Protected Species in Pennsylvania: Allegheny Woodrat

What is it?

The Allegheny woodrat (Neotoma magister) is not so much a rat, as it is a mouse. It has a bicolor appearance and a furry tail, as opposed to other rat species. This nocturnal rodent can be easily identified by its large ears, eyes, and heavy head, along with elongated whiskers. The top portion of the body is gray in color and the underbelly and paws are white. It is usually 17 inches in length with an 8-inch tail and typically weighs less than a pound when fully grown.

The rat is typically found in rocky outcrops at higher elevations. The range of this species once extended from Indiana, south to the top of Alabama, and east to southwestern Connecticut. The range of the woodrat has fallen to 35% of the original distribution. The species is no longer found in Connecticut or New York and is declining populations in the other states where it currently resides. There are still sustainable populations found in southwestern, southcentral, and northcentral counties of Pennsylvania, with fragments in eastern counties.

Why was it listed?

Why these rat populations are declining is unknown, but experts suspect there are multiple factors working together to have a negative impact. One reason may be that predatory species like hawks and owls have been able to increase due to a general increase in prey from agricultural expansion, and this has put more pressure on the woodrat. Raccoon roundworm (Baylisascaris procyonis) has been found to infect the Allegheny woodrat. This pest invades the intestinal tract of its host which causes unusual behavior, fatal or severe nervous system disorders, and rupture of the intestinal tract. Food availability is also a possible cause of species decline. One of the main sources of food for the species was American chestnut (Castanea dentata). The loss of American chestnut from chestnut blight (Cryphonectria parasitica) may have caused a sharp decline in food availability and increased competition between the woodrat and other animals. Populations of the rat that are isolated due to development and habitat fragmentation have also been found to suffer from low genetic diversity (inbreeding) which can impact health and reproductive success.

What actions are being taken?

The Allegheny woodrat is listed as threatened by the Pennsylvania Game Commission, but it is not considered a protected species at the federal level. The Allegheny woodrat is also listed in the recent Pennsylvania Wildlife Action Plan (2015 to 2025). The actions outlined in this plan work to conserve the species by minimizing placing proposed roads, railways, windmills, mining/quarrying facilities, and oil/gas facilities within woodrat habitat or corridors; decrease or maintain low levels of raccoon roundworm infection within habitat or corridors; and increase the number of mast or nut-producing trees, such as reintroducing hybrid American chestnut. Conservation actions are focused on maintaining viable breeding populations in the Appalachian plateau, Ridge and Valley Province, and Upper Susquehanna River drainage in Pennsylvania. To help inform management actions, research is being implemented through three federal State Wildlife Grants Program projects. A model for predicting population size, determining age demographics, characterizing habitat, and tests for supplemental feeding are a few of the objectives of these grants. A genetic catalog of statewide woodrats will also be developed to help monitor genetic diversity within the remaining populations. Continuing surveys will help determine population fluctuations, raccoon roundworm infestations, or any other stressors, like human activity, on the woodrat.

Allegheny Woodrat conservation is also supported by a number of nonprofit and research organizations including the Nature Conservancy in Ohio and the Conserve Wildlife Foundation of New Jersey, both of which have active management projects with preserved habitat and monitoring programs. Delaware Valley University and Indiana University of Pennsylvania are also involved with monitoring programs associated with the Pennsylvania wildlife action plan. Some organizations even hold summer camps, providing greater opportunities for public outreach.

Why should we care?

Woodrats play an important role in shaping their ecosystem. As a small foraging rodent, they cache forest seeds and nuts, which if left too long can become a new forest, or at least a tasty snack for other chipmunks and squirrels. The Allegheny woodrat is also a fitting food source for important predators, such as owls and bobcats. Although the woodrat is a rodent, you should not expect it to cause home/property damage as it nests almost exclusively in rocky outcrops set far from the forest edge. Increased funding for monitoring and recovery of the woodrat can also support conserved landscapes and ecosystems more broadly.

Student Authors

This article was written in collaboration with undergraduate students as part of a class project at Pennsylvania State University.

References

Balcom, B., & Yahner, R. (1996). Microhabitat and Landscape Characteristics Associated with the Threatened Allegheny Woodrat. Conservation Biology, 10(2), 515-525. Retrieved March 24, 2021.

Butchkoski, E. (2014, September). Allegheny woodrat. Retrieved March 24, 2021.

Heffernan, Lindsey M. (2015). Pennsylvania Wildlife Action Plan. Pennsylvania Game Commission and Pennsylvania Fish and Boat Commission. SWAP-CHAPTER-1-apx14b-mammals.pdf (fishandboat.com)

Lombardi, J.V., Castleberry, S.B., Mengak, M. T., & Terrell, V. K. (2018). Natural and anthropogenic factors affecting Allegheny woodrat occupancy. Wildlife Society Bulletin, 42(4), 667-673.

Raccoon Roundworm (Baylisascaris). Michigan Department of Natural Resources, (2021), State of Michigan. Retrieved April 13, 2021, from DNR - Raccoon Roundworm (Baylisascaris) (michigan.gov).

Smyser, T. J., Johnson, S. A., Page, K. L., Hudson, C. M., & Rhodes, O. E. (2013). Use of experimental translocations of allegheny woodrat to decipher causal agents of decline. Conservation Biology, 27(4), 752-762. doi:10.1111/cobi.12064  

The New York State Department of Environmental Conservation. (2017, October 4). Species Status Assessment.