Eastern Spadefoot Toad

At first glance, the eastern spadefoot toad (Scaphiopus holbrookii) is relatively unimpressive. It is a small toad (1.75-3.0 inches long), with a white belly, a brown back that has two yellow stripes, and vertical pupils, but do not let first impressions fool you. Spadefoots are an incredibly unique toad found in southcentral Pennsylvania. Unlike most of Pennsylvania's amphibians, spadefoots live in dry sandy areas. Most amphibians would dry out and die in this environment, but spadefoots have several unique adaptations to overcome these obstacles. They are fossorial animals, meaning they spend most of their lives underground in a burrow. To help them dig, they have a small spur on their rear legs. When in the burrow, spadefoots curl up in a small ball and excrete a fluid that hardens the soil around them to help maintain their moisture. They also enter a state of torpor where they lower their metabolism. They only leave their burrows on rainy nights to feed. During these rare nights, they come out to eat beetles, millipedes, or any other small invertebrates they can catch. Their vertical pupils help them see at night.

Spadefoots do not have a traditional breeding season. Instead, they are explosive breeders; after a large rainstorm in the spring or summer, all of the spadefoots leave their burrows and breed. Spadefoots only breed in ephemeral, or temporary, bodies of water like ditches or flooded fields. They breed in these areas because there are no other amphibians that use them and no fish, which would eat their young. After a rainstorm, males attract females with a loud caw…caw, which has been described as sounding like a crow. This call can be heard a mile away. Females lay anywhere from 800 to 4,500 eggs per event. Spadefoots will breed up to three times a year, but if the weather does not cooperate, they may not breed at all in a year. Because spadefoots lay eggs in temporary bodies of water, eggs hatch rapidly—sometimes within a day of being laid. It does not take long for tadpoles to metamorphose; most will leave their body of water within 14 days. To fuel their rapid growth, tadpoles will eat almost anything from algae to their dead or dying siblings. Once a tadpole leaves the pond, it does not mature for another 15 to 19 months.

Unfortunately, the eastern spadefoot toad is in decline in Pennsylvania, and as a result, it has been listed as an endangered animal by the state. Because they are fossorial, spadefoots are particularly difficult to protect—the only way to survey for adult toads is for herpetologists to search for them on very rainy spring and summer nights. This makes it very difficult to estimate their populations and occupied habitat. The main threat to the spadefoot toads is habitat loss. Many of the areas they live in have been turned into suburbs. This often kills individual toads and destroys habitat. Their breeding habitat, which can be hard to identify, is also being lost to development. Roads, railroads, and highways have also been built across their habitat. This separates populations and can cut off potential habitat. Additionally, climate change may make their future more precarious, as Pennsylvania is predicted to be warmer and drier, which may make life harder for spadefoots. Protecting eastern spadefoot toads may seem difficult, but with a concerted effort, they can be saved.