BirdAnalyst
Species · BCR 35 · BBS 2025 Release · 1966–2024

Grasshopper Sparrow In Chihuahuan Desert

All regionsChihuahuan DesertGrassland birds

Grasshopper Sparrow in Chihuahuan Desert has declined: down 37% on the route-weighted index since 1982.

-37%Since 1982TrendPercent 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 →
10Routes 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 →
32YearsYears 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 →

No notable trend signals for Grasshopper Sparrow in Chihuahuan Desert. See the full index history below.

Forecast

If the recent trend holds, Grasshopper Sparrow in Chihuahuan Desert is projected to fall about 66% by 2028 — from 0.15 in 2023 to a central estimate of 0.05 (95% range 0.00–0.29). A 5-year backtest shows a typical error of ±49.9%, with 100% of held-out values landing inside the 95% band.

-66%Change by 2028TrendPercent 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 →
0.05Projected 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.2995% 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 →
±49.9%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 Chihuahuan Desert is projected to fall about 66% by 2028 — from 0.15 in 2023 to a central estimate of 0.05 (95% range 0.00–0.29). A 5-year backtest shows a typical error of ±49.9%, with 100% of held-out values landing inside the 95% band.19772028
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 →
20240.070.000.31
20250.070.000.30
20260.060.000.30
20270.060.000.29
20280.050.000.29

Routes In Chihuahuan Desert

Routes recording Grasshopper Sparrow in Chihuahuan Desert.
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 →
Bitter LakeNEW-MEXICO21997
Lake ValleyNEW-MEXICO22007
MarfaTEXAS22023
RoswellNEW-MEXICO12023
Hatchet PeakNEW-MEXICO12023
OzonaTEXAS12019
Casa PiedraTEXAS11992
Devils R CynTEXAS12009
MarathonTEXAS12019
Ft. DavisTEXAS12023

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