As the Shenandoah River and Opequon Creek wind through the fields and forests of our beautiful Clarke County, it is easy to forget that the bucolic scenery that we so easily take for granted also plays important role in providing habitat for the many large bird species that visit our area each year. In fact, some of America’s largest birds are here right now, quietly at work, raising the next brood of chicks just as Nature has prescribed for thousands of years.
From a raptor’s birds-eye-view Clarke County must look like Heaven.
Bordered on the east by the Shenandoah River and the west by Opequon Creek, Clarke’s two major rivers are filled with fish while the wide pastures that lie between the streams provide long vistas that are perfect for snagging an unsuspecting mouse or snake.
And the trees here! Especially those massive sycamores that resist even the strongest floods that the Shenandoah can conjure up. Our massive trees provide the hands and arms that hold the twigs that hold the fledglings born here year after year.
It’s no surprise that big birds need big nests when you think about it. Afterall, the amount of work that it takes to build a big nest is, well, immense. That’s why the big nests aren’t really abandoned each year; they’re simply left with plans to return the following year.
Do the raptors that come here think about their nests as Clarke County summer homes?
Because the Bald Eagle (Haliaeetus leucocephalus) returns to the same nest site each year, their nests get big. Really big!
Bald eagle nests are among the largest nests of all birds. A typical Bald Eagle nest size is five to six feet in diameter and three feet tall. A famous Ohio nest used for 34 years measured almost nine feet in diameter, close to 12 feet tall, and weighed over 2 tons!
The Bald Eagle requires old-growth and mature stands of coniferous or hardwood trees for perching, roosting, and nesting. Selected trees must have good visibility, an open structure, and proximity to prey, but the height or species of tree is not as important as an abundance of comparatively large trees surrounding the body of water. Forests used for nesting must have a canopy cover of no more than 60 percent, and no less than 20 percent, and be in close proximity to water.
We’ve still have more than a few old trees in Clarke County that are big enough to support even the largest nest in the face of a spring thunderstorm gust. Sycamores and box elders five feet in diameter are not uncommon here, especially near streams.
There are even a few larger trees in our neck-of-the-woods here if you know where to look.
Similarly, Great blue herons congregate during the breeding season in rookeries for courtship, nest building, egg-laying and incubation, and chick-rearing. Like the Bald Eagle, Great Blue Herons re-use nest sites from the previous year, and rookeries will often grow in size over time.
Bald Eagles are sexually mature at four or five years of age. When they are old enough to breed, they often return to the area where they were born.
Clarke County has been producing Bald Eagles and herons for a long time.
It is thought that Bald Eagles mate for life. However, if one member of a pair dies or disappears, the other will choose a new mate. Bald Eagle courtship involves elaborate calls and flight displays. The flight includes swoops, chases, and cartwheels, in which they fly high, lock talons, and free fall, separating just before hitting the ground.
Bald eagles can spot a fish from hundreds of feet above water and can also spot prey at great distances when they are perched.
Scientists believe that eagles put sprigs of trees in their nests, is because the odor helps keep away parasites, such as blow flies. Eastern White Pine sprigs seem to be the eagles’ top choice. Parasites could weaken, or even kill, a young eagle.
While the Bald Eagle is perhaps the pinnacle sighting for avid birdwatchers, the Great Blue Heron is a more oft- spotted Clarke County guest and, in many ways, is no less majestic.
Great Blue Herons congregate at nesting sites in early spring and nesting occurs from February through late summer. Nesting sites, also called “rookeries” are located in proximity to prime feeding areas.
As feeding areas go, the Shenandoah River and Opequon Creek is way cool for big birds.
Great Blue Herons (Ardea herodias), due to their large size, graceful flight, and interesting feeding behavior, generate plenty of attention among the public. For many people, observing a Great Blue Heron is a memorable and meaningful wildlife experience.
From an ecological perspective, the Great Blue Heron, like the Bald Eagle, is a top predator in the food chain, and can serve as an indicator of habitat condition and food availability.
In Virginia, female Great Blue Herons lay from three to five eggs in March or April. Incubation, which is shared by both partners, starts with the laying of the first egg and lasts about 28 days. Males incubate during the days and females at night.
Once the eggs hatch, the parents immediately begin to feed their young, brooding them only during the first week. However, for another two weeks, one adult remains at the nest almost continually; during the day, the male watches the nest while the female hunts for food; at night the roles are reversed. After the first month, the pair spends most of its time outside the colony, returning only to feed the young and stand watch for short periods.
Young herons develop rapidly. At two weeks, between periods of sleep, they clean their plumage and often stand upright with their wings half-opened, and vibrate their elastic throat membranes in order to cool themselves. At six weeks, they no longer sleep much during the parents’ absence; instead, they prepare for their initial flight. They walk along the branches surrounding the nest, jump while beating their wings, or grasp a branch with their claws and try to raise it with the power of their wing beats. At eight weeks of age, the young fly clumsily from one tree to another, but always return to the nest to be fed.
Often a young heron will go to the wrong nest, which leads to fighting between the occupants and the intruder.
At about ten weeks the young herons leave their nest for good and are independent of their parents.
All large birds of prey are protected by federal law, as are their breeding sites. Penalties for harming or disturbing the birds are severe and can include fines and jail time.
As open spaces continue to be developed, especially in northern Virginia and throughout the Northern Shenandoah Valley, places where the wild things can live and thrive are becoming fewer and fewer. Last week a local farm suffered the loss of several goats, most likely due to attacks by coyotes. Late last year a black bear terrorized Berryville trash cans several nights in a row. Residents on the mountain take pride in sharing pictures of a local bobcat that eats from a house cat’s bowl left outside near the back door of a home on Blue Ridge Mountain Road.
Species compete. Over time some species thrive, others slowly disappear. Man, it seems, is the one species that always prevails.
But for now, Clarke County still has a little room left for the wild things.
View the Norfolk Botanical Gardens “Eagle Cam” The third egg hatched just a few days ago: