Spadefoot (Scaphiopus holbrookii)
Order: Scaphiopus, Family: Pelobatidae
The spadefoot toad is a relatively moist, smooth-skinned amphibian.
It has a horny, broad black "spade" on its webbed hind feet, which it uses for burrowing.
Approximately 11/2 to 3 inches long, the spadefoot has large, bulgy eyes with vertical pupils. It is usually olive to brown in color with a pair of yellow stripes that extend from the eyes down the middle of the back.
II. GEOGRAPHICAL RANGE AND HABITAT:
- The spadefoot toad is a relatively moist, smooth-skinned amphibian.
- It has a horny, broad black "spade" on its webbed hind feet, which it uses for burrowing.
- Approximately 11/2 to 3 inches long, the spadefoot has large, bulgy eyes with vertical pupils. It is usually olive to brown in color with a pair of yellow stripes that extend from the eyes down the middle of the back.
- The spadefoot can be found throughout much of the U.S. eastern seaboard, from New England to Florida, and west to Ohio, Illinois, Missouri, Arkansas and Louisiana.
- It generally inhabits arid to semi-arid areas, such as sand dunes, fields, and woodlands with sandy or loose soils.
IV. LIFE CYCLE/SOCIAL STRUCTURE:
- Spadefoot toads eat a variety of insects, including termites, flying ants, crickets, caterpillars, flies, spiders, centipedes, millipedes, snails, earthworms and moths.
- The spadefoot's favorite food, the termite, is also an important source of nutrition for the species. Because they can reproduce for generations to come, termites are 200 times richer in fats and other nutrients than other insects.
- Spadefoots are dormant for most of the winter, emerging from their burrows at the start of the rainy season (usually March to October). To make it through hibernation, male spadefoots sometimes eat half their body weight in one feeding and then continue to live off this food while dormant. Reproducing females, however, must eat every two to three nights during dormancy.
- Tadpoles eat plants and small aquatic animals.
V. SPECIAL NOTES/ADAPTATIONS:
- Spadefoot toads are nocturnal and live in burrows.
- They spend most of their time underground, using the spurs on their hind feet to dig into the ground. Spadefoots are active at night throughout most of the summer, when they forage for insects.
- When the rainy season arrives, spadefoots emerge from their burrows and begin a breeding frenzy. Males move to a temporary pool of water, finding a spot that is deep enough, and begin to call for females.
- Reproduction occurs in the water, with male holding on to female's back with his sticky toe pads and depositing sperm over her eggs.
- The female lays her eggs (black, heat-absorbing embryos inside translucent jelly sacs) on plant stems in either cylindrical masses or in 1/4-inch bands held together by a thick, protective jelly, which helps keep them in place and repel possible predators.
- Eggs hatch between 24 hours and two days; larval stage lasts from two to nine weeks, with young able to become fully mature in less than two weeks.
- If the natal pool of water dries before the eggs metamorphose, the young die, but if metamorphosis occurs before the water dries, they have a chance to reach maturity.
- The first eggs to hatch release a hormone, slowing the maturation of the rest of the brood, which gives the early risers a competitive advantage. Regardless of size, hundreds or thousands of young can enter a population from the reproductive efforts of just a few dozen adults.
VI. POPULATION STATUS:
- The spadefoot has a section of capillary-filled skin in its pelvic region that helps it intake water. When the spadefoot needs water, it squats so that this area rests on the ground and absorbs water, even from apparently dry soil. Moreover, the toad's kidneys produce concentrated urea, which is stored in its enlarged bladder. As the spadefoot's body loses moisture (the species can lose 60 percent of its body weight in water during hibernation), the urea is released into the tissues to raise the concentration of body fluids. The concentrated urea in the skin tissues can pull moisture out of the surrounding soil and into the body.
- The spadefoot gets it name from the "spade" on its hind feet, which it uses to burrow.
- Choruses of singing spadefoots can sometimes be heard more than one mile away.
- Loss of habitat and breeding pools have contributed to a decline in spadefoot populations. It is a species of concern to conservationists.