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

Northern Waterthrush In Northern Rockies

All regionsNorthern RockiesForest birds

Northern Waterthrush in Northern Rockies has surged: up 433% on the route-weighted index since 1973.

+433%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 →
53YearsYears 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 433% on the route-weighted index since 1973.

Forecast

If the recent trend holds, Northern Waterthrush in Northern Rockies is projected to rise about 29% by 2029 — from 0.52 in 2024 to a central estimate of 0.67 (95% range 0.32–1.0). A 5-year backtest shows a typical error of ±18%, with 100% of held-out values landing inside the 95% band.

+29%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 →
0.67Projected 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 →
0.32–1.095% 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 →
±18%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 29% by 2029 — from 0.52 in 2024 to a central estimate of 0.67 (95% range 0.32–1.0). A 5-year backtest shows a typical error of ±18%, with 100% of held-out values landing inside the 95% band.19702029
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 →
20250.640.290.99
20260.650.301.00
20270.650.301.0
20280.660.311.0
20290.670.321.0

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 →
East Glacier ParkMONTANA182024
SulaMONTANA72024
Sullivan LkWASHINGTON71999
EllistonMONTANA62024
St. Mary 2MONTANA62024
Logan PassMONTANA62024
Wise RiverMONTANA52024
Whitefish LakeMONTANA52024
Swan LakeMONTANA42024
Inside RoadMONTANA42024
Lolo PassIDAHO32019
GoldenIDAHO32010
NinemileMONTANA32024
Sullivan Lake 2WASHINGTON32023
MivodenIDAHO22015
PierceIDAHO22007
Libby DamMONTANA22024
St MaryMONTANA22008
ArleeMONTANA22024
AugustaMONTANA22022
Thompson RivMONTANA22022
Painted RockMONTANA22022
Pagil GulchMONTANA22021
Clyde ParkMONTANA22022
Threemile WaMONTANA21993

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