On a lovely spring evening on April 23, 19 enthusiastic people ventured out to Rust Library in Leesburg for Liz Dennison’s presentation on the “Dulles Greenway Eagle Cam: Window into the Life of Eagles.” Liz’s enlightening and entertaining presentation included information on development of the Dulles Greenway Wetlands and insight into past, present, and anticipated activities in and around an eagle nest located there, as observed through the Dulles Greenway Eagle Cam (DGEC). In addition to being a volunteer moderator and eagle expert on the DGEC team, Liz has worked for more than 15 years as a raptor rescuer, rehabilitator and educator. Liz began her work with birds of prey in 2006 with Raptor Conservancy of Virginia and continues that work today with Owl Moon Raptor Center. She founded Secret Garden Birds and Bees in 2016 to help raptors by caring for the sick and injured and educating the public on these amazing birds.
Liz Dennison.
Photo by Liz Len
The evening began with a video and discussion of the history of the Wetlands and installation of the eagle cam. The Wetlands comprises 149 acres of lush, protected land established in 1996 to replace the 64 acres destroyed in construction of the Dulles Greenway toll road. The DGEC includes two live cameras with microphones mounted more than 100 feet up in the branches of a Pignut Hickory tree where the subject nest is situated. DGEC team members zoom and move the cams to capture the events and beauty of the nest and its environs. The team also moderates various chats and social media sites associated with the nest as part of Loudoun Wildlife Conservancy’s outreach program.
Liz followed this with the history of Bald Eagle population decline from the widespread use of the insecticide DDT prior to its ban in 1972. In 1963, the population had reached an all-time low of 417 nesting pairs in the lower 48 states. DDT ingestion caused eggshell thinning, which made eggs too fragile to survive incubation or otherwise fail to hatch, leading to this drastic decline in the eagle population. Liz noted that DDT residue is still found in eagles today, more than 50 years after the ban. She discussed the slow but profound recovery of Bald Eagles, which has increased the current population to more than 316,000 eagles. In fact, by 2020, more than 3,000 breeding pairs resided in the Chesapeake Bay, which has the largest population of Bald Eagles anywhere except Alaska. In the 2023 Loudoun County Bird Count, 90 eagles were counted in one day in a 15-mile radius that includes the DGEC nest tree. Liz noted that we have never seen this kind of population explosion before. And, of course, with increased populations comes more conflicts and more competition for nests.
Liz then focused on the DGEC nest’s resident eagles and the array of wildlife seen and heard on the cams, including gray and flying squirrels, deer, Red-tailed Hawks, Barred Owls, racoons, coyotes, foxes, wild turkeys, heron, and a variety of birds, ducks, and geese, among others. She described methods used to detect physical characteristics and markings to differentiate and identify various eagles and noted that variations of plumage allow us to estimate the age of young eagles before they achieve their iconic adult plumage at five or six years.
Eagles had been observed raising their families in this tree for years before the cams were installed. Rosa and Martin (named for civil rights activists Rosa Parks and Martin Luther King, Jr.) were the resident couple at the nest when the cams were installed in 2021. Liz provided information, photos, and videos that captured the lives and activities of Rosa and Martin, including successfully raising their four eaglets, Orion (2022) and Pi, Pat, and Flora (2023). It was wonderful watching the eaglets through all stages of their lives on the nest—from tiny three-inch hatchlings to feisty three-foot tall fledglings—and seeing all of the care and attention their parents provided them! Rosa, Martin, and their offspring certainly captured the hearts and attention of many cam followers!
The rebuilt nest.
As this is a wild nest, nature can have a great impact, which Liz discussed and illustrated again with videos and photos. One such event was the incremental but catastrophic collapse of this huge, old nest before Pi, Pat, and Flora had fledged. Pat and Pi both fell from the nest during two different collapses. Both were rescued, rehabilitated, and released back to the Wetlands while Flora managed to maintain a perch in the tree and successfully fledged from the tree soon after the second collapse. Liz also described the successful efforts of Window to Wildlife (brought in by Loudoun Wildlife and Dulles Greenway) to build a base nest structure in June 2023 at the original nest’s exact location in the tree.
Liz discussed the return of Martin and then Rosa to this structure in September 2023, and the excitement of watching the couple work diligently and often comically to rebuild it to a complete and serviceable nest in the coming months. After all their work and bonding/mating activities, Liz described how everything looked to be on track at the nest until Martin’s disappearance as of December 2, 2023, just as nesting and mating season were starting to get underway.
Two potential suitors soon arrived on the scene and Rosa picked one, later named Lewis (after late Congressman John Lewis). Liz showed the interactions of this new couple, including Lewis’ prolonged and committed incubation of a round ham bone that ended up in the nest (likely the result of a meal gleaned from the nearby County landfill). Cam followers were entertained and encouraged by Lewis’ dedication to the ham bone. Along with his frequent delivery of meals for Rosa on the nest, they were encouraged that Lewis would prove himself a capable provider and co-parent.
When Rosa laid two eggs in mid-February, hopes for them were dashed when Lewis failed to help incubate the eggs or bring food to Rosa. Without Lewis’ help, Rosa was forced to leave the eggs untended in cold winter temperatures to find food for herself and then stopped incubating the eggs after nine days. Liz showed photos and described that last night on the nest, when Rosa arose from incubating the eggs to spend time looking down at them, seemingly pondering and making her decision. Lewis joined Rosa later that night and they both spent time on the nest, looking down at the eggs. In the early morning, Lewis flew away and Rosa flew off with him moments later, and we have not observed her since then. Liz vividly described these events and the sadness and confusion of the humans watching.
Lewis continued to visit the nest for awhile and Liz described the flurry of other adult male and female visitors that have shown interest in the nest and in each other, resulting in various courtships, mating, partner swapping, and territorial tussles. Many beautiful subadult eagles have visited the nest as well. Liz updated us on the current state of the nest, in which the latest frequent visitors include a female nicknamed “Lady” and a male nicknamed “New Visitor (NV).”
Liz concluded with a discussion of the threats that jeopardize Bald Eagles today. Avian Influenza has been present across the country for several years and is 100 percent fatal to birds of prey. Despite the success story after the DDT ban, manmade perils greatly threaten the health and lives of Bald Eagles, including lead poisoning (from lead bullets and fishing tackle), fishing line entanglement, collisions with vehicles, habitat destruction and electrocution from power lines. Liz noted that 80 percent of eagles requiring rehabilitation have significant lead poisoning levels, and that lead the size of a grain of rice can kill an eagle. Through education and reform, she hopes many of these dangers can be minimized and eliminated.
Liz concluded the evening with a question and answer session that generated further discussion about eagles and how Liz got involved with raptor rehabilitation. From her first involvement through her son’s school to her current work, Liz has learned and contributed to the welfare of Bald Eagles and all raptors that coexist with us. On this night, she certainly demonstrated that this is her passion and life’s work.
