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Species · Colorado · BBS 2025 Release · 1966–2024

Gambel's Quail Population Trend in Colorado

All statesArid-land birds

Gambel's Quail in Colorado has surged: up 135% on the route-weighted index since 1992.

+135%Since 1992TrendPercent 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 →
9Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
23YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Gambel's Quail Trends in ColoradoNotable 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 increasecomputed 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 →

Gambel's Quail has surged in Colorado: up 135% on the route-weighted index since 1992.

Gambel's Quail Population Forecast in Colorado

If the recent trend holds, Gambel's Quail in Colorado is projected to rise about 44% by 2029 — from 0.08 in 2024 to a central estimate of 0.12 (95% range 0.01–0.22). A 5-year backtest shows a typical error of ±78.4%, with 100% of held-out values landing inside the 95% band.

+44%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 →
0.12Projected 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 →
0.01–0.2295% 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 →
±78.4%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, Gambel's Quail in Colorado is projected to rise about 44% by 2029 — from 0.08 in 2024 to a central estimate of 0.12 (95% range 0.01–0.22). A 5-year backtest shows a typical error of ±78.4%, with 100% of held-out values landing inside the 95% band.19812029
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 →
20250.110.010.21
20260.110.010.22
20270.110.010.22
20280.120.010.22
20290.120.010.22

Gambel's Quail Survey Routes in Colorado

Routes recording Gambel's Quail in Colorado.
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 →
Fruita820031990
Rosevale420242009
Willow Peak219921992
Douglas Pass220242022
Animas 2220152012
Mesaverde Np120072007
Delta119811981
De Beque120242024
Baxter Pass120242024

Gambel's Quail Population Trend in Other States

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