BirdAnalyst
Species · Vermont · BBS 2026 Release · 1966–2025

Northern Waterthrush Population Trend in Vermont

All statesForest birds

Northern Waterthrush in Vermont has surged: up 82% on the route-weighted index since 1969.

+82%Since 1969TrendPercent 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 →
23Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Northern Waterthrush Trends in VermontNotable 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 Vermont: up 82% on the route-weighted index since 1969.

Northern Waterthrush Population Forecast in Vermont

If the recent trend holds, Northern Waterthrush in Vermont is projected to rise about 44% by 2030 — from 0.17 in 2025 to a central estimate of 0.24 (95% range 0.00–0.58). A 5-year backtest shows a typical error of ±171.6%, with 100% of held-out values landing inside the 95% band.

+44%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 →
0.24Projected 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 →
0.00–0.5895% 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 →
±171.6%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 Vermont is projected to rise about 44% by 2030 — from 0.17 in 2025 to a central estimate of 0.24 (95% range 0.00–0.58). A 5-year backtest shows a typical error of ±171.6%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20260.240.000.58
20270.240.000.58
20280.240.000.58
20290.240.000.58
20300.240.000.58

Northern Waterthrush Survey Routes in Vermont

Routes recording Northern Waterthrush in Vermont.
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 Haven320251966
Hardwick220241968
Greensboro220081971
Marlboro119911970
North Pownal119761976
Stratton120241970
Landgrove120211984
S Reading120191976
Gaysville120042004
Post Mills120231975
Shaftsbury119791979
S Wallingfrd119881972
W Rutland120241979
St Johnsbury120042001
Northfld Fls120161980
Middlesex120131975
East Calais120151971
Newbury119901990
Hinesburg119921977
Colchester120191987
Newbury 2120162015
Stowe120101988
Bristol119961996

Northern Waterthrush Population Trend in Other States

alaskaconnecticutidahomainemarylandmassachusettsmichiganminnesotamontananew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiopennsylvaniarhode-islandvirginiawashingtonwest-virginiawisconsinwyoming

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