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Species · BCR 2 · BBS 2025 Release · 1966–2024

Common Loon In BCR 2

All regionsBCR 2Wetland birds

Common Loon in BCR 2 has surged: up 89% on the route-weighted index since 1988.

+89%Since 1988TrendPercent 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 →
14Routes 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 →
36YearsYears 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 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 Loon has surged in BCR 2: up 88% on the route-weighted index since 1988.

Common Loon In BCR 2 Population Forecast

If the recent trend holds, Common Loon in BCR 2 is projected to fall about 63% by 2029 — from 1.6 in 2024 to a central estimate of 0.58 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±50%, with 80% of held-out values landing inside the 95% band.

-63%Change by 2029TrendPercent 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 →
0.58Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–1.495% 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 →
±50%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 2 is projected to fall about 63% by 2029 — from 1.6 in 2024 to a central estimate of 0.58 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±50%, with 80% of held-out values landing inside the 95% band.19852029
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 →
20250.580.001.4
20260.580.001.4
20270.580.001.4
20280.580.001.4
20290.580.001.4

Routes In BCR 2

Routes recording Common Loon in BCR 2.
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 →
Cape NomeALASKA92024
DillinghamALASKA52019
Cold Bay (Short)ALASKA41992
King SalmonALASKA32023
Cold BayALASKA22024
Katmai N.P.ALASKA12019
ChiniakALASKA12024
Kodiak 2ALASKA12024
CouncilALASKA12024
NomeALASKA12003
St. Mary'SALASKA12014
Togiak RiverALASKA12005
Gweek RiverALASKA11998
Goodnews BayALASKA12002

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.