Monitoring Shorebirds on Barrier Islands of
the Copper River Delta

Along coastal habitats of the Pacific Ocean, the majority of research on shorebirds has been conducted in protected waters such as bays and estuaries. In contrast, relatively little information exists on shorebird use of ocean beaches. The 80 km wide Copper River Delta is protected from the Gulf of Alaska by a series of barrier islands and spits. In 2005 and 2006, the Prince William Sound Science Center initiated the first comprehensive study of shorebird use of the Delta’s outer barrier islands.

Except for aerial surveys, field work took place at Egg Island, an uninhabited island located on the western edge of the Delta. A total of 30 shorebird species were recorded on the Egg Island outer beach and 24 shorebird species in the dune system (the uplands and wetlands between the primary and secondary dunes). In spring, migrating Sanderling were by far the most abundant species both on aerial surveys of the outer beaches and on beach transects at Egg Island. Transects in the dune system during spring were dominated by Pectoral Sandpiper and Least Sandpiper. Similar to the Delta’s mudflats, the most abundant species in the island’s estuary was Western Sandpiper.

Compared with spring, fewer shorebirds were recorded during southbound migration both at Egg Island and on aerial surveys of the Delta’s outer beaches. On the outer beach Least Sandpiper and Semipalmated Plover, both local breeders were the most abundant fall shorebirds.

We monitored breeding and post-breeding residency and movements by Semipalmated Plover and Least Sandpipers nesting on the dune system of Egg Island’s outer shore. For Least Sandpipers, typically breeding females left shortly after nest hatch whereas males remained until chicks fledged. Compared with Semipalmated Plovers, Least Sandpipers left earlier, with all marked birds gone by mid-July. Marked Semipalmated Plover adults were no longer sighted by the end of July, while marked chicks were observed through mid-August.

Principal Investigator:

Mary Anne Bishop, Ph.D

Prince William Sound Science Center

Cooperator:
Cordova Ranger District, Chugach National Forest

Funding:

Alaska Department of Fish and Game Nongame Program

Prince William Sound Oil Spill Recovery Institute

Full Report:

Bishop, M.A. 2007. Monitoring migrant and breeding shorebirds on barrier island beaches of the Copper River Delta, Alaska. Alaska Dept. Fish and Game Nongame Program Final Report.81pp.

ADFG Project T-1-16

Photos by Prince William Sound Science Center staff