A Killdeer bird and her four unhatched eggs were protected during cleanup of an environmental restoration (ER) project at NAS Patuxent River’s former Outdoor Pistol Range in May.
The cleanup effort, a non-time-critical removal action (NTCRA), involved the excavation and stabilizing of a U-shaped berm that had been impacted with lead and copper from bullets fired during operation of the facility from 1943 through 1993.
As site cleanup began, however, ER contractors performing the NTCRA noticed a Killdeer nest with four eggs nestled in the middle of the site’s graveled entrance and immediately notified Heidi Morgan, NAVFAC environmental restoration program manager.
“I then notified my coworker, [Natural Resources Specialist] Jim Swift, who informed me the eggs couldn’t be moved because the parents would not look for or find them,” Morgan said. “The decision was made to rope off the area and work around the birds until the eggs hatched.”
The Migratory Bird Treaty Act prohibits the taking of any migratory bird without a permit from the U.S. Fish and Wildlife Service (USFWS). A “take” is not only the physical removal of a bird, but can also include harassment or the intentional destruction of a nest or young.
“The installation would have needed a permit to move the nest from the area and, in this case, I expected the USFWS to deny our request,” Swift said. “Additionally, it would’ve taken longer to apply for and obtain the permit than it took for the eggs to be incubated and hatch, which is about 25 days.”
Swift also considered the impact on the Killdeer, explaining that birds spend a lot of time and energy selecting and defending a nest site and laying and incubating eggs; and they know its exact location. If the nest is moved, they do not instinctively look for it, but instead assume it has been destroyed by a predator and move on.
While most birds nest above ground, Killdeer nest on the ground in areas with a lot of gravel, sand or stones.
“An average clutch size is four eggs and the young are ‘precocial,’ meaning they’re mobile and can move around within minutes of hatching,” Swift noted. “Once all the young have hatched, they’ll leave the nest and not return. That was also part of my reasoning for leaving the nest alone. The nest had been there for some time prior to its discovery, so the clock was already ticking on the incubation period.”
Another very important consideration given to the nest’s location was its potential as a Bird Aircraft Strike Hazard, particularly since the former pistol range’s site — at the intersection of Cedar Point and Sully Road — is near the approach to Runway 14.
“Adult Killdeer are not typically high flyers, instead they remain close to the ground, particularly with young to care for,” Swift said. “A survey of the nearby habitat determined that when the birds moved on from the nest location, they would relocate to an area offset from the runway, or to the shoreline of Pax River, further away from the airfield. Although the nest was near the runway approach, it was determined that leaving it would not increase the bird/aircraft strike risk.”
The nest was cordoned off with black and yellow tape and the bird parents cautiously observed as heavy equipment was delivered to the site, fencing was installed, and underbrush clearing began. If workers got too close, an adult Killdeer would jump up from the nest, tilt itself sideways, let one wing hang down as if it was broken, and limp away in its classic diversionary display meant to attract predators and lure them away from the nest.
“In the beginning, if you got too close to their nest, they’d sound off and pretend they had a broken wing, but after while they settled down and got used to us,” Morgan said “We named the mom ‘Angry Bird.’ To our surprise, on the day we were to begin excavating, the parents and eggs were gone; they had hatched over the weekend.”
The cleanup project is still underway. Approximately 3,000 cubic yards of soil will be excavated, screened for things such as projectiles, shells, casings and lead fragments, and then stabilized by adding Portland cement to the soil to reduce lead concentrations to acceptable levels before disposal off-base at an approved facility.
“After the impacted soil is disposed of, the site will be restored,” Morgan added. “Berms will be leveled and graded, and grass will be planted.”