Allegheny Woodrat - Causes and Management of Decline

Causes and Management of Decline

In parts of their range (New York, New Jersey, and Pennsylvania), the Allegheny woodrat population has been in decline over the past thirty years. They have been extirpated from Connecticut, New York and parts of Pennsylvania, New Jersey and Maryland.

The reasons for the decline are not yet entirely understood but are believed to involve a combination of factors. The first reason is a parasite, the raccoon roundworm, Baylisascaris procyonis, which is almost always fatal to woodrats. Raccoons easily adapt to environmental change, and have thrived in the traditional woodrat habitat, increasing infection by the parasite, which enters woodrats because they eat the plant and seed material in raccoon feces. Another frequently cited cause is severe defoliation of American chestnuts caused by chestnut blight and of oaks by an invasion of gypsy moths (lowering available supplies of acorns for woodrats). Predation by great horned owls has also been cited. Finally, increased human encroachment causes fragmentation and destruction of the woodrats' habitat.

Indiana's Nongame and Endangered Wildlife Program currently monitors status, distribution and population. They are also conducting field searches for new localities and research to identify the factors for decline.

New Jersey's Division of Fish and Wildlife's Endangered and Nongame Species Program supported research by Kathleen LoGiudice. She developed a drug to be distributed through bait that the raccoons would eat, disrupting the growth and shedding of the roundworm parasite for about three weeks, effectively reducing the deposition of roundworm eggs near woodrat nesting sites and therefore reducing the threat of the parasite in woodrats.

Pennsylvania is conducting a three year study partially funded by a Game and Commission State Wildlife Grant and being led by Indiana University of Pennsylvania in an attempt to shed light on the daily and seasonal movements of woodrats, identify high quality woodrat habitat, and learn whether providing food caches can boost a population. Their work will include radio-telemetry, DNA profiling and mark-recapture trapping.

Maryland's Department of Natural Resources conducts trappings and surveys to study the woodrat's habitat.