BirdAnalyst
Species · BCR 28 · BBS 2025 Release · 1966–2024

Grasshopper Sparrow In Appalachian Mountains

All regionsAppalachian MountainsGrassland birds

Grasshopper Sparrow in Appalachian Mountains has collapsed: down 92% on the route-weighted index since 1968.

-92%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 →
284Routes 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 Appalachian Mountains: down 92% on the route-weighted index since 1968.

Forecast

If the recent trend holds, Grasshopper Sparrow in Appalachian Mountains is projected to fall about 100% by 2029 — from 0.31 in 2024 to a central estimate of 0.00 (95% range 0.00–0.80). A 5-year backtest shows a typical error of ±127.8%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–0.8095% 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 →
±127.8%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 Appalachian Mountains is projected to fall about 100% by 2029 — from 0.31 in 2024 to a central estimate of 0.00 (95% range 0.00–0.80). A 5-year backtest shows a typical error of ±127.8%, 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 →
20250.000.000.80
20260.000.000.80
20270.000.000.80
20280.000.000.80
20290.000.000.80

Routes In Appalachian Mountains

Routes recording Grasshopper Sparrow in Appalachian Mountains.
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 →
SmithsburgMARYLAND142014
WilliamsportMARYLAND82024
MartinsburgWEST-VIRGINIA72024
N WashingtonPENNSYLVANIA62024
WaterstreetPENNSYLVANIA62024
Sleepy CreekWEST-VIRGINIA61990
NeedmorePENNSYLVANIA51991
Schaefferstown 2PENNSYLVANIA52024
CoventryvileNEW-YORK42001
StonecreekOHIO42022
Warrens MillPENNSYLVANIA42019
StoneybreakPENNSYLVANIA42024
Allens BrdgeTENNESSEE42023
Natural BridVIRGINIA42024
IvanhoeVIRGINIA41968
HebronVIRGINIA42009
Rural RetrtVIRGINIA42018
WoodvilleALABAMA32008
LinwoodGEORGIA32018
MckeeKENTUCKY31978
FinzelMARYLAND32024
BloomsburyNEW-JERSEY31991
CooperstownNEW-YORK31973
OxfordNEW-YORK31967
AustinvillePENNSYLVANIA32019

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