BirdAnalyst
Species · BCR 14 · BBS 2026 Release · 1966–2025

Chestnut-sided Warbler In Atlantic Northern Forest

All regionsAtlantic Northern ForestForest birds

Chestnut-sided Warbler in Atlantic Northern Forest has edged up: up 23% on the route-weighted index since 1968.

+23%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 →
155Routes 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 →

No notable trend signals for Chestnut-sided Warbler in Atlantic Northern Forest. See the full index history below.

Chestnut-sided Warbler In Atlantic Northern Forest Population Forecast

If the recent trend holds, Chestnut-sided Warbler in Atlantic Northern Forest is projected to fall about 42% by 2030 — from 14 in 2025 to a central estimate of 8.0 (95% range 3.9–12). A 5-year backtest shows a typical error of ±42.9%, with 0% of held-out values landing inside the 95% band.

-42%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 →
8.0Projected 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 →
3.9–1295% 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 →
±42.9%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, Chestnut-sided Warbler in Atlantic Northern Forest is projected to fall about 42% by 2030 — from 14 in 2025 to a central estimate of 8.0 (95% range 3.9–12). A 5-year backtest shows a typical error of ±42.9%, with 0% 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 →
20268.34.212
20278.34.212
20288.24.112
20298.14.012
20308.03.912

Routes In Atlantic Northern Forest

Routes recording Chestnut-sided Warbler in Atlantic Northern Forest.
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 →
DegrasseNEW-YORK412025
StoweVERMONT382024
East TroyMAINE372021
WanakenaNEW-YORK342025
LandgroveVERMONT302025
GaysvilleVERMONT302025
Northfld FlsVERMONT292025
MontereyMASSACHUSETTS262025
GreensboroVERMONT232025
HermonMAINE222021
Cummington 2MASSACHUSETTS222025
LempsterNEW-HAMPSHIRE222025
KasoagNEW-YORK222025
GlenNEW-HAMPSHIRE212025
East HavenVERMONT212025
CornvilleMAINE202025
HighmarketNEW-YORK202025
Dexter LakeNEW-YORK201975
HarmonyMAINE192025
PittsfieldMASSACHUSETTS192016
WalpoleNEW-HAMPSHIRE192025
S WallingfrdVERMONT192022
St JohnsburyVERMONT192025
MiddlesexVERMONT192025
HardwickVERMONT192024

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