly aggressive towards each other, and do great when housed in groups. At Josh's Frogs, we have not seen any aggression between males or females in our adult group of over 10 animals. During breeding, males can and will amplex without discretion and sometimes even end up with multiple males amplexing a single female. As long as the individuals are able to keep their heads above water, this behavior is not harmful but, for this reason, a male to female ratio of 2-3:1 is recommended for breeding.

Breeding

Captive breeding of Colorado River toads has happened before but with the number of resulting toadlets, it's not necessary to make this a frequently bred species. Colorado River toads in the wild will breed during the wet seaon with rain being a pretty big trigger. In captivity, the toads seem to need a rain simulation for several hours overnight as well as moving water as they breed in rivers. Colorado River Toad egg clutches average between 7,500-8000 eggs.

Natural Range

This species' geographic range extends from Arizona, California, New Mexico, and down in to northern Mexico. This species has not been seen in California since the 1950s and is listed as an Endangered species in that state.

History in the Hobby

 Colorado River toads have ownership and collection restrictions in the states that they occur naturally. California has restrictions on owning this species outright.

Toxin Note

As with most toads, Colorado River Toads have toxin glands behind their eyes called paratoid glands. Captive toads are more hesitant to secrete a toxin than their wild caught couterparts, but caution should still be made to prevent this toxin from being ingested or come into contact with mucous membranes or cuts. You'll want to make sure these toads are kept away from other pets for both of their safety. Always be sure to thoroughly wash your hands after handling this species. If poisoning occurs in dogs, cats, or people, seek medical attention immediately.

Links of Interest

amphibiaweb

https://www.oaklandzoo.org/animals/colorado-river-toad

Still not sure if Incilius alvarius from Josh's Frogs are the right pet frog for you? Check out what else we have to offer at http://www.joshsfrogs.com.