A pair of black oystercatchers approaches decoys surrounded by a mat of monofilament nooses. Photo: Brian Guzzettii/USGS

Black oystercatchers at a winter roost site, Chiniak Bay vicinity. This area is the most northerly winter range routinely used by the species. Photo: Declan Troy/UFWS

If you’ve done much hiking along Kodiak’s rocky coastline, you’ve undoubtedly come across one of the islands’ more unique avian inhabitants. With an alarm call about as loud and raucous as any home security system, and dressed in black as if for mourning, the black oystercatcher is a common shorebird of Kodiak’s rocky shoreline. Unfortunately, in other portions of its range, the species isn’t doing as well. In fact, due to its small population (an estimated 11,000 birds) and restricted range, the black oystercatcher is regarded as a species of conservation concern. In Alaska the stakes are relatively high since about 70% of the entire worldwide population breeds along the state's southern coasts. Prompted by the need to better understand the species, this spring biologists with the U.S. Fish and Wildlife Service and Alaska Department of Fish and Game and their partners launched a rangewide study to determine habitat use and seasonal movements of black oystercatchers.

To date, a total of 18 satellite transmitters have been deployed on oystercatchers at three Alaskan sites (Middleton Island, Prince William Sound, and Stephens Passage) and an additional 19 VHF radio transmitters have been deployed on birds at the Pacific Rim National Park, Vancouver Island, BC and Kodiak’s Chiniak Bay. The Kodak effort led by Dave Tessler (ADF&G) and Brian Guzzetti (U.S. Geological Survey) and supported by Denny Zwiefelhofer and Nate Maryanski (Kodiak Refuge) resulted in nine oystercatchers  being captured and fitted with VHF radio transmitters. Researchers captured birds by setting up a pair of oystercatcher decoys surrounded by monofilament line noose mats. When recorded oystercatcher calls were played, resident birds flew in to investigate the decoy intruders and became tangled in the monofilament nooses. Researchers then untangled the birds, attached leg bands and radio transmitters, and release them.