BirdAnalyst
Species · BCR 29 · BBS 2026 Release · 1966–2025

Grasshopper Sparrow In Piedmont

All regionsPiedmontGrassland birds

Grasshopper Sparrow in Piedmont has collapsed: down 80% on the route-weighted index since 1968.

-80%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 →
144Routes 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 Piedmont: down 80% on the route-weighted index since 1968.

Grasshopper Sparrow In Piedmont Population Forecast

If the recent trend holds, Grasshopper Sparrow in Piedmont is projected to fall about 51% by 2030 — from 1.3 in 2025 to a central estimate of 0.63 (95% range 0.00–2.3). A 5-year backtest shows a typical error of ±47.3%, with 100% of held-out values landing inside the 95% band.

-51%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 →
0.63Projected 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 →
0.00–2.395% 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 →
±47.3%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, Grasshopper Sparrow in Piedmont is projected to fall about 51% by 2030 — from 1.3 in 2025 to a central estimate of 0.63 (95% range 0.00–2.3). A 5-year backtest shows a typical error of ±47.3%, 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 →
20260.900.002.6
20270.830.002.5
20280.760.002.5
20290.690.002.4
20300.630.002.3

Routes In Piedmont

Routes recording Grasshopper Sparrow in Piedmont.
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 →
CherryvilleNORTH-CAROLINA161968
PendletonSOUTH-CAROLINA151976
EmmitsburgMARYLAND132025
MonticelloNORTH-CAROLINA102025
WylliesburgVIRGINIA102019
MadonnaMARYLAND92022
TaylorstownVIRGINIA82010
RinggoldVIRGINIA82025
IjamsvilleMARYLAND72025
FlayNORTH-CAROLINA72025
WarfieldsbrgMARYLAND62025
OwingsSOUTH-CAROLINA62004
LincolntonGEORGIA51995
Rock BranchGEORGIA52025
Stoney Point 2GEORGIA52019
OlneyMARYLAND52025
CrotonNEW-JERSEY52007
LabottPENNSYLVANIA51983
ShrewsburyPENNSYLVANIA52023
PartlowVIRGINIA52007
MetasvilleGEORGIA42000
EkloMARYLAND42018
WheatonMARYLAND41995
MadisonNORTH-CAROLINA41985
EdenNORTH-CAROLINA42024

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