On the Trail of Bluebirds: Monitors Keep an Eye on Loudoun Breeding Sites

Karla Etten fell in love with bluebirds when they began making visits to her backyard garden in Brambleton. That love affair has ramped up significantly in her role as the Loudoun County bluebird coordinator for the Loudoun Wildlife Conservancy, and for the Virginia Bluebird Society.

“I love the whole concept,” she said. “I’m an avid gardener, and seeing them in the garden, and growing berries and other plants that attract them, I thought it was great.” A neighbor started a Brambleton bluebirding club, and that’s what kicked off her career as a bluebird monitor nine years ago.

Female flying food LR         Etten now heads up the efforts of 75 volunteers who monitor the Loudoun Wildlife Conservancy’s 600-plus nesting boxes at bluebird trails throughout the county. They are charged with observing and recording data on bluebird activity during the breeding season. The conservancy has run the program for the past 10 years in partnership with the Virginia Bluebird Society.

Etten connected with Loudoun Wildlife Conservancy Executive Director Nicole Hamilton through the Virginia Bluebird Society. The trail monitoring is run as a partnership between the two organizations, Hamilton said.

Etten’s responsibilities include coordinating the monitoring of nests all over Loudoun, she said, from which data points are collected from 50 different sites, a mix of public and private hosts that include homes, farms, wineries, and schools. That endeavor to monitor the birds has grown from just one nest box a decade ago to more than 600 boxes.

Bluebirds have a lifespan of about three years in the wild, according to Etten. The first babies of this season have already hatched, in early May, and a second brood is on the way.

“A lot depends on the weather; we had such a cruel spring, so things got a bit delayed,” Etten said. And that makes a difference to the bluebird population, as it tends to fluctuate according to weather variations.

Eggs         The past two years were not kind to the bluebird population, according to data collected by the monitors, showing two very cold winters in 2014 and 2015, plus cool and rainy spring weather during the nesting seasons that is not good for hatchlings.

The total population last year was estimated at more than 740, way down from the 2014 count of 1,269. Last year’s milder winter and data so far show an increase in the population, but it may take a few years to get back to the 2013 count of 1,555, Etten said.

And it’s not just the weather that can be a problem. Bluebirds, even when safely ensconced in their nests or bluebird boxes, can fall victim to their most dangerous enemy—the common house sparrow.

“They’re the main concern for all natives. They’ll go into the nest box and attack the parent in the head, and do the same to the babies, also—it’s really quite gruesome,” Etten said of the non-native bird’s onslaught. Often, they’ll take the bluebird feathers to line their own nest.

Typically, the female bluebird will have three nestings. Usually at the beginning of the season she will lay about five eggs in a clutch, then fewer the next two times.

The male bluebird will come in to mark the nesting territory around the end of March, then the female comes in to set up home, so to speak. She will lay one egg per day, then brood until the hatchlings emerge in about 14 days.

“From then on we watch the nest. They usually begin to fly in about 21 days,” Etten said.

Female approaching LRToday, there are at least 75 bluebird monitors, who come from all walks of life and who live in all parts of the county, Etten said.

“Families, singles, children and youth, seniors, including lots of retirees, and people who like walking the [bluebird] trails. They’re people who are interested in helping provide stewardship for native cavity nesters,” Etten said.

She monitors a couple of nest boxes at her home, and she’s also looking to find more bluebird box hosts at farms and orchards around the county. Wineries also make a good site, she said, noting two of her best locales are at Sunset Hills Vineyard near Purcellville and at 50 West Vineyards near Aldie—both owned by Diane Canney.

Canney is an enthusiastic supporter of environmental sustainability, and works with the conservancy to support monarch butterfly gardens as well as bluebird houses through her solar-powered wineries, according to Sales Manager Matt Riley.

Riley said there are approximately 15 bluebird boxes at each vineyard. “We are dedicated to working with the Loudoun Wildlife Conservancy to help grow bluebird populations in our area,” he said. The 50 West nesting boxes are new this year, but Riley noted there was already activity in the spring. The two-year-old breeding program at Sunset Hills also has been successful.

And visitors appreciate the conservation efforts. “We try to create fun things, such as nature walks, and we take them around the vineyard—it ties in with our larger sustainability mission,” Riley said, noting western Loudoun is “a big area for wildlife—people here are so conservation minded.”

Etten has a few school sites, including the Middleburg Charter School and Briar Woods High School.

In addition to finding new sites, other needs include donated lumber from old sheds and barns, preferably cedar, Etten said. She’s also looking for volunteers to make the bluebird boxes.

Etten advises homeowners on ways to entice bluebirds to their yards. “Use native plants,” she said, noting homeowners can get their gardens certified as a native plant site. She also said that, for most the year, bluebirds only eat insects, and switch to berries in the winter.

Hamilton points out that to support a healthy birdlife, “you need a healthy habitat,” noting the monitoring partnership started as a way to engage people with wildlife, so they can see the connection between cavity nesters and their habitat. Increasingly, Hamilton said, the program looks at landscaping management, with a focus on avoiding pesticides and insecticides—which will kill off the insects vital for the birds. A study of the chickadee showed that the bird would have to get 5,000 insects to feed a single clutch of hatchlings.

Of her decade spent monitoring bluebirds, Etten said, “I continue to love doing it. There’s never a dull moment, I always come across something new.” And others feel the same way, sharing information, photos and posting questions on Facebook.

For more information on the monitoring program, go to loudounwildlife.org, link to Citizen Science and then to the bluebird tab.

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