BirdAnalyst
Species · BCR 13 · BBS 2025 Release · 1966–2024

Kentucky Warbler In Lower Great Lakes / St. Lawrence Plain

All regionsLower Great Lakes / St. Lawrence PlainForest birds

Kentucky Warbler in Lower Great Lakes / St. Lawrence Plain has declined: down 26% on the route-weighted index since 1971.

-26%Since 1971TrendPercent 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 →
8Routes 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 →
24YearsYears 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 Kentucky Warbler in Lower Great Lakes / St. Lawrence Plain. See the full index history below.

Kentucky Warbler In Lower Great Lakes / St. Lawrence Plain Population Forecast

If the recent trend holds, Kentucky Warbler in Lower Great Lakes / St. Lawrence Plain is projected to stay roughly flat through 2027, near 0.03 (95% range 0.00–0.05). A 5-year backtest shows a typical error of ±50.8%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2027TrendPercent 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 →
0.03Projected 2027 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.0595% 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 →
±50.8%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, Kentucky Warbler in Lower Great Lakes / St. Lawrence Plain is projected to stay roughly flat through 2027, near 0.03 (95% range 0.00–0.05). A 5-year backtest shows a typical error of ±50.8%, with 100% of held-out values landing inside the 95% band.19662027
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 →
20230.030.000.05
20240.030.000.05
20250.030.000.05
20260.030.000.05
20270.030.000.05

Routes In Lower Great Lakes / St. Lawrence Plain

Routes recording Kentucky Warbler in Lower Great Lakes / St. Lawrence Plain.
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 →
MiddlefieldOHIO11970
LattasburgOHIO11984
HebronOHIO12013
Slippery RkPENNSYLVANIA11975
CloverPENNSYLVANIA12019
Ferris CrnrsPENNSYLVANIA11971
TeeplevillePENNSYLVANIA12010
HarrisvillePENNSYLVANIA12022

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