BirdAnalyst
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 HereNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Glaucous Gull has collapsed in BCR 4: down 100% on the route-weighted index since 1991.

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Red-breasted Nuthatch has surged in BCR 4: up 622% on the route-weighted index since 1994.

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Glaucous-winged Gull has collapsed in BCR 4: down 99% on the route-weighted index since 1982.

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Greater White-fronted Goose has surged in BCR 4: up 381% on the route-weighted index since 1991.

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Lapland Longspur has collapsed in BCR 4: down 98% on the route-weighted index since 1986.

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Common Merganser has surged in BCR 4: up 309% on the route-weighted index since 1987.

How Guilds Are FaringGuild trendA mean-index aggregate across the species in this group — the structural direction of the guild, with individual-species noise smoothed out.Full methodology →

-84%

Grassland birds

6 species
-81%

Seabirds

1 species
-77%

Birds of prey

16 species
-76%

Aerial insectivores

10 species
-71%

Waterfowl

20 species
-69%

Game birds

3 species
-67%

Wetland birds

17 species
-49%

Forest birds

38 species
-39%

Shorebirds

10 species
+41%

Generalists

3 species

Survey Routes

Species By FamilyTrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →

Hawks, Eagles & Kites Accipitridae

American Goshawk -57%Bald Eagle +19%Golden Eagle -72%Northern Harrier -59%Red-tailed Hawk -59%Rough-legged Hawk -5%Sharp-shinned Hawk -80%

Larks Alaudidae

Horned Lark -77%

Kingfishers Alcedinidae

Belted Kingfisher -69%

Ducks, Geese & Waterfowl Anatidae

American Wigeon +79%Barrow's Goldeneye -76%Bufflehead -32%Canada Goose -49%Common Goldeneye -22%Common Merganser +309%Greater Scaup -83%Greater White-fronted Goose +381%Green-winged Teal +72%Harlequin Duck +49%Lesser Scaup -46%Long-tailed Duck -87%Mallard -82%Northern Pintail -62%Northern Shoveler -72%Red-breasted Merganser +178%Ring-necked Duck +80%Trumpeter Swan +25%Tundra Swan +59%White-winged Scoter -43%

Waxwings Bombycillidae

Bohemian Waxwing -72%

Longspurs & Snow Buntings Calcariidae

Lapland Longspur -98%

Treecreepers Certhiidae

Brown Creeper -60%

Plovers & Lapwings Charadriidae

American Golden-Plover -97%Semipalmated Plover -87%

Dippers Cinclidae

American Dipper -51%

Crows, Jays & Magpies Corvidae

American Crow +84%Black-billed Magpie +95%Canada Jay +52%Common Raven +87%Steller's Jay -80%

Falcons & Caracaras Falconidae

American Kestrel -51%Merlin +16%Peregrine Falcon +263%

Finches Fringillidae

Pine Grosbeak -60%Pine Siskin -90%White-winged Crossbill +230%

Loons Gaviidae

Common Loon -54%Pacific Loon -66%Red-throated Loon +115%

Cranes Gruidae

Sandhill Crane +72%

Swallows & Martins Hirundinidae

Bank Swallow -84%Cliff Swallow -89%Tree Swallow -83%Violet-green Swallow +11%

Blackbirds & Orioles Icteridae

Red-winged Blackbird -57%Rusty Blackbird -51%

Shrikes Laniidae

Northern Shrike -83%

Gulls, Terns & Skimmers Laridae

Arctic Tern -78%Bonaparte's Gull -91%Glaucous Gull -100%Glaucous-winged Gull -99%Herring Gull -2%Short-billed Gull -40%

Wagtails & Pipits Motacillidae

American Pipit -92%

Osprey Pandionidae

Osprey +283%

Chickadees & Titmice Paridae

Black-capped Chickadee -53%Boreal Chickadee +110%

Wood-Warblers Parulidae

Blackpoll Warbler +48%Common Yellowthroat +163%Northern Waterthrush -20%Orange-crowned Warbler +54%Tennessee Warbler -76%Townsend's Warbler +43%Wilson's Warbler +20%Yellow Warbler -32%

New World Sparrows Passerellidae

American Tree Sparrow +217%Chipping Sparrow -11%Fox Sparrow -41%Golden-crowned Sparrow +18%Lincoln's Sparrow +87%Savannah Sparrow -67%Song Sparrow -97%White-crowned Sparrow -10%

Pheasants, Grouse & Turkeys Phasianidae

Ruffed Grouse +36%Spruce Grouse -56%Willow Ptarmigan -49%

Leaf Warblers Phylloscopidae

Arctic Warbler -59%

Woodpeckers Picidae

American Three-toed Woodpecker +61%Black-backed Woodpecker +385%Downy Woodpecker -37%Hairy Woodpecker -79%

Grebes Podicipedidae

Horned Grebe -89%Red-necked Grebe -78%

Rails, Gallinules & Coots Rallidae

Sora -37%

Kinglets Regulidae

Golden-crowned Kinglet +147%Ruby-crowned Kinglet +23%

Sandpipers & Allies Scolopacidae

Greater Yellowlegs -60%Least Sandpiper -65%Lesser Yellowlegs -26%Red-necked Phalarope -97%Solitary Sandpiper +39%Spotted Sandpiper +117%Upland Sandpiper -88%Whimbrel -61%Wilson's Snipe +87%

Nuthatches Sittidae

Red-breasted Nuthatch +622%

Skuas & Jaegers Stercorariidae

Long-tailed Jaeger -81%

Owls Strigidae

Boreal Owl -78%Great Gray Owl +31%Great Horned Owl -57%Northern Hawk Owl -40%Short-eared Owl -74%

Thrushes Turdidae

American Robin -26%Gray-cheeked Thrush -55%Hermit Thrush +62%Swainson's Thrush +8%Townsend's Solitaire +14%Varied Thrush -9%

Tyrant Flycatchers Tyrannidae

Alder Flycatcher -44%Hammond's Flycatcher +230%Olive-sided Flycatcher +25%Say's Phoebe -95%Western Wood-Pewee +96%Yellow-bellied Flycatcher 21×

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.