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Species · BCR 4 · BBS 2026 Release · 1966–2025

Northern Waterthrush In BCR 4

All regionsBCR 4Forest birds

Northern Waterthrush in BCR 4 has edged down: down 20% on the route-weighted index since 1976.

-20%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 →
47YearsYears 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 rise about 107% by 2030 — from 6.0 in 2025 to a central estimate of 12 (95% range 3.5–21). A 5-year backtest shows a typical error of ±27.9%, with 100% of held-out values landing inside the 95% band.

+107%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 →
12Projected 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 →
3.5–2195% 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 →
±27.9%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 rise about 107% by 2030 — from 6.0 in 2025 to a central estimate of 12 (95% range 3.5–21). A 5-year backtest shows a typical error of ±27.9%, with 100% of held-out values landing inside the 95% band.19682030
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 →
2026123.221
2027123.321
2028123.421
2029123.521
2030123.521

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
PetersvilleALASKA472025
Goose BayALASKA461982
Nicholai SlALASKA362025
Koyukuk Riv.ALASKA322001
Kobuk River (Short)ALASKA241992
Galena (Short)ALASKA242025
Chena RiverALASKA201988
Kanuti LakeALASKA202024
Bear CreekALASKA181991
RubyALASKA182025
ChistochinaALASKA142024
WillowALASKA142025
Chena Hot Spring 2ALASKA132025
WasillaALASKA131983
Swan Lake RdALASKA122025
ColdfootALASKA122025
Kanuti CanynALASKA122024
TatalinaALASKA102019
MatanuskaALASKA91983
CottonwoodALASKA81990
CircleALASKA72024

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