Other common names: Colorado River Toad
Scientific name: Incilius alvarius
Despite its impressive size and unique appearance, the Colorado River Toad has not been well-studied. Captives have done very well, but given their declining populations, these desert specialists should be left to experienced keepers until captive breeding becomes more regular. Their skin secretions have (most foolishly!) been abused as hallucinogens, and may be fatal if swallowed, so the animals themselves are treated as controlled substances in most US locales.
The range extends from the southern reaches of Arizona, New Mexico and California, USA to northern Sinaloa and Baja California, Mexico. Adapted to arid habitats, the Colorado River Toad is found in deserts, dry grasslands, mesquite scrub, and open woodlands.
Appearance / health:
The olive skin is quite “un-toad-like” in texture, being very smooth and bearing small, round tubercles. The body is squat and rounded in profile. Adults reach 11-19 cm (4.4-7.6 in) in length.
Although we know little of their natural history, Colorado River Toads have lived for at least 35 years in captivity. “Short-Tongue Syndrome” (related to a Vitamin A deficiency), low Calcium levels, and digestive tract blockages resulting from substrate ingestion should be guarded-against.
Behavior / temperament:
Colorado River Toads are nocturnal and remain in hiding much of the time, but readily emerge for meals, and soon lose their initial shyness. Protected by size and powerful skin toxins, they often seem “confident” in captivity.
These engaging creatures should be handled only when necessary, and then with latex gloves so contact with skin toxins is prevented. Amphibian skin secretions may cause irritations when transferred to their owner’s wounds, eyes, or the mouth. As this species’ secretions are known to have severe hallucinogenic effects, and if ingested may prove fatal, they are suitable only for mature adults.
Colorado River Toads do well in groups if provided enough space and cover. A 20-30 gallon tank makes a good home for single adult. A mix of sand and cypress moss will allow them to burrow, but feeding should be via tongs or a large bowl to prevent substrate ingestion. Washable terrarium liners also work well, in which case cork bark rolls and plastic caves should be provided as retreats.
These hardy creatures fare best when kept at 75-80 F. They need only a simple water bowl, which should be changed daily. The cage should be sprayed daily, with overall humidity being kept below 40%. Chlorine and chloramine must be removed from water via liquid preparations available at pet stores.
A highly-varied diet is essential. Crickets alone, even if powdered with supplements, will not support long-term health. Earthworms, roaches, sow bugs, crickets, locusts, butterworms, calciworms and other commercially-available insects will all be readily accepted. Crayfish and the occasional pink mouse will help supply enough calcium. Most meals should be coated with a powdered Calcium/Vitamin D3 supplement. A vitamin mineral supplement may be used 2-3x weekly.
Captive breeding is not common except in large outdoor pools. A commercial rain chamber, or increased misting, may stimulate breeding behavior at almost any time of the year.
Gravid female toads deposit 500-8,000+ eggs on the water’s surface and among aquatic plants. At 76-82 F, the tadpoles hatch in 3-7 days, and transform into toadlets within 1 month. They may be reared on a diet of fish food flakes, commercial tadpole pellets, and par-boiled kale.
Written by Frank Indiviglio