IBA of the Month: Alsea Bay
Of the nearly 100 Important Bird Areas in Oregon, 14 are bays and estuaries--productive, dynamic, biologically-rich mixing zones of fresh and saltwater ecosystems. Birds abound where this tidally-influenced billowing occurs, and Alsea Bay is no exception. This over 2,500-acre IBA captures a full 5 of the 150 birding sites designated along the Oregon Coast Birding Trail, boasting high-value habitat for shorebirds, waterfowl, waders, pelicans, terns, raptors, as well as elk, deer, river otter and harbor seals. The estuary has also been identified as an Important Aquatic Bird Area to be surveyed as part of the Oregon Coordinated Aquatic Bird Monitoring Program, a joint effort organized by Klamath Bird Observatory. The area’s habitat diversity--open water, exposed mudflats, emergent salt marshes, aquatic beds, and the adjacent Siuslaw National Forest--provides outstanding avian habitat and associated birdwatching opportunities.
The Alsea River watershed drains approximately 475 square miles of land, and the estuary it feeds is considered one of the more pristine estuaries on the Oregon Coast, though anthropogenic impacts from deforestation, overgrazing, overfishing, draining and filling of wetlands, chemical pollutants, and diking practices have all taken their toll. Although Oregon Department of State Lands exercises authority over tidelands with a mandate to conserve water quality for human consumption, wildlife, fish, and aquatic life, it takes collaboration by conservation nonprofits, agencies, and private landowners to ensure estuary protection and restoration here.
An Alsea Bay Action Plan was written in 2004 to define conditions in a bay that has seen a 40-60% loss of intertidal habitat, and to identify conservation issues and set priority target areas. A number of conservation success stories have occurred around Alsea Bay since the penning of that Action Plan. Restoration of Lint Slough at the southwest part of the bay was identified as a top restoration priority, and dike and levee removal now allows for natural (pre-1963) hydrological function of the Slough. The Wetlands Conservancy (in cooperation with The Central Coast Land Conservancy, US Fish and Wildlife Service’s Coastal Wetlands Conservation Grant program and the Oregon Watershed Enhancement Board) has acquired 240-acres of high-priority estuarine marsh habitat along West Bayview Oxbow, as well as tidal marshlands and forested uplands along Starr Creek at the northeast end of the bay. The Siuslaw National Forest has also acquired a riparian old-growth forest parcel along the lower Drift Creek, which flows into the Alsea River just east of the bay. Restoration in this watershed goes a long way toward improving avian and salmonid habitat value in what was once the best coho salmon spawning river in the state!
Species of Ornithological Significance
Alsea Bay was nominated as an IBA primarily for substantial congregations of Caspian Tern and Brown Pelican, as well as for thousands of migratory shorebirds and waterfowl. Estuaries along the coast provide feeding and resting areas in spring and fall, relative shelter in winter, and feeding grounds for offshore nesting seabirds in spring and summer. Possible sightings at Alsea Bay by season are listed below.
October: White-fronted Goose, American Widgeon, Mallard, Ring-necked Duck, Brandt’s Cormorant, Double-crested Cormorant, Great Blue Heron, Great Egret, Belted Kingfisher, Common Merganser, Horned Grebe, Merlin, Bald Eagle, Black-bellied Plover, Black Turnstone, Least Sandpiper, Greater Yellowlegs, Western Sandpiper, Dunlin, and Ring-billed, California, and Western Gull.
Winter: Surf Scoter, Northern Pintail, Canvasback, Bufflehead, Common Goldeneye, Hooded Merganser, Greater Scaup, Red-breasted Merganser, Northern Pintail, Green-winged Teal, Common Loon, Pied-billed and Eared Grebe, American Widgeon, Ring-neck Duck, Pigeon Guillemot, Belted Kingfisher.
Spring: Surf Scoter, Greater Scaup, Bufflehead, Eared, Pied-billed and Western Grebe, Pelagic Cormorant, Mallard, Common Loon, Western Gull, Osprey, Bald Eagle, Pigeon Guillemot, Common Merganser, Brown Pelican, Greater Yellowlegs, Black Turnstone, Belted Kingfisher.
Summer: Pigeon Guillemot, Common Murre, Canada Goose, Mallard, Double-crested Cormorant, Great Blue Heron, Western Gull, Ring-billed Gull, California Gull, Osprey, Least Sandpiper, Greater Yellowlegs, Belted Kingfisher, Bald Eagle.
If you go
Visit the Oregon Coast Birding Trail website at www.oregoncoastbirding.com for more information on coastal birding sites or contact Mary Coolidge at 503.292.6855 x111 or mcoolidge@audubonportland.org for more information.
