BirdAnalyst
Species · BCR 4 · BBS 2025 Release · 1966–2024

Northern Waterthrush In BCR 4

All regionsBCR 4Forest birds

Northern Waterthrush in BCR 4 has held roughly steady: up 5% on the route-weighted index since 1976.

+5%Since 1976TrendPercent 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 →
63Routes 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 →
46YearsYears 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 Northern Waterthrush in BCR 4. See the full index history below.

Northern Waterthrush In BCR 4 Population Forecast

If the recent trend holds, Northern Waterthrush in BCR 4 is projected to fall about 20% by 2029 — from 16 in 2024 to a central estimate of 13 (95% range 4.2–22). A 5-year backtest shows a typical error of ±13.3%, with 100% of held-out values landing inside the 95% band.

-20%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 →
13Projected 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 →
4.2–2295% 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 →
±13.3%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 BCR 4 is projected to fall about 20% by 2029 — from 16 in 2024 to a central estimate of 13 (95% range 4.2–22). A 5-year backtest shows a typical error of ±13.3%, with 100% of held-out values landing inside the 95% band.19682029
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 →
2025133.922
2026134.022
2027134.122
2028134.222
2029134.222

Routes In BCR 4

Routes recording Northern Waterthrush 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 →
Anvik RiverALASKA1112024
Unalakleet RiverALASKA1072024
Mud RiverALASKA792024
Hather CreekALASKA622024
Goose BayALASKA461982
Nicholai SlALASKA382024
Koyukuk Riv.ALASKA322001
Galena (Short)ALASKA252024
Kobuk River (Short)ALASKA241992
Chena RiverALASKA201988
Kanuti LakeALASKA202024
PetersvilleALASKA192024
Bear CreekALASKA181991
RubyALASKA152024
ChistochinaALASKA142024
Hatcher PassALASKA132024
WasillaALASKA131983
Kenny LakeALASKA122024
Kanuti CanynALASKA122024
WillowALASKA112024
TatalinaALASKA102019
MatanuskaALASKA91983
CottonwoodALASKA81990
Mccarthy Rd2ALASKA82024
CircleALASKA72024

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