BirdAnalyst
Species · BCR 12 · BBS 2026 Release · 1966–2025

Canada Warbler In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionForest birds

Canada Warbler in Boreal Hardwood Transition has surged: up 97% on the route-weighted index since 1968.

+97%Since 1968TrendPercent 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 →
102Routes 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 →
59YearsYears 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 →

Canada Warbler has surged in Boreal Hardwood Transition: up 97% on the route-weighted index since 1968.

Canada Warbler In Boreal Hardwood Transition Population Forecast

If the recent trend holds, Canada Warbler in Boreal Hardwood Transition is projected to fall about 27% by 2030 — from 1.5 in 2025 to a central estimate of 1.1 (95% range 0.68–1.5). A 5-year backtest shows a typical error of ±26.4%, with 40% of held-out values landing inside the 95% band.

-27%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 →
1.1Projected 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 →
0.68–1.595% 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 →
±26.4%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, Canada Warbler in Boreal Hardwood Transition is projected to fall about 27% by 2030 — from 1.5 in 2025 to a central estimate of 1.1 (95% range 0.68–1.5). A 5-year backtest shows a typical error of ±26.4%, with 40% 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 →
20261.10.661.5
20271.10.661.5
20281.10.671.5
20291.10.671.5
20301.10.681.5

Routes In Boreal Hardwood Transition

Routes recording Canada Warbler in Boreal Hardwood Transition.
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 →
LockportMINNESOTA202025
Sawbill LndgMINNESOTA202025
JordanMINNESOTA122025
Crane LakeMINNESOTA102025
CromwellMINNESOTA92025
Hart LakeMINNESOTA92025
EnsignMICHIGAN52010
BlackduckMINNESOTA52022
Red LakeMINNESOTA42012
ChisholmMINNESOTA42024
Walloon LakeMICHIGAN32004
BemidjiMINNESOTA31979
Sawbill CampMINNESOTA32025
Cass LakeMINNESOTA32016
ChaffeyWISCONSIN32025
HermanMICHIGAN22022
Maple GroveMICHIGAN21980
MuskallongeMICHIGAN22024
GilchristMICHIGAN22021
Lake CityMICHIGAN21985
FredericMICHIGAN21991
Red OakMICHIGAN22012
Hiawatha NfMICHIGAN22017
Scott'S MarshMICHIGAN22009
Sherry LakeMINNESOTA22022

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