Save the Woodrat!
While some wildlife ecologists are fighting to save the seals, the eagles, or the manatees, Richard Yahner and Betsie Balcom are saving the rats.
The Allegheny woodrat—a grayish brown rodent more mouselike than its name suggests—has been rapidly disappearing from the deciduous forests of the northeastern United States. In less than two decades, the woodrat has vanished entirely from New York, has declined quickly in Pennsylvania, and has been reduced to only one colony in New Jersey.
"The source of its demise cannot be identified," says Yahner, a professor of wildlife management at Penn State. "Without pinpointing a cause, it's impossible to stop its localized extinction."
Although called a rat, the Allegheny woodrat is quite a distant relative to the inner-city garbage-scavenging Norway rat. Acting the pack rat more than the pest, the woodrat is cuter, with its furry tail, larger ears, and white paws and underside.
"Because of its categorization as a rat, the public may not recognize it as a species that needs attention," says Yahner. "But wildlife ecologists view this as a serious issue that needs to be addressed." Finding a cause is crucial, he explains, since the woodrat's destruction line in Pennsylvania appears to be quickly sweeping westward.
As part of a two-year study, Yahner and Balcom are investigating some possible explanations for the woodrat's decline: the ingestion of a parasite found in raccoon feces, damage to oaks by acid rain and gypsy moths, or landscape changes. They have not yet directly linked any of these causes to the woodrat's mass disappearance, but they speculate that over the past four decades, woodrat habitats near natural rocky outcrops have become fragmented due to suburban development or agricultural practices. This fragmentation has possibly attracted larger numbers of the great horned owl, well-known for its ravenous appetite for rodents, including the infamous Norway rat. The researchers are currently inspecting the regurgitated animal carcasses eaten by great horned owls.
"By examining the undigestible remains of food, such as the feet, fur, and tails," Yahner explains, "we can determine if the woodrat has become a major food source for the owl."
Richard A. Yahner, Ph.D., is professor of wildlife management in the College of Agricultural Sciences, 107 Ferguson Building, University Park, PA 16802; 814-863-3201. Betsie J. Balcom is a graduate student in the Intercollege Graduate Degree Program in Ecology, 111 Ferguson Building, University Park, PA 16802; 865-1441. Their research is partially funded by the Wild Resources Conservation Fund. Reported by Lisa Rosellini. Vicki Glembocki is a former R/PS intern.