Bird Conservation Region 4
BCR 4
An ecological region spanning Alaska, with 70 survey routes. BCRs are the natural unit for bird trends.
What Is Moving Here
long arc declinecomputed index
Glaucous Gull has collapsed in BCR 4: down 100% on the route-weighted index since 1991.
long arc increasecomputed index
Greater White-fronted Goose has surged in BCR 4: up 608% on the route-weighted index since 1991.
long arc declinecomputed index
Glaucous-winged Gull has collapsed in BCR 4: down 99% on the route-weighted index since 1982.
long arc increasecomputed index
Red-breasted Nuthatch has surged in BCR 4: up 587% on the route-weighted index since 1994.
long arc declinecomputed index
Lapland Longspur has collapsed in BCR 4: down 98% on the route-weighted index since 1986.
long arc increasecomputed index
Red-breasted Merganser has surged in BCR 4: up 382% on the route-weighted index since 1991.
How Guilds Are Faring
Survey Routes
Species By Family
Hawks, Eagles & Kites Accipitridae
Larks Alaudidae
Kingfishers Alcedinidae
Ducks, Geese & Waterfowl Anatidae
American Wigeon +224%Barrow's Goldeneye -73%Bufflehead -38%Canada Goose -25%Common Goldeneye -4%Common Merganser +320%Greater Scaup -82%Greater White-fronted Goose +608%Green-winged Teal +100%Harlequin Duck +49%Lesser Scaup -44%Long-tailed Duck -87%Mallard -78%Northern Pintail -61%Northern Shoveler -51%Red-breasted Merganser +382%Ring-necked Duck +15%Trumpeter Swan +133%Tundra Swan +63%White-winged Scoter -22%
Waxwings Bombycillidae
Longspurs & Snow Buntings Calcariidae
Treecreepers Certhiidae
Crows, Jays & Magpies Corvidae
Cranes Gruidae
Swallows & Martins Hirundinidae
Shrikes Laniidae
Gulls, Terns & Skimmers Laridae
Wagtails & Pipits Motacillidae
Osprey Pandionidae
Wood-Warblers Parulidae
New World Sparrows Passerellidae
Leaf Warblers Phylloscopidae
Woodpeckers Picidae
Grebes Podicipedidae
Sandpipers & Allies Scolopacidae
Skuas & Jaegers Stercorariidae
Owls Strigidae
Thrushes Turdidae
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.