Restoring the Allegheny woodrat population

Sep 26, 2013

There are some new faces on campus at Delaware Valley College this fall and they aren’t freshmen or transfers.

Two (1 male, 1 female) new Allegheny woodrats, arrived at DelVal in late August to add fresh, young blood to the breeding program at the College. The program is having some success and one of the captured females recently had a baby woodrat, which joined the College’s colony. DelVal received four more animals in September for a total of 2 males and four females.


Woodrats are experts in surviving in remote, rocky, forested areas, which makes them one of the best indicators of true wilderness. As the areas are developed, woodrat communities become deserted markers of what once was. Their populations provide a way for researchers to monitor unique and fragile ecosystems and their decline is considered a “red flag.” The Pennsylvania Game Commission is fighting this decline with the help of the captive breeding program at DelVal.

The partnership ties into the College’s focus on experiential learning and gives students in the conservation and wildlife management, zoo science and animal science programs a chance to observe an important conservation effort as undergraduates.

“This program provides a tremendous experiential learning opportunity for our students,” said Reg Hoyt, Delaware Valley College assistant professor and department co-chair for small animal science, conservation and wildlife management, and zoo science. “For zoo science, this is showing students how captive populations can fit in with conservation efforts in the wild.”

Classes will be doing projects related to the woodrats, but won’t be working directly with the animals. Student observers will help with the effort in a more hands-on way.  After a recent presentation, 32 students signed up to join the observation team.

The woodrat colony, after serving a similar role at Purdue University, was first brought to a DelVal lab on campus in June 2012. The colony’s main goal is to produce as many offspring as possible to support conservation efforts. Offspring may be used to augment declining woodrat populations, or re-establish colonies where they have been lost.

Pennsylvania is home to more than 5 percent of the world’s breeding population of woodrats and big population centers including those Dauphin and Franklin counties have been disappearing since the 1970s. Once found in 41 of Pennsylvania’s counties, they can only be found in a couple dozen or so mountainous counties today. The 20th century’s American chestnut blight and gypsy moth invasion — other imports from Asia — and substantial changes in land use have created huge habitat deficiencies and insurmountable barriers in the woodrat’s world.

Population centers today are usually surrounded by vast stretches of inhospitable and uninhabitable lands that they have little chance of traversing to reach other woodrat-friendly areas. It might take 20 to 50 years, over many generations, to shift just 20 miles to a new habitat if they need to leave an area. If the rats have to cross a valley, or an interstate highway or suburbia – where there’s no cover or food – but plenty of predators, “it’s like walking the plank.”

Since their populations are often stuck in concentrated communities, without access to other woodrat colonies, genetic diversity is a challenge to their survival. The breeding program at the College is aiming to strengthen colonies by adding new blood to these isolated colonies.

DelVal’s colony will include a maximum of 25 animals. Juveniles will be handed over to the Game Commission for release into the wild.

Release sites have not been finalized yet, but State Game Land 211 in Dauphin, Lebanon, and Schuylkill counties, as well as the Lehigh Gorge in Carbon County are possible options.