Bald Eagles in Winter at Mason Neck State Park

By Margarita Yatsevich

A woodpecker hammering, a crow’s hoarse call and a few song bird chirps: these were the sounds of winter solitude on a recent day at Mason Neck State Park in Lorton.

A small group of adults crossed the lawn by the park’s playground. They were dressed in coats and hats for the 40-degree weather. A solitary great blue heron rose from the ice near the shore and gracefully flew away toward the distant northern shore of Belmont Bay.

“We came for bald eagles.,” said bird watcher Scot Mcintosh. “There were none this time, but we saw a red-bellied wood pecker and a beaver den.”

Mason Neck State Park is home to the Elizabeth Hartwell Mason Neck National Wildlife Refuge, and is home to dozens of bald eagles.

“Sightings depend on the day,” said Kevin Koons, a naturalist at the park who leads interpretive programs on bald eagles. ”On windy days, like today, you can see from one to 15, with more in the morning and evening when they are fishing.”

Mason Neck State Park was founded thanks to two bald eagle nests spotted in 1965 on its present territory. After a series of land purchases by the state and the federal government, the park opened to the public in 1985. It sits on Mason Neck peninsula, which protrudes into the Potomac River. On its western side are Belmont Bay and Occoquan Bay and on its northeastern side is Gunston Cove. It shares the peninsula with several other protected areas, including Elizabeth Hartwell Mason Neck National Wildlife Refuge, Pohick Bay Regional Park and Meadowood Recreation Area.

Bald eagles frequent Mason Neck and the surrounding water, because fish is their staple diet.  

“Their diet is 90 percent fish,” said Koons.

Waterfowl, rabbits, turtles, snakes, other small animals and carrion (the flesh of dead animals) also could become part of an eagle’s meal. Koons said he and a colleague once carried out an experiment, to see how many eagles would come: they placed a dead deer, killed by a car, in a distant field of the park. According to their observations, only two bald eagles came. The rest were vultures.

Nancy Houser, an education specialist at Mason Neck State Park, said the park is a sanctuary for wintering bald eagles. She said the park’s bald eagle population consists of around 100 individuals. “We have five active nests. The eagles come back to the same nesting area. They mate for life” added Houser. The other bald eagles in the park are visitors, she said, attracted by the good fishing and less frozen waters off Mason Neck’s shores.

Koons explained that the visiting bald eagles like to roost on two particular trees during the night. These trees are out of sight in a place where no visitors are allowed.

Winter is the mating season of bald eagles. According to the US Fish and Wildlife Service, nest building in the Chesapeake Bay Region takes place in December and January; egg laying (one to three eggs) and incubation start in January and continue until the end of April; hatching and rearing of young take place from March to June; and fledging (learning to fly and leaving the nest) – from March to July. Nests can reach 10 feet in diameter and can weigh a half ton.

In winter, animals have different strategies to find food. Bald eagles congregate around bodies of water and look for prey from tall bare trees.

“It is much easier now for eagles to catch prey because you don’t have all the leaves present on the trees,” said Houser. “Three years ago everything was frozen. Bald eagles were down here on the ice, breaking holes in the ice to fish. There were 30-40 eagles out here,” Houser said.

Bald eagles are the symbol of US, but in the 1970’s they were in severe decline, due to food poisoning by DDT and lead, habitat destruction and overhunting, according to USFWS. Since 1973, when President Nixon signed the Endangered Species Act, the number of bald eagle pairs has increased from 800 to about 10,000 in 2007, when they were removed from the Endangered Species List. Mason Neck State Park had stopped surveying bald eagles three years earlier. David Stapleton, assistant park manager, explained that 10 years ago the bird’s population at the park was already stable.

Mason Neck’s personnel maintain a log of animal sightings, and anyone who has seen an animal is welcome to share, said Houser. In November, visitors spotted 11 bald eagles, in December – around 20, and about 10 in January. Houser said that more foxes have been seen lately.

This winter visitors have also reported seeing: red-tailed hawks, savannah sparrows and Bufflehead ducks, which spend the winter at Mason Neck State Park, but are from the ponds in the northern coniferous forests of Alaska and Canada. Visitors have also spotted opossum tracks and beavers, which had built a lodge in a marsh.

“Beavers are nocturnal, night time animals, so you don’t really see them until late in the day. It is the same thing with the opossum,” said Houser. Raccoons and skunks have been seen as well.

Several weeks ago a group of about 60 tundra swans were spotted at Kanes Creek, which flows into Belmont Bay.

“A week ago we had people tell us they saw 150 swans,” said Houser.

Mason Neck is also home to the Eastern box turtle, which is facing extinction, and to snapping turtles, she said, but because it is winter, they are buried in the mud and in a dormant state.

Houser said parks are important because they create opportunities for people to learn about plants and animals and become more in tune with nature. “Our technological and computerized world is missing the opportunity to be outdoors and learn about nature,” she said.

“People so much rely on computers and looking up things online that they are not getting out and actually experiencing nature,” she said. “When the connection is lost, people don’t care as much.’

Mason Neck State Park, like all state parks, is funded by tax dollars. Additionally, visitors pay a small entrance fee ($3 on weekdays and $4 on weekends) to finance maintenance and other work, like education.