Incilius alvarius

Colorado River Toad

Even deserts have toads: this one is closely tied to moist nights.

Reference photo, not the individual on display. Credits appear below.

Care commitment Specialist setup

Habitat Ground & cover

Visiting Observe only

Meet your new acquaintance

Nickname Desert Rain-night Wanderer

Nocturnal ground dweller · uses cover

Species highlights

White bumps at the jaw corners

Prominent glands behind the eyes and pale wart-like structures near the jaw are parts of the toad’s body, not merely rough decoration.

Skin secretions can contribute to chemical defence. Recognising normal structures also helps separate anatomy from any new change requiring assessment.

Defence belongs beside rain-night activity, underground shelter and water balance. Together these explain a desert amphibian more fully than a single “toxic” label.

Feature sources:

Arizona-Sonora Desert Museum · Sonoran Desert Toad

At a glance

The Colorado River or Sonoran Desert toad, Incilius alvarius, is a true toad from the southwestern United States and northwestern Mexico, not a spadefoot. It is often active at night and during suitable periods after seasonal rain, sheltering underground through dry conditions.

Seasonal rain and long dry periods shape activity. Underground shelter, suitable feeding nights and water-linked breeding show that tolerance often involves avoiding extremes.

A broad head, visible eardrums, prominent glands behind the eyes and pale jaw-area bumps offer useful observations. The skin is both an environmental interface and part of its defence. Water access, activity timing and shelter connect this anatomy with life in an arid landscape.

Common names Colorado River Toad; Sonoran Desert Toad; Incilius alvarius; Bufo alvarius; American spadefoot toad (former site label)

Scientific name Incilius alvarius

Native rangeSonoran Desert and nearby areas of the southwestern USA and northwestern Mexico

Adult sizeAdults can reach about 18–20cm body length, excluding limbs

ActivityMainly nocturnal; often concealed in dry periods

Diet Base feeding on varied, appropriately sized, gut-loaded invertebrates with supplements matched to condition and lighting. Avoid frequent energy-rich vertebrate meals and hand-feeding.

Habitat & care

Plan digging space and moisture choices for a large terrestrial toad; a desert origin does not remove its need for water.

Values guide routine care, not breeding or brumation. Dimensions are length × width × height for one adult unless stated otherwise; larger animals need more space.

TemperatureDaytime air 24–27°C Allow a modest night-time drop while retaining a cooler retreat and a choice of positions.

HumidityLocally 60–80% The breeder specifies this is not a fixed whole-enclosure or all-day target. Provide moisture choices, dechlorinated shallow water and dry resting areas.

LightingAbout 12h daylight Provide cover and a clear day–night cycle. If using gentle UVB, retain a fully shaded retreat.

Space120×60×70 cm Recommended starting size for one animal; provide digging substrate and accessible shallow water. Avoid mixing small individuals.

Look a little closer

Distinguish the round eardrum behind the eye from the raised gland farther back, then find the pale bumps near the jaw angle. At rest, watch small throat movements. During walking, compare forelimb support with the gathering movement of the hind limbs.

Care note: Skin and gland secretions are toxic. Avoid mouth and eye contact and keep other pets away; staff should use appropriate maintenance tools.

About this profile

The Colorado River toad is Incilius alvarius, a true toad in Bufonidae, distinct from Scaphiopus spadefoots.

Profile status: Reference profile · Reviewed 2026-10-20

References (4)

Photo: The former image was removed after the identity correction; a verified photo is pending.

Behaviour notes describe the species, not a promise about every individual. These care notes introduce its needs; ask our team about the animal on display and any supervised encounters.