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

Henslow's Sparrow In Lower Great Lakes / St. Lawrence Plain

All regionsLower Great Lakes / St. Lawrence PlainGrassland birds

Henslow's Sparrow in Lower Great Lakes / St. Lawrence Plain has collapsed: down 95% on the route-weighted index since 1968.

-95%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 →
42Routes 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 →

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 →

Henslow's Sparrow has collapsed in Lower Great Lakes / St. Lawrence Plain: down 94% on the route-weighted index since 1968.

Forecast

If the recent trend holds, Henslow's Sparrow in Lower Great Lakes / St. Lawrence Plain is projected to stay roughly flat through 2007, near 0.00 (95% range 0.00–0.24). A 5-year backtest shows a typical error of ±701.3%, with 80% of held-out values landing inside the 95% band.

n/aChange by 2007TrendPercent 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 →
0.00Projected 2007 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.2495% 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 →
±701.3%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, Henslow's Sparrow in Lower Great Lakes / St. Lawrence Plain is projected to stay roughly flat through 2007, near 0.00 (95% range 0.00–0.24). A 5-year backtest shows a typical error of ±701.3%, with 80% of held-out values landing inside the 95% band.19662007
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 →
20030.000.000.24
20040.000.000.24
20050.000.000.24
20060.000.000.24
20070.000.000.24

Routes In Lower Great Lakes / St. Lawrence Plain

Routes recording Henslow's 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 →
WatertownNEW-YORK51973
OneidaNEW-YORK41976
CloverPENNSYLVANIA41993
TrumansburgNEW-YORK21994
BranchportNEW-YORK21997
SheridanNEW-YORK21989
PulaskiNEW-YORK21991
StrongsvilleOHIO21973
HebronOHIO21996
HarmonsburgPENNSYLVANIA21984
AkeleyPENNSYLVANIA21972
Sugar GrovePENNSYLVANIA21984
Oriskany FlsNEW-YORK11977
RomulusNEW-YORK11993
MacdougallNEW-YORK11989
OrleansNEW-YORK11997
RushvilleNEW-YORK11970
Canadice LNEW-YORK11979
MendonNEW-YORK11984
Mt MorrisNEW-YORK12002
HamburgNEW-YORK11970
West SenecaNEW-YORK11984
RandolphNEW-YORK11967
Cherry HillNEW-YORK11985
NashvilleNEW-YORK11987

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