More Wolf Spiders Are Eating American Toads

Posted on October 1, 2014

More wolf spiders are eating American toads according to a new study from researchers at the University of Georgia (UGA). This is because an invasive grass species has created a habitat that enables wolf spiders to thrive. The invasive grass species, called Japanese stiltgrass (Microstegium vimineum), has been spreading in parts of the southeastern U.S. since it was accidentally introduced in the early 1900s.

The image above shows a wold spider feeding on a toad. The wolf spiders increase in numbers in the tall stiltgrass because it enhances their ability to hide from predators, which include other wolf spiders. The stiltgrass seems to be an ideal habitat for wolf spiders but it is far from ideal for toads as they have to deal with a higher than usual number of predators. As the numbers of wolf spiders climb more and more of them prey on small toads. The researchers say, "The accumulation of large, predatory spiders in these invaded habitats then results in higher mortality for small toads that have recently emerged from wetlands."

The research was conducted by Jayna L. DeVore and John C. Maerz from the Warnell School of Forestry and Natural Resources at the University of Georgia The research paper can be found here in the journal Ecoloy.

DeVore says in a statement, "Spiders are actually tremendously important and incredibly abundant predators on the forest floor, and they will eat many of the small species that live there, so this effect is unlikely to only influence toads. And there are also other ways in which invasion by this Asian plant may influence species on the forest floor. We documented changes in invertebrate densities and soil characteristics that may affect other species that depend on these invertebrates for prey or are sensitive to changes in soil properties such as moisture and pH."

ANIMALS