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

Common Loon In Lower Great Lakes / St. Lawrence Plain

All regionsLower Great Lakes / St. Lawrence PlainWetland birds

Common Loon in Lower Great Lakes / St. Lawrence Plain has increased: up 38% on the route-weighted index since 1983.

+38%Since 1983TrendPercent 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 →
7Routes 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 →
21YearsYears 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 Common Loon in Lower Great Lakes / St. Lawrence Plain. See the full index history below.

Common Loon In Lower Great Lakes / St. Lawrence Plain Population Forecast

If the recent trend holds, Common Loon in Lower Great Lakes / St. Lawrence Plain is projected to fall about 40% by 2029 — from 0.06 in 2024 to a central estimate of 0.04 (95% range 0.01–0.07). A 5-year backtest shows a typical error of ±52.3%, with 100% of held-out values landing inside the 95% band.

-40%Change by 2029TrendPercent 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 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.01–0.0795% 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 →
±52.3%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, Common Loon in Lower Great Lakes / St. Lawrence Plain is projected to fall about 40% by 2029 — from 0.06 in 2024 to a central estimate of 0.04 (95% range 0.01–0.07). A 5-year backtest shows a typical error of ±52.3%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20250.040.010.06
20260.040.010.06
20270.040.010.06
20280.040.010.06
20290.040.010.07

Routes In Lower Great Lakes / St. Lawrence Plain

Routes recording Common Loon 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 →
MacdougallNEW-YORK11999
PulaskiNEW-YORK12023
OgdensburgNEW-YORK11989
ParishvilleNEW-YORK12024
WillsboroNEW-YORK12019
PhiladelphiaNEW-YORK12024
Grand IsleVERMONT12024

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