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

Vesper Sparrow In Lower Great Lakes / St. Lawrence Plain

All regionsLower Great Lakes / St. Lawrence PlainGrassland birds

Vesper Sparrow in Lower Great Lakes / St. Lawrence Plain has collapsed: down 86% on the route-weighted index since 1968.

-86%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 →
78Routes 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 →
58YearsYears 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 declinecomputed 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 →

Vesper Sparrow has collapsed in Lower Great Lakes / St. Lawrence Plain: down 86% on the route-weighted index since 1968.

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

If the recent trend holds, Vesper Sparrow in Lower Great Lakes / St. Lawrence Plain is projected to stay roughly flat through 2029, near 0.42 (95% range 0.00–1.6). A 5-year backtest shows a typical error of ±25.1%, with 100% of held-out values landing inside the 95% band.

-9%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 →
0.42Projected 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 →
0.00–1.695% 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 →
±25.1%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, Vesper Sparrow in Lower Great Lakes / St. Lawrence Plain is projected to stay roughly flat through 2029, near 0.42 (95% range 0.00–1.6). A 5-year backtest shows a typical error of ±25.1%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20250.530.001.8
20260.500.001.7
20270.470.001.7
20280.450.001.7
20290.420.001.6

Routes In Lower Great Lakes / St. Lawrence Plain

Routes recording Vesper 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 →
OrleansNEW-YORK102024
ByronNEW-YORK72024
Ballston LkNEW-YORK41969
ShaftsburyVERMONT41967
Grand IsleVERMONT41987
MacdougallNEW-YORK32023
West BangorNEW-YORK31990
PeruOHIO31978
AkeleyPENNSYLVANIA31970
AusterlitzNEW-YORK22008
CayugaNEW-YORK21996
TrumansburgNEW-YORK22002
RushvilleNEW-YORK22024
BranchportNEW-YORK22000
CastileNEW-YORK22019
RandolphNEW-YORK22002
ChurchvilleNEW-YORK22023
PenfieldNEW-YORK21976
N Victory 2NEW-YORK22004
Cicero CtrNEW-YORK21987
BalmatNEW-YORK21991
GarrettsvileOHIO21990
StrongsvilleOHIO21979
Herner CrnsOHIO21988
New SomersetOHIO21979

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