BirdAnalyst
Species · BCR 10 · BBS 2026 Release · 1966–2025

Northern Waterthrush In Northern Rockies

All regionsNorthern RockiesForest birds

Northern Waterthrush in Northern Rockies has surged: up 353% on the route-weighted index since 1973.

+353%Since 1973TrendPercent 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 →
61Routes 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 →
54YearsYears 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 →

Northern Waterthrush has surged in Northern Rockies: up 353% on the route-weighted index since 1973.

Northern Waterthrush In Northern Rockies Population Forecast

If the recent trend holds, Northern Waterthrush in Northern Rockies is projected to rise about 81% by 2030 — from 0.35 in 2025 to a central estimate of 0.64 (95% range 0.29–1.00). A 5-year backtest shows a typical error of ±32.2%, with 100% of held-out values landing inside the 95% band.

+81%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 →
0.64Projected 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 →
0.29–1.0095% 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 →
±32.2%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, Northern Waterthrush in Northern Rockies is projected to rise about 81% by 2030 — from 0.35 in 2025 to a central estimate of 0.64 (95% range 0.29–1.00). A 5-year backtest shows a typical error of ±32.2%, with 100% of held-out values landing inside the 95% band.19702030
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 →
20260.620.270.98
20270.630.270.98
20280.630.280.99
20290.640.280.99
20300.640.291.00

Routes In Northern Rockies

Routes recording Northern Waterthrush 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 →
Inside RoadMONTANA112025
East Glacier ParkMONTANA102025
SulaMONTANA72024
Sullivan LkWASHINGTON71999
Libby DamMONTANA62025
EllistonMONTANA52025
Whitefish LakeMONTANA52024
Lolo PassIDAHO32019
GoldenIDAHO32010
NinemileMONTANA32025
Wise RiverMONTANA32025
St. Mary 2MONTANA32025
CusickWASHINGTON32025
Sullivan Lake 2WASHINGTON32023
PierceIDAHO22007
St MaryMONTANA22008
ArleeMONTANA22024
WoodmanMONTANA22025
ChestnutMONTANA22025
Thompson RivMONTANA22022
Painted RockMONTANA22022
Swan LakeMONTANA22025
Pagil GulchMONTANA22021
Clyde ParkMONTANA22022
Logan PassMONTANA22025

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