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Species · BCR 10 · BBS 2025 Release · 1966–2024

Common Loon In Northern Rockies

All regionsNorthern RockiesWetland birds

Common Loon in Northern Rockies has edged down: down 23% on the route-weighted index since 1979.

-23%Since 1979TrendPercent 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 →
28Routes 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 →
45YearsYears 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 →

No notable trend signals for Common Loon in Northern Rockies. See the full index history below.

Common Loon In Northern Rockies Population Forecast

If the recent trend holds, Common Loon in Northern Rockies is projected to fall about 23% by 2029 — from 0.06 in 2024 to a central estimate of 0.04 (95% range 0.00–0.09). A 5-year backtest shows a typical error of ±53.4%, with 100% of held-out values landing inside the 95% band.

-23%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 →
0.04Projected 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 →
0.00–0.0995% 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 →
±53.4%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 Northern Rockies is projected to fall about 23% by 2029 — from 0.06 in 2024 to a central estimate of 0.04 (95% range 0.00–0.09). A 5-year backtest shows a typical error of ±53.4%, with 100% of held-out values landing inside the 95% band.19712029
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 →
20250.040.000.09
20260.040.000.09
20270.040.000.09
20280.040.000.09
20290.040.000.09

Routes In Northern Rockies

Routes recording Common Loon in Northern Rockies.
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 →
East Glacier ParkMONTANA32017
Inside RoadMONTANA32024
LaurierWASHINGTON32022
Pablo Res.MONTANA22016
Logan PassMONTANA22013
West ThumbWYOMING21982
Crazy WomanWYOMING22010
AlpineWYOMING21999
NaplesIDAHO11981
CascadeIDAHO11983
CabartonIDAHO12008
Libby DamMONTANA12015
KalispellMONTANA12013
St MaryMONTANA12008
ArleeMONTANA12024
Painted RockMONTANA11999
NoxonMONTANA12015
St. Mary 2MONTANA12024
Swan LakeMONTANA12024
Hebgen LakeMONTANA12024
KellerWASHINGTON11971
Twin LakesWASHINGTON12024
CusickWASHINGTON12000
CurlewWASHINGTON12013
Sullivan Lake 2WASHINGTON12015

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