By Emily Southgate, Virginia Native Plant Society
Do you know whether bald eagles breed in Loudoun County? Or, in what part of the county you might look to find an osprey, far from the coast? For the past five years a tireless team of 85 birders devoted 5,900 hours watching birds in the county for evidence that they are breeding, and sending the information to the Loudoun County Breeding Bird Atlas.
These birders reported that bald eagles breed in numerous places in the county, and that ospreys frequent many Loudoun lakes. They confirmed that 104 species of birds breed in the county, with another 13 probably breeding
and three more possibly breeding (seen at the right time with no evidence of breeding). They also noted non-breeding birds that spend the winter in Loudoun and migrating birds that pass through on their way elsewhere, adding 143 species to the total reported, for a grand total of 263 species of birds tallied in the county over the past five years.
This “citizen science” project provides data to the United States Geological Survey, for comparison with historical data and with information from other parts of the country that also do breeding bird surveys.
I surveyed two “blocks” of the county, each about 5 by 5 kilometers. I had birded informally most of my life, but this survey took birding to a new level. I did not just identify the bird, but also watched it for the tell-tale signs that it was actually raising, or trying to raise, a family. A bird seen in its appropriate breeding habitat when it was very unlikely to be migrating was a “possible” breeder. More evidence, such as singing from the same perch for a week or more, moved it into the category of “probable” breeder. Most exciting was finding evidence, such as building a nest, defending its nest (sometimes by trying to drive me away) or feeding its young, that qualified it as a “confirmed” breeder. Finding this kind of evidence required watching the birds carefully, even quietly following them to nesting sites.
My first confirmed breeder was a Carolina wren with a nest in my neighbors’ gas grill. They waited patiently until the nestlings were gone before doing any grilling. My second was a great-crested flycatcher with a
nest in the end of a dead branch in the woods. I was sure that downy woodpeckers, titmice and chickadees bred near my house, but I did not know where. Walking down a path one day, I was chased by a chickadee, so looked back to see where it went. Soon, it popped into a hole in a tree that I had passed several times before noticing the nest. When the parent popped in, I could hear its young chirping. At the end of my driveway, a family of downy woodpeckers made their home in a hole in a tree, and a family of titmice was nesting nearby in another tree.
From comparing the atlas data with data collected 20 years ago, we can see that field birds, such as bobwhite quail and meadowlarks, have declined in the county, while others such as bluebirds and bald eagles, have increased—the bluebirds most likely because of the installation of bluebird houses throughout the county, and the eagles from the 1972 ban on DDT and the protections of the federal Endangered Species Act. Scientists will be scrutinizing the results over the next few years to see what they can find about causes of increases and declines in numbers and species, to better understand changes in habitat and other environmental factors.
For more information about the Breeding Bird Atlas, contact the Loudoun Wildlife Conservancy at loudounwildlife.org.
You can find a preliminary analysis of the data here.
Citizen science projects like this one are a great way to get to know your county better, to contribute to understanding our environment, and to meet like-minded people. There are many opportunities, such as monitoring bluebird boxes, streams, and amphibians. Loudoun Wildlife Conservancy sponsors a wide variety of programs, providing training and direction. Goose Creek Association can always use more volunteers to help with its stream monitoring program. The data are collected according to strict protocols so that they can be used by scientists to study our environment. Get involved and learn more about your county and its environment.
[In Our Backyard is compiled by the Loudoun County Preservation and Conservation Coalition. To learn more about the organization or to participate in the rural road initiative, go to loudouncoalition.org.]