Potomac Valley bald eagles

By any measure, the recovery of the bald eagle in Maryland and the entire United States is a conservation success story. Nationally, the species was long endangered by DDT insecticide contamination, trapping and shooting.

Bob Cianflone photographed this bald eagle on the West Virginia side of the Potomac River, about a quarter mile north of Shepherdstown, several years ago. Before DDT was banned in 1972, the total bald eagle population in the lower 48 states had dropped to about 400 breeding pairs. At that time, Maryland had less than 50 pairs remaining in the entire state, with our region hosting a few nests along the Potomac River.

The Bald Eagle was removed from the Federal Endangered Species List in 2007, when the lower 48-state population total rose to about 10,000 pairs. In 2010, the eagle was removed from the Maryland state endangered species list. Today Maryland is home to over 500 nesting pairs, with the majority being found along the Chesapeake Bay and on the lower Potomac River.

The bald eagle continues to receive federal protection under the Bald and Golden Eagle Protection Act and the Migratory Bird Treaty Act. National guidelines for nest site protection have been adopted by the federal government and also apply to Maryland’s nest sites.

In our region, bald eagles are commonly seen near Harpers Ferry, West Virginia, and along the Potomac downriver from Harpers Ferry. There are well-studied nests located below Harpers Ferry and in Shepherdstown, West Virginia, across from Sharpsburg. You can go to the U.S. Fish and Wildlife Service NCTC eagle cam at http://outdoorchannel.com/eaglecam for a live-stream view of the Shepherdstown nest.

If the Shepherdstown nest is any indication, the local population is very healthy with one to three young eagles fledged most years. During the last two years there was evidence of fierce territorial competition as adult birds fought over the nest site to determine who would claim the huge nest structure located at the top of a 100-foot tall sycamore, active since 2006.

Bald eagles raised in the region usually remain in the same region their entire lives, as long as they have access to open water to feed on fish and occasionally waterfowl. The Chesapeake Region is an important stop for bald eagles migrating from other parts of North America during spring and autumn.

Reaching sexual maturity (and attaining a pure white head) at the age of 4 to 5 years, the bald eagle builds the largest nest of any North American bird and the largest tree nests ever recorded for any animal, up to 13 feet deep, 8 feet wide, and weighing over a ton. Birds mate for life and return to the same nests, adding plant material each year for decades, with the birds living 25 years or more.

During the winter, our region’s eagles are adding large sticks and fresh leafy material to make their nests ready for late January or early February egg-laying. The female, noticeably larger than the male, will lay one to three eggs that will be continuously incubated by both parents for 35 days, despite the harshest winter weather.

The young will be fed by both parents within the nest for about 11 to 12 weeks and after fledging will be given food away from the nest for another six weeks. The young learn to fly and catch prey completely on their own; no parental instruction is required.

Article by FCFCDB

Nature Notes for 2/8/2015