Scaphiopus holbrookii

Type: amphibian

Status: not ranked

Species Guide

Eastern spadefoot

Scaphiopus holbrookii

Species Type: amphibian

Conservation Status: not ranked

IDENTIFICATION

The eastern spadefoot is 1 ¾ to 3 inches in size. It is brownish, with two yellow lines that curve down the back from each eye. These two lines are usually obvious but they may be very faint in some individuals which have a high degree of melanism and are dark gray or almost black in color.

This species has large yellow eyes that protrude from its head and vertical pupils. There is a sharp, black spade present on each foot and the skin is fairly smooth for a toad, with a small number of tiny warts and no obvious parotoid glands.

The voice of the eastern spadefoot is an explosive, short, nasal grunt, repeated every few seconds – somewhat like a young crow’s squawk.

Tadpoles are up to 2 inches in length. They are brown on top, the belly skin and tail fins clearish, and the eyes are very close together on the top of the head.

 

Distribution & Habitat

This species occurs within the eastern U.S. from central Missouri and Louisiana in the west, through the Ohio River Valley to the Atlantic coast in the east, and as far north as southern New England and south to southern Florida.

Within New Jersey, this species is only found within the southern half of the state, although there is a historical record from Warren County.

They prefer forests or fields with sandy or loose soil and require temporary pools of water for breeding.

Diet

Adults consume small invertebrates while tadpoles will feed on small live and dead plant and animal matter. Tadpoles may prey on other amphibian larvae, including other spadefoots.

Life Cycle

The eastern spadefoot is active between the months of April through September. However, they have been known to stay burrowed underground, sometimes for years, only to emerge during after warm, heavy rains. They are explosive breeders – appearing suddenly, often in great numbers, after heavy rains. They don’t have a well-defined breeding season. Instead, they breed whenever heavy rains produce suitable breeding pools and temperatures are above 45 degrees Fahrenheit.

Eggs are laid in strings that may break apart, in masses of up to a few thousand eggs, and attached to plant material. Eggs laid during the summer hatch in one day, while eggs laid during colder temperatures may take two weeks or more to hatch. Tadpoles take as little as two weeks to metamorphose into the terrestrial form when conditions are warm and about eight weeks when it is cold.

The sharp-edged spade on each hind foot enables this toad to burrow vertically downward into sandy or loose soil. They burrow underground during the daytime and when conditions are cold or dry, but may be active both day and night during the brief breeding season. This species has been known to live up to 7 years in Florida.

Current Threats, Status, and Conservation

In 2016, the New Jersey Endangered and Nongame Advisory Committee recommended a Special Concern status for this species within the state, but no formal rule proposal has been filed to date. The Special Concern status is largely due to population declines and habitat loss. Pesticide use, diseases (such as Chytridiomycosis and Ranavirus), and climate change are also potential threats to this species.


HOW TO HELP

The Endangered and Nongame Species Program would like for individuals to report their sightings of eastern spadefoots. Record the date, time, location, and condition of the animal and submit the information by submitting a Sighting Report Form. The information will be entered into the state’s natural heritage program, commonly referred to as Biotics. Biologists map the sighting and the resulting maps “allow state, county, municipal, and private agencies to identify important wildlife habitats and protect them in a variety of ways. This information is used to regulate land-use within the state and assists in preserving endangered and threatened species habitat remaining in New Jersey.”

 

References

  • NatureServe. 2015. NatureServe Explorer: An online encyclopedia of life. Version 7.1. NatureServe, Arlington, Virginia. (Accessed: August 8, 2015).
  • Schwartz, Vicki. 2002. Field Guide to Reptiles and Amphibians of New Jersey. New Jersey Division of Fish and Wildlife.

Text written by Mike Davenport in 2016.

Scientific Classification

  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Amphibia
  • Order: Anura
  • Family: Scaphiopodidae
  • Genus: Scaphiopus
  • Species: S. holbrookii