Anaxyrus fowleri

The upper surface is brown, grayish, or rarely greenish or red, with a pattern of large dark blotches, the largest of which contain 3 or more warts. Usually there is a light stripe along the middle of the back. The hard ridges behind the eyes contact the patotoid glands (large glandular swellings behind the eyes). The parotoid glands are about twice as long as wide. Maximum snout-vent length is around 3.8 inches (9.5 cm); females grow much larger than males. Mature male can be recognized during breeding season by their dark throat and dark patches present on the inner surfaces of thefirst and second toes of the front feet. The male's expanded vocal sac is spherical or slightly elongated. Breeding calls are loud waaaaaah sounds lasting about 1-4 seconds and emitted up to several times per minute. Larvae are dark brown to black and often mottled. The eyes are positioned high on the head. The fins are mainly clear with sparse pigment flecks, with more in the upper fin than in the lower. Larvae reach a maximum total length up to around 1.1 inches (2.7 cm). Eggs are black above, tan below, 1.0-1.5 mm in diameter; they are deposited in long strings in a single jelly envelope, with single or double row of eggs in each jelly string.

Fowler's toads inhabit wooded areas, river valleys, and floodplains, including agricultural and residential areas, usually in areas with deep friable soils, up to at least several hundred meters from breeding sites. During cold weather or drought, they burrow underground or hide under rocks, plants, or other cover. Breeding sites include shallow water of marshes, rain pools, ponds, lakes, reservoirs, flooded areas, and other bodies of water lacking a strong current.

This and other toads have toxic skin secretions that help protect them from predation, but skunks and raccoons often eat them without ill effect by avoiding the skin and parotid glands. Hognose snakes (Heterodon) are immune to the toxins and swallow toads whole.

Breeding occurs in spring or summer (timing varies geographically), often after heavy rains. Male breeding choruses may last a few weeks. Individual females lay clutches of thousands of eggs in long strings. Larvae hatch within about a week and metamorphose into tiny toadlets in 1-2 months. Individuals become sexually mature in 2 years in Indiana (Breden 1988); 2 (males) to 3 (females) years in Connecticut (Clark 1975, Can. J. Zool. 52:1489-1498). At Long Point, Ontario, among 53 mature males, 14 were one year old, 25 were two years old, 13 were three years old, and 1 was 4 years old; possibly some one-year-old females were mature (Kellner and Green 1995, J. Herpetol. 29:485-489).