Scaphiopus holbrookii

The upper surface is brown, olive, gray, or blackish. A curved yellow line often extends from each eye and down the back. The pupil of the eye is vertically elliptical in bright light (like a cat's eye). A single hard sickle-shaped spade is on the inner underside of each hind foot. Maximum snout-vent length is about 2.9 inches (7.3 cm). Breeding males have black pads on the thumbs and inner toes of the front feet. Breeding calls are loud, nasal "quonk" or "wank" sounds, repeated every few seconds. Larvae are brown to bronze on top; the belly skin is clearish; the tail fins are clear; the tail musculature is not conspicuously spotted or blotched; and the eyes are very close together on the top of the head. Larvae are up to 2 inches (5 cm) in total length. Eggs are deposited in strings that may break apart, in masses of up to a few thousand eggs, attached to submerged plant material.

Eastern spadefoots occur in areas of sandy, gravelly, or soft, light soils in wooded or unwooded terrain. On land, they range up to at least several hundred meters from breeding sites. When inactive, they remain burrowed in the ground. Eggs and larvae develop in temporary pools formed by heavy rains. Breeding sites include temporary pools and areas flooded by heavy rains.

Eastern spadefoots do not have a well-defined breeding season. Instead, they breed whenever heavy rains produce suitable breeding pools and temperatures are above about 45 degrees (F). Breeding occurs often in spring or summer in the north but in any month in the far south (for example, recorded in February, March, June, September, and October in Florida) (Greenberg and Tanner 2004). Breeding aggregations in single pools include dozens to hundreds of adults. Individual females produce a clutch of up to about 2,500 eggs (in several batches). Eggs laid in summer may hatch in 1 day, whereas eggs laid in colder conditons may take 2 weeks or more. The aquatic larvae may form huge aggregations. They metamorphose into the terrestrial form in as little as 2 weeks when conditions are warm and in 8 weeks or more if it is cold (e.g., first emigration 16-29 days after breeding in Florida; Greenberg and Tanner 2004). Over a period of several years, individual breeding pools may produce metamorphs infrequently and at irregular intervals (Greenberg and Tanner 2005). In Florida, maximum lifespan was estimated to be 7 years (Greenberg and Tanner 2005).