The California toad, Anaxyrus boreas halophilus, is a sub-species of Anaxyrus boreas, the western toad. It is native to most of the southern three-quarters of California including the northern part of Baja California. This toad is also found in western Nevada. Until 2005 it was classified as Bufo boreas halophilus, and many sources still use the older designation. The California toad is found at elevations from sea level to almost 12,000 ft (3,658 m) and in a variety of local climates and settings.
As with most toads, the female California toad is larger than the male. Females average 5 inches (about 13 cm) in length, while males average 3 to 4 inches(about 7.5 to 10 cm.) Both sexes have dry skin covered with the typical warts found on common species of toads. Colors vary but are usually a mixture of shades of gray and green, brownish red, yellows and tan. There is a black blotch surrounding each wart and a light stripe down the length of the back. The throat and underside are typically light yellow or creamy white.
California toads do not move quickly and are most often observed slowly crawling, or walking, with occasional hops. Their primary food source is insects, which they hunt by sight, and catch with their long, flexible, sticky tongues. The toads are also known to scavenge among debris at the edge of ponds and lakes.
During the coldest part of each year the toads seeks shelter in spaces in rocks or around tree roots. On occasion they also use abandoned rodent burrows. They emerge from shelter when the weather warms, usually after January. This is largely dependent upon location and elevation.
Breeding takes place soon after the toads emerge in the spring. Adults of both sexes congregate near bodies of water and fights may break out between males. The eggs hatch in three to ten days depending on the temperature of the water. Tadpoles grow to about an inch in length in the next 30 to 45 days, before metamorphosing, or developing, into adult form. A juvenile California toad reaches breeding age in four to six years.
The California toad co-exists well with humans and can be found in urban areas. It is found in most parts of its native range except deserts, and some high parts of mountain ranges. There are small populations in some wet locations within deserts but they are believed to have been introduced there by humans.