BirdAnalyst
Species · BCR 12 · BBS 2025 Release · 1966–2024

Grasshopper Sparrow In Boreal Hardwood Transition

All regionsBoreal Hardwood TransitionGrassland birds

Grasshopper Sparrow in Boreal Hardwood Transition has fallen sharply: down 56% on the route-weighted index since 1968.

-56%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 →
76Routes 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 fallen sharply in Boreal Hardwood Transition: down 55% on the route-weighted index since 1968.

Forecast

If the recent trend holds, Grasshopper Sparrow in Boreal Hardwood Transition is projected to rise about 76% by 2029 — from 0.16 in 2024 to a central estimate of 0.28 (95% range 0.00–0.71). A 5-year backtest shows a typical error of ±49.1%, with 100% of held-out values landing inside the 95% band.

+76%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 →
0.28Projected 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 →
0.00–0.7195% 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 →
±49.1%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, Grasshopper Sparrow in Boreal Hardwood Transition is projected to rise about 76% by 2029 — from 0.16 in 2024 to a central estimate of 0.28 (95% range 0.00–0.71). A 5-year backtest shows a typical error of ±49.1%, 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 →
20250.310.000.74
20260.300.000.73
20270.290.000.73
20280.290.000.72
20290.280.000.71

Routes In Boreal Hardwood Transition

Routes recording Grasshopper Sparrow in Boreal Hardwood Transition.
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 →
WarroadMINNESOTA151993
CathroMICHIGAN82015
BrainerdMINNESOTA82002
OntonagonMICHIGAN62019
Skegemog PtMICHIGAN62024
Pine RiverMINNESOTA62018
RacoMICHIGAN51993
Walloon LakeMICHIGAN52004
MayfieldMICHIGAN52022
BackusMINNESOTA42022
GreenbushMINNESOTA42024
Nett LakeMINNESOTA42013
BigforkMINNESOTA31998
PhillipsWISCONSIN32007
RhinelanderWISCONSIN32009
IsabellaMICHIGAN22008
TahquamenonMICHIGAN22014
Traverse CtyMICHIGAN21992
Beaver LakeMICHIGAN21994
CohassetMINNESOTA21973
BemidjiMINNESOTA21979
Iron RiverWISCONSIN22023
CouderayWISCONSIN21997
IrmaWISCONSIN21970
BerglandMICHIGAN11990

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