BirdAnalyst
Species · BCR 22 · BBS 2026 Release · 1966–2025

Grasshopper Sparrow In Eastern Tallgrass Prairie

All regionsEastern Tallgrass PrairieGrassland birds

Grasshopper Sparrow in Eastern Tallgrass Prairie has collapsed: down 84% on the route-weighted index since 1968.

-84%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 →
261Routes 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 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 →

Grasshopper Sparrow has collapsed in Eastern Tallgrass Prairie: down 84% on the route-weighted index since 1968.

Grasshopper Sparrow In Eastern Tallgrass Prairie Population Forecast

If the recent trend holds, Grasshopper Sparrow in Eastern Tallgrass Prairie is projected to stay roughly flat through 2030, near 1.3 (95% range 0.00–3.2). A 5-year backtest shows a typical error of ±87.4%, with 100% of held-out values landing inside the 95% band.

+6%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 →
1.3Projected 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 →
0.00–3.295% 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 →
±87.4%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, Grasshopper Sparrow in Eastern Tallgrass Prairie is projected to stay roughly flat through 2030, near 1.3 (95% range 0.00–3.2). A 5-year backtest shows a typical error of ±87.4%, with 100% 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 →
20261.70.003.6
20271.60.003.5
20281.50.003.4
20291.40.003.3
20301.30.003.2

Routes In Eastern Tallgrass Prairie

Routes recording Grasshopper Sparrow in Eastern Tallgrass Prairie.
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 →
ThrallKANSAS331970
LincolnvilleKANSAS242024
Kankakee SandsINDIANA212025
New HamptonMISSOURI202025
LucerneMISSOURI162025
LaplandKANSAS152022
WrefordKANSAS152024
HamiltonMISSOURI141985
LurayMISSOURI122025
NewportOHIO121994
KirksvilleMISSOURI112025
McfallMISSOURI112025
SticklervillMISSOURI102025
BolckowMISSOURI91992
EmdenMISSOURI92024
JohnsonNEBRASKA92025
GaryINDIANA81984
College SpgsIOWA72004
KahokaMISSOURI71998
ForakerOKLAHOMA72025
BedfordIOWA62025
MelroseKANSAS62018
LacledeMISSOURI62024
Bluff SpgsILLINOIS52025
BarclayKANSAS52025

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