Monday, May 25, 2009
The Eastern Woodrat
It's hard to get a lot of sympathy when I do a speaking engagement on NJ's endangered species for the eastern woodrat.
Unfortunately, eastern woodrats have been declining at an alarming rate throughout the northeastern portion of their range. The decline has been attributed, at least in part, to lethal infections of the parasite, raccoon roundworm.
The state's last remaining eastern woodrat Neotoma floridana population is at the Palisades Interstate Park in Bergen County.
A study of the raccoons at the Palisades revealed infection rates among raccoons to be relatively low compared to other areas where woodrats have disappeared. In 1998, observations found a growing woodrat population, possibly because the raccoon population had declined.
Woodrats typically live in rocky areas associated with mountain ridges such as cliffs, caves, talus slopes and rocky fissures. The rocky barrens where they den are generally devoid of vegetation with the exception of the occasional tree that manages to survive among the rocks.
Active primarily at night, woodrats leave the security of their rocky dens to visit adjacent areas to feed on the available vegetation.
In New Jersey, Allegheny woodrats occur in extensive talus fields at the base of
rock outcrops where the vegatation is birch, chestnut oak and the exotic paulownia (Paulownia tomentosa) trees found growing among the slopes of the Palisades.
Woodrats were considered extirpated in New York state by 1987 and surveys in Pennsylvania have shown that their numbers declined in the northeastern portion of the state and have disappeared from approximately one third of their former range there.
Back in 1984 and 1985, the Division of Fish and Wildlife’s Endangered and Nongame
Species Program conducted surveys of three historic sites and 16 sites that had suitable habitat. No animals were captured, although old sign was discovered at several sites.
The eastern, or Allegheny, woodrat was afforded protection under the New Jersey Endangered Species Act when it was added to the list as endangered in 1991.
The Palisades population has been monitored by live trapping since the mid-1980s. Trapping results between 1999 and 2001 indicate that this population has remained stable and may be increasing slightly.