BirdAnalyst
Species · BCR 22 · BBS 2025 Release · 1966–2024

Grasshopper Sparrow In Eastern Tallgrass Prairie

All regionsEastern Tallgrass PrairieGrassland birds

Grasshopper Sparrow in Eastern Tallgrass Prairie has collapsed: down 83% on the route-weighted index since 1968.

-83%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 →
260Routes 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 →

Grasshopper Sparrow has collapsed in Eastern Tallgrass Prairie: down 83% on the route-weighted index since 1968.

Forecast

If the recent trend holds, Grasshopper Sparrow in Eastern Tallgrass Prairie is projected to rise about 14% by 2029 — from 1.2 in 2024 to a central estimate of 1.4 (95% range 0.00–3.4). A 5-year backtest shows a typical error of ±84%, with 100% of held-out values landing inside the 95% band.

+14%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 →
1.4Projected 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 →
0.00–3.495% 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 →
±84%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 rise about 14% by 2029 — from 1.2 in 2024 to a central estimate of 1.4 (95% range 0.00–3.4). A 5-year backtest shows a typical error of ±84%, 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 →
20251.80.003.8
20261.70.003.7
20271.60.003.6
20281.50.003.5
20291.40.003.4

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 SandsINDIANA172024
BedfordIOWA152018
LaplandKANSAS152022
WrefordKANSAS152024
HamiltonMISSOURI141985
New HamptonMISSOURI132024
LucerneMISSOURI132021
NewportOHIO121994
BolckowMISSOURI91992
EmdenMISSOURI92024
ClaytonILLINOIS82019
GaryINDIANA81984
ForakerOKLAHOMA82024
Duncan MillsILLINOIS72024
College SpgsIOWA72004
KahokaMISSOURI71998
KirksvilleMISSOURI72024
MelroseKANSAS62018
BarclayKANSAS62024
LacledeMISSOURI62024
LurayMISSOURI62024
HumboldtNEBRASKA62024
GreenviewILLINOIS52024

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