Important Bird Areas

Yukon River Delta

Alaska

This expansive area includes the active (prograding) delta of the Yukon River from the mouth of the Apoon River west and south to Dall Point. It includes over 1,000 km of shoreline and encompasses three prominent physiographic regions: 1) the deltaic system fromed by the discharge of the main tributaries of the Yukon River, 2) a long segment of coastal graminoid meadow and non-vegetated intertidal flats to the south, and 3) two large embayments (Scammon and Kokechik bays) at the southern terminus having extensive intertidal flats, each protected from the Bering Sea by a series of barrier islands and sand spits. The active Yukon Delta segment is ringed by a 3-4 km wide band of mostly unvegetated intertidal mud and sandflats that integrate into extensive sedge/graminoid meadows that extend inland about 2 km to the most recent beach ridge. The central segment lacks the numerous distributaries common on the active delta, instead it is characterized by numerous shallow ponds and lakes.

Ornithological Summary

Yukon River Delta provides some of the finest waterfowl breeding grounds in Alaska. Most of the publications and onshore and offshore waterfowl surveys have been done for the IBA south of the Yukon River Delta, the Central Yukon-Kuskokwim (Dau 1987, Bowman et al. 2001).

Studies of shorebirds of this region are limited. Jones & Kirchoff (1977, 1978) spent two summers on the active delta during which they counted shorebirds along fixed transects. Over 10 census periods between 10 June and 28 August they reported an average density of 1,916 shorebirds/km2 on vegetated intertidal habitats (range 512-3, 184). The species composition changed during the course of the season, but 8 taxa accounted for most of the birds enumerated: Red-necked Phalarope (51%), Dunlin (14%), Long-billed Dowitcher (11%), Red Phalarope (8%), Semipalmated Sandpiper (7%), and Whimbrel (3%), and Bar-tailed Godwit (3%). Assuming this density occurred across similar available habitat, the population of shorebirds using intertidal graminoid meadows over just the mouth of the Yukon River exceeded 1.2 million birds. Considering the extent of non-vegetated intertidal habitats associated with this site (over 1,000 km2) and the numbers of shorebirds recorded on such habitat elsewhere on the Yukon-Kuskokwim River Delta coast (see Gill & Handle 1990), as many as 2-3 million shorebirds could use this site.

Until more recent data become available, however, this site is PENDING GLOBAL/CONTINENTAL status.

The Yukon Delta National Wildlide Refuge is recognized as being of Regional Importance by the Western Hemisphere Shorebird Reserve Network (WHSRN).

Total shorebirds: 2-3,000,000.

Years of surveys for shorebirds 1977 and 1978.

Shorebird seasons:
-Spring: Hudsonian Godwit, Red Phalarope
-Spring and summer: Western Sandpiper, Dunlin, Semipalmated Sandpiper.
-Spring, summer, and autumn: Red-necked Phalarope.
Summer: Rock Sandpiper, Black Turnstone, Common Snipe.
-Summer and autumn: Whimbrel
-Autumn: Long-billed Dowitcher, Lesser Yellowlegs, Black-bellied Plover.

Conservation Issues

Population growth and increased village wastewater disposal, disposal of trash (littering) and damage to fragile habitats related to access (by snowmobiles, three-wheelers and other vehicles) between villages, to allotments, and for resource harvesting activities.

Potential for increased consumptive use through hunting and fishing, as well as oil and gas development and mining activities.

Ownership

Native (50%), State of Alaska, Federal (35% - Fish & Wildlife Service, Yukon-Kuskolwim National Wildlife Refuge).

Habitat

River delta: large and small freshwater distributaries of the Yukon River; Intertidal mud/sandflats; vegetated intertidal; barrier island/bars; dwarf shrub meadows; inshore waters.

Shoreline-1,046 km
Barrier beach/spit-16 km2
Vegetated intertidal- 2,970 km2
Unvegetated intertidal- 1,059 km2

Land Use

Urban/industrial/transport.

Subsistence hunting and fishing.

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