Banded oystercatchers help scientists track shorebird recovery at Chincoteague Refuge

Linda Cicoira Photo.

By Linda Cicoira

The 14,000-acre paradise, known as the Chincoteague National Wildlife Refuge, where beach, dunes, and maritime forest stretch across Assateague and Morris islands, and include Wildcat Marsh, is a favorite place of 65 breeding pairs of American oystercatchers, some of which are monitored every half hour.

One such bird was recently walking along a parking lot fence, wearing a band on each leg and what appeared to be a backpack on its lower back just between its wings.

They aren’t listed as threatened or endangered under the federal Endangered Species Act, but they have experienced some population declines due to nest predators, habitat loss, and other disturbances. The bands and other apparatus help refuge workers monitor the birds.

The U.S. Fish & Wildlife Service lists oystercatchers as Birds of Conservation Concern, and most states identify them as Species of Greatest Conservation Need. In the Northeastern and Southeastern U.S., the oystercatcher is a priority species for the Atlantic Flyway Shorebird Initiative.

“The bands allow us to distinguish individuals,” said Keith Shannon, a spokesperson for Fish & Wildlife. “Each bird is given two identical color bands” that represent the state they were banded in. “Birds banded in Virginia are given black bands,” he continued. “This lets us tie behaviors, like breeding and foraging, to individuals.”

At Assateague, some oystercatchers “have a GPS tag that records where the bird goes every 30 minutes,” Shannon said. “At the refuge, this lets us see the bird’s habitat use, home range, and activity. Outside of the refuge, this lets us track their migration routes and non-breeding season movements, which can inform strategic conservation in the most important places.”

Female birds tend to be larger with longer, lighter-colored bills that are a bit more orange than red. Their backs are light brown. The males tend to be smaller with s shorter, redder bills and dark brown backs. Shannon said it is difficult to tell them apart.

“Our work with partners reducing nest predation … has demonstrated that focused conservation … to address threats to this species can be successful, and we are continuing to collaborate on strategic efforts to help this species rebound without the need for regulation,” Shannon explained.

Because the American oystercatcher is considered an indicator species for healthy coastal systems, efforts to conserve this species are good for other shorebirds, and for the resilience of coastal areas in general,” he said. “Nest monitoring occurs … from Maine to Florida — to track trends in breeding success and overall population health.