Although Fairfax County saw slower growth than its neighbors in the past 10 years, at least one subset of the local population appears to be prospering: coyotes.
Neither the state nor Fairfax County has endeavored to officially count the coyote population, but local wildlife experts think their numbers are growing. And although state code classifies the animals as a nuisance, they might actually be providing some benefit to county residents.
Coyotes generally pose little or no threat to humans or property, and could help in keeping some overabundant animal populations -- such as rats, deer and geese -- down, according to Fairfax County Wildlife Biologist Vicky Monroe.
According to a recent report by the county's Environmental Quality Advisory Council, the Canada geese population in Fairfax County is increasing at about 15 percent annually and geese waste, a well-documented source of fecal coliform bacterial contamination, is a growing problem.
Overabundance of deer also is a cause of concern for many county citizens.
"Our forests are literally dying" because of overgrazing, Charles Smith, natural resources manager for the Fairfax County Park Authority, said during a September interview. In many of the areas selected for deer population management program, there are an estimated 100-plus deer per square mile, he said.
According to John Townsend of AAA Mid-Atlantic, Virginia is one of the top 10 states for all deer-related automobile accident claims filed annually nationwide.
"The average cost of a deer-related accident, including medical costs, is $3,000, according to the Insurance Institute for Highway Safety," he said. "There were 51,000 deer-related accidents in Virginia that accounted for $5 million in damage in 2009, according to insurance company State Farm."
Coming to Virginia
Although the migratory patterns that brought coyotes to Virginia are unknown, the Virginia Department of Game and Inland Fisheries reports the first sightings of the animals came as far back as 1983 in Rockingham and Washington counties, southwest of Fairfax. According to the National Park Service, the first recorded sighting of a coyote northeast of Fairfax -- in Washington D.C.'s Rock Creek Park-- was in 2004.
"We were in the process of doing deer management and inadvertently shot a photo of a coyote with an automatic game camera in Occoquan Regional Park," Monroe said of the first coyote reported in Fairfax in 2000. "We obviously weren't looking for one, so we were taken completely by surprise."
John Rohm, a wildlife biologist with Game and Inland Fisheries, said the eastern coyote in Northern Virginia most likely is the offspring of western coyotes that survived the several-thousand-mile migrations east and gray wolves that they bred with along the way.
"The result is that the eastern coyotes in Northern Virginia are significantly larger than the western coyote," he said. "Eastern coyotes typically weigh 30 to 50 pounds, are approximately 2 feet high at the shoulder, and are 4 to 5 feet long, approximately twice the size of the western coyote. Eastern coyotes also have longer legs and thicker fur."
"Right now there is nothing really limiting their population," Monroe said. "And one of their main food sources is deer, which we have plenty of."
Posing a threat?
Rohm warns that coyotes are not above eating a small dog or cat if extremely hungry, but such cases are rare. Coyotes also might get into pet food, garbage and bird feeder seeds.
"Coyotes eat rodents, rabbits, berries, fruits, carrion, and they possibly also eat the eggs of Canada geese," Monroe said. "Studies indicate that coyotes can account for up to 65 percent of fawn mortalities within a local population and they are the only midsized natural predator for the deer in this area."
Rohm added, "Coyotes have been known, in some cases, to prey on small domestic animals and scavenge through pet food left outdoors. It is always advisable to feed all pets indoors and to keep small pets inside or securely penned at night."
Although their numbers have not been chronicled, both Monroe and Rohm point to indirect evidence to support their claims of a growing coyote population.
"I would say that the coyote population in the county is actually growing, by virtue of the increased number of reported sightings that we have gotten over the last couple of years," Monroe said.
"Coyotes have no predators themselves -- other than cars -- and they have an abundance of food in this area," he said.
Monroe added that more and more reports of coyotes being hit by cars also seem to indicate greater numbers.