BirdAnalyst
Species · BCR 5 · BBS 2025 Release · 1966–2024

Grasshopper Sparrow In Northern Pacific Rainforest

All regionsNorthern Pacific RainforestGrassland birds

Grasshopper Sparrow in Northern Pacific Rainforest has fallen sharply: down 65% on the route-weighted index since 1974.

-65%Since 1974TrendPercent 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 →
23Routes 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 →
49YearsYears 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 Northern Pacific Rainforest: down 65% on the route-weighted index since 1974.

Forecast

If the recent trend holds, Grasshopper Sparrow in Northern Pacific Rainforest is projected to stay roughly flat through 2029, near 0.15 (95% range 0.00–0.38). A 5-year backtest shows a typical error of ±638%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.15Projected 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 →
0.00–0.3895% 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 →
±638%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 Northern Pacific Rainforest is projected to stay roughly flat through 2029, near 0.15 (95% range 0.00–0.38). A 5-year backtest shows a typical error of ±638%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20250.150.000.38
20260.150.000.38
20270.150.000.38
20280.150.000.38
20290.150.000.38

Routes In Northern Pacific Rainforest

Routes recording Grasshopper Sparrow in Northern Pacific Rainforest.
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 →
AlderpointCALIFORNIA162012
Mt ShastaCALIFORNIA71976
Rio DellCALIFORNIA52007
UmpquaOREGON42021
KamilcheWASHINGTON41971
HolmesCALIFORNIA32008
Martins FyCALIFORNIA32008
LaytonvilleCALIFORNIA32012
GarfieldOREGON31979
HoneydewCALIFORNIA22017
IlwacoWASHINGTON21997
Fish RockCALIFORNIA12001
NavarroCALIFORNIA12000
LongvaleCALIFORNIA12016
Bodega BayCALIFORNIA12018
YrekaCALIFORNIA12018
KorbelCALIFORNIA12015
Friday RidgeCALIFORNIA12009
AdairOREGON12024
ElktonOREGON12010
Sams ValleyOREGON12021
SalemOREGON12015
ProspectOREGON11995

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