BirdAnalyst
Species · BCR 4 · BBS 2026 Release · 1966–2025

Common Loon In BCR 4

All regionsBCR 4Wetland birds

Common Loon in BCR 4 has fallen sharply: down 54% on the route-weighted index since 1983.

-54%Since 1983TrendPercent 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 →
41Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
44YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 →

Common Loon has fallen sharply in BCR 4: down 54% on the route-weighted index since 1983.

Common Loon In BCR 4 Population Forecast

If the recent trend holds, Common Loon in BCR 4 is projected to fall about 67% by 2030 — from 0.57 in 2025 to a central estimate of 0.19 (95% range 0.00–0.93). A 5-year backtest shows a typical error of ±78.7%, with 100% of held-out values landing inside the 95% band.

-67%Change by 2030TrendPercent 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 →
0.19Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.9395% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±78.7%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Common Loon in BCR 4 is projected to fall about 67% by 2030 — from 0.57 in 2025 to a central estimate of 0.19 (95% range 0.00–0.93). A 5-year backtest shows a typical error of ±78.7%, with 100% of held-out values landing inside the 95% band.19782030
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20260.260.001.0
20270.240.000.98
20280.230.000.97
20290.210.000.95
20300.190.000.93

Routes In BCR 4

Routes recording Common Loon in BCR 4.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
WillowALASKA92025
Skilak LakeALASKA41985
McgrathALASKA42022
TonsinaALASKA32018
Swan Lake RdALASKA32025
Lake LouiseALASKA32011
KuskulanaALASKA32024
KalifonskyALASKA22025
Chena Hot SpALASKA21986
WasillaALASKA21983
Seven LakesALASKA22025
Burma RoadALASKA22025
Moose CreekALASKA22016
Porcupine R.ALASKA22002
Ft. RichrdsnALASKA22023
Kanuti LakeALASKA22023
Galena (Short)ALASKA22025
Paxson LakeALASKA21997
Nabesna RoadALASKA22024
Mccarthy Rd2ALASKA22024
CircleALASKA12017
Birch LakeALASKA11993
SlanaALASKA12024
ChistochinaALASKA12008
MaclarenALASKA12016

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