Delmarva Peninsula Fox Squirrel: Journey to Recovery

by Kathy Reshetiloff

Catching a glimpse of Delmarva Peninsula fox squirrels (Sciurus niger cinereus) was once rare within the forests of the peninsula connecting Delaware, Maryland, and Virginia. By the time it was protected as endangered under the Endangered Species Preservation Act in 1967, this large, silver-gray tree squirrel could only be found in a handful of counties on peninsular Maryland—just 10 percent of its historic range.

Now, after 45 years of coordinated efforts to boost populations and conserve habitat, the future looks bright for this fox squirrel. Today the squirrel’s range has increased to 10 counties, with a current population of up to 20,000.

The Delmarva fox squirrel, as it is more commonly known, can be found in the mature woodlands of mixed pines and hardwoods with a closed canopy and open understory. It thrives in the rural landscapes of the Delmarva Peninsula and is more likely to be found in the woods near farm fields than in suburbs.

The squirrel’s decline in the mid-1900s was fueled by the combination of factors. As forests were cleared for farms and development, the squirrel’s habitat decreased. In addition, timber harvests on short cycles decreased the amount of mature woodlands needed by the Delmarva fox squirrel. Over-hunting of fox squirrels may have also played a role in its decline.

Following its listing as an endangered species, federal and state biologists, with help from private citizens, began efforts to restore the species to a greater part of its historic range. Officials closed the hunting season, and biologists re-introduced animals to several large farms in Maryland, where populations continue to thrive today.

"We worked with several landowners who were more than willing to have squirrels on their property," said Glenn Therres, the associate director of Maryland Department of Natural Resources Wildlife and Heritage Service. "We have been monitoring the squirrels for many years now, and they have really done well."

Eleven of these successful translocation sites exist across the squirrel's range, and its distribution has grown to now cover nearly a third of the Delmarva Peninsula. While some of the forest occupied by the Delmarva fox squirrel is on federally or state-owned land, more than 80 percent of its home is on private land.

"The habitat provided by private landowners is supporting the majority of this species' distribution," said Therres. "And its ability to persist and thrive on the working landscapes of the Delmarva is now well documented."

Several re-introductions occurred on national wildlife refuges including Chincoteague and Prime Hook, and the source of the animals for many of these translocations was the Blackwater National Wildlife Refuge. Blackwater Refuge is in the heart of the Delmarva fox squirrel distribution, where these squirrels are very abundant and closely monitored and studied.

In addition to the translocations, the Delmarva fox squirrel population has also expanded into new areas on its own.

Delmarva fox squirrel sightings have been reported by state and federal biologists, as well as knowledgeable citizens who live, work, and hunt in the rural landscapes where the species occurs. These animals are not always easy to see but can be visible at times of the year along field edges, roadsides, or in the woods by hunters sitting quietly. These sightings, along with records from trapping and camera surveys – all mapped by the U.S. Fish and Wildlife Service’s (Service) Chesapeake Bay Field Office – document a larger range and healthier distribution for this species.

The Service’s most recent scientific evaluation of the Delmarva fox squirrel population, called a five-year status review, concludes with a recommendation to remove it from the federal list of threatened and endangered species. The Delmarva fox squirrel distribution is now much larger then when it was first given federal protection, with very good persistence within the range.

"Over 90 percent of the forest area that was occupied by Delmarva fox squirrels as of 1990 continues to be occupied 20 years later," said Cherry Keller of the Chesapeake Bay Field Office. "The analyses in the status review indicate that the Delmarva fox squirrel distribution is now sufficiently large and well distributed to withstand current and future threats. This is very good news for the squirrel."

Kathy Reshetiloff, a writer/editor in the Service’s Chesapeake Bay Field Office, can be reached at Kathy_reshetiloff@fws.gov or 410-573-4582.