May 14, 2024
Joe Kosack/Pennsylvania Game Commission
Allegheny woodrats are native to the Appalachian Mountains, but have been disappearing in recent decades because of forest fragmentation and other factors. A breeding program at the Maryland Zoo will be assisted by the Pennsylvania Game Commission and other partners to help restore populations throughout their range.
A rat species native to the Appalachian Mountains will be the focus of a new program to help populations recover in a number of states, including Pennsylvania, where the animal's survival has faltered in recent decades.
The Allegheny woodrat, one of several types of pack rats, has a more mouse-like appearance with a furry tail and larger head than most rats. The species historically had a range that spanned from southwestern Connecticut to northern Alabama and west to Indiana. Forest habitats throughout their range have been fragmented, and they've lost food sources to invasive species, as well as competition from other wildlife. A deadly parasite spread by raccoons also has been blamed for their decreasing numbers.
Pennsylvania's population of Allegheny woodrats has dropped by about 70% over the last 40 years, according to the Pennsylvania Game Commission.
To rebuild their stock in the wild, the game commission is teaming up with the Maryland Zoo and the Wildlife Futures Program at the University of Pennsylvania School of Veterinary Medicine. The organizations have started a captive breeding program at the Maryland Zoo, where a colony will be established and adjusted to the wild before they are released on their own.
The first of the Allegheny woodrats in the program is a female that was found in Mifflin County. Once in captivity, her handlers learned she was pregnant and she gave birth to three pups. Woodrats from Virginia and Indiana will brought to the Maryland Zoo to help breed future generations.
"Woodrat populations have declined so much that they have become isolated from one another," said Kate Amspacher Otterbein, the game commission's mammal recovery specialist. "That leads to low genetic diversity and eventually to inbreeding, which is yet another factor in population decline."
Woodrats forage and build large caches of food to survive winters. They are nicknamed pack rats because they collect all kinds of items, from shotgun shells to bottle caps. As adults, they weigh less than a pound and measure about 17 inches with their 8-inch tails.
To make sure the woodrats in the program are prepared to return to the wild, the Maryland Zoo staff is largely monitoring them using a nest box camera. This is to prevent them from forming any human attachments that might compromise their survival in the wild.
"We previously had Allegheny woodrats and were quite successful at breeding them, so I'm optimistic about having lots of pups to release into the wild," said Erin Cantwell Grimm, mammal curator at the Maryland Zoo.
The species is considered endangered in Indiana, Ohio, Maryland, New Jersey, and New York. It's a species of conservation concern in Pennsylvania, Virginia, Tennessee, Kentucky, North Carolina and West Virginia. The goal of the program is to increase populations throughout the range and prevent the species from being added to the federal endangered animal list.
