BirdAnalyst
Species · BCR 13 · BBS 2026 Release · 1966–2025

Swamp Sparrow In Lower Great Lakes / St. Lawrence Plain

All regionsLower Great Lakes / St. Lawrence PlainWetland birds

Swamp Sparrow in Lower Great Lakes / St. Lawrence Plain has surged: up 98% on the route-weighted index since 1968.

+98%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 →
81Routes 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 →

Swamp Sparrow has surged in Lower Great Lakes / St. Lawrence Plain: up 98% on the route-weighted index since 1968.

Swamp Sparrow In Lower Great Lakes / St. Lawrence Plain Population Forecast

If the recent trend holds, Swamp Sparrow in Lower Great Lakes / St. Lawrence Plain is projected to fall about 28% by 2030 — from 2.4 in 2025 to a central estimate of 1.7 (95% range 1.0–2.5). A 5-year backtest shows a typical error of ±30.8%, with 20% of held-out values landing inside the 95% band.

-28%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 →
1.7Projected 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 →
1.0–2.595% 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 →
±30.8%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, Swamp Sparrow in Lower Great Lakes / St. Lawrence Plain is projected to fall about 28% by 2030 — from 2.4 in 2025 to a central estimate of 1.7 (95% range 1.0–2.5). A 5-year backtest shows a typical error of ±30.8%, with 20% 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 →
20261.70.962.4
20271.70.972.4
20281.70.982.4
20291.71.002.4
20301.71.02.5

Routes In Lower Great Lakes / St. Lawrence Plain

Routes recording Swamp Sparrow 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 →
HinesburgVERMONT141994
Ferris CrnrsPENNSYLVANIA102025
North EastonNEW-YORK92025
Oriskany FlsNEW-YORK82025
NashvilleNEW-YORK72018
PhiladelphiaNEW-YORK72025
ChurchvilleNEW-YORK62025
OgdensburgNEW-YORK62025
CrescentNEW-YORK62024
BristolVERMONT62025
DuanesburgNEW-YORK52025
RandolphNEW-YORK52018
ByronNEW-YORK52025
N WilmurtNEW-YORK51998
NaplesNEW-YORK52025
BalmatNEW-YORK52008
GarrettsvileOHIO51991
TeeplevillePENNSYLVANIA52025
TrumansburgNEW-YORK42024
CastileNEW-YORK42025
WatertownNEW-YORK42012
Sugar GrovePENNSYLVANIA42025
North PownalVERMONT42025
RhinebeckNEW-YORK32018
Ballston LkNEW-YORK31970

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