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Species · Colorado · BBS 2025 Release · 1966–2024

White-faced Ibis Population Trend in Colorado

All statesWetland birds

White-faced Ibis in Colorado has collapsed: down 94% on the route-weighted index since 1991.

-94%Since 1991TrendPercent 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 →
26Routes 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 →
34YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable White-faced Ibis 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 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 →

White-faced Ibis has collapsed in Colorado: down 94% on the route-weighted index since 1991.

White-faced Ibis Population Forecast in Colorado

If the recent trend holds, White-faced Ibis in Colorado is projected to stay roughly flat through 2029, near 0.03 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±249.1%, 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 →
0.03Projected 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 →
0.00–1.195% 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 →
±249.1%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, White-faced Ibis in Colorado is projected to stay roughly flat through 2029, near 0.03 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±249.1%, with 100% of held-out values landing inside the 95% band.19882029
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 →
20250.120.001.2
20260.100.001.2
20270.070.001.2
20280.050.001.1
20290.030.001.1

White-faced Ibis Survey Routes in Colorado

Routes recording White-faced Ibis 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 →
Fruita4120062001
San Luis1320212021
Moffat1219991991
Doyle Bridge 21219991999
Mcphee Res.1020162012
Kiowa920002000
Hudson820122006
Dinosaur820102010
Doyleville820181989
Angora820102009
Mosca719941994
Fort Morgan520012001
Julesburg520212008
Cortez520031989
Cortez 2420132013
Guffey320182001
Weston Pass320002000
Alamosa320241988
Flagler320122012
Neegrande320182018
Tarryall220082008
Lay220012001
Arsenal 2120222022
Edison120232023
Tincup120181996

White-faced Ibis Population Trend in Other States

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