On the Wild Side!
E-Newsletter for the Chesapeake Bay Field Office

 

Delmarva Fox Squirrel Status is Improving

Delmarva fox squirrel. Photo by Megan Simpson, MES.
Delmarva fox squirrel. Photo by Megan Simpson, MES.

The Delmarva fox squirrel (Sciurus niger cinereus) was listed as federally endangered in 1967 because of a reduction in its distribution to only 10% of its historic range. Shortly after listing, the hunting season was closed. Translocations were initiated to establish new populations, expand the range and reduce the overall extinction risk. Sixteen translocations were conducted and 11 continue to be successful today, including Chincoteague National Wildlife Refuge and Prime Hook National Wildlife Refuge. They have always occurred and thrived on Blackwater National Wildlife Refuge.

Today, the range of the Delmarva fox squirrel is considerably larger as a result of these successful translocations and the discovery of new populations on the eastern edge of the range. In comparison to the time of listing, the squirrel’s range has increased from 4 counties to 10 counties; from occupying 10 percent of the Delmarva Peninsula to occupying 28 percent of the Peninsula. In addition to expansion of the range, it is persisting within the range as well. New sightings and camera surveys are documenting their continued persistence within the range and new areas that they now occupy.

The Chesapeake Bay Field Office has been working on a 5-year Status Review for the Delmarva fox squirrel. This is the second formal 5-year Status Review conducted. The previous 5-year review, conducted in 2007, concluded that the Delmarva fox squirrel was near recovery and the only remaining concern was the threat from timber harvest, though information regarding this threat was inadequate. The 2007 review recommended that status of the Delmarva fox squirrel be changed from endangered to threatened.

In trying to better understand habitat availability and potential threats, the Chesapeake Bay Field Office has worked with partners to analyze additional information on forest habitat using Light Detection and Ranging (LiDAR). This data enabled mapping of mature forest suitable for Delmarva fox squirrels. The LiDAR data indicate that there is unoccupied mature forest that is potential Delmarva fox squirrel habitat within the current range and in areas beyond the range and this provides habitat for continued range expansion.

This second Status Review will summarize the status of the populations, status of the habitat and analyze the threats posed by habitat loss from development, sea-level rise, and timber harvest. Biologists are looking at how each threat has affected Delmarva fox squirrels in the past 40 years and how these threats are likely to affect the squirrels in the next 20-40 years. The new Status Review is expected to be completed by summer of 2012.

Last updated: January 18, 2012