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

Swainson's Thrush In Lower Great Lakes / St. Lawrence Plain

All regionsLower Great Lakes / St. Lawrence PlainForest birds

Swainson's Thrush in Lower Great Lakes / St. Lawrence Plain has declined: down 38% on the route-weighted index since 1971.

-38%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 →
6Routes 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 →
34YearsYears 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 Swainson's Thrush in Lower Great Lakes / St. Lawrence Plain. See the full index history below.

Forecast

If the recent trend holds, Swainson's Thrush in Lower Great Lakes / St. Lawrence Plain is projected to stay roughly flat through 2017, near 0.04 (95% range 0.00–0.16). A 5-year backtest shows a typical error of ±143.2%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2017TrendPercent 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 →
0.04Projected 2017 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.1695% 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 →
±143.2%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, Swainson's Thrush in Lower Great Lakes / St. Lawrence Plain is projected to stay roughly flat through 2017, near 0.04 (95% range 0.00–0.16). A 5-year backtest shows a typical error of ±143.2%, with 100% of held-out values landing inside the 95% band.19682017
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 →
20130.040.000.16
20140.040.000.16
20150.040.000.16
20160.040.000.16
20170.040.000.16

Routes In Lower Great Lakes / St. Lawrence Plain

Routes recording Swainson's Thrush 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 →
BalmatNEW-YORK31991
W ShokanNEW-YORK12012
RandolphNEW-YORK12012
Alder CreekNEW-YORK11984
N WilmurtNEW-YORK11997
HinesburgVERMONT11983

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