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Species · Idaho · BBS 2025 Release · 1966–2024

White-faced Ibis Population Trend in Idaho

All statesWetland birds

White-faced Ibis in Idaho has surged: up 198% on the route-weighted index since 1973.

+198%Since 1973TrendPercent 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 StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
46YearsYears 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 IdahoNotable 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 →

White-faced Ibis has surged in Idaho: up 198% on the route-weighted index since 1973.

White-faced Ibis Population Forecast in Idaho

If the recent trend holds, White-faced Ibis in Idaho is projected to rise about 63× by 2029 — from 0.16 in 2024 to a central estimate of 10 (95% range 0.00–23). A 5-year backtest shows a typical error of ±1681.9%, with 100% of held-out values landing inside the 95% band.

63×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 →
10Projected 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 →
0.00–2395% 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 →
±1681.9%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, White-faced Ibis in Idaho is projected to rise about 63× by 2029 — from 0.16 in 2024 to a central estimate of 10 (95% range 0.00–23). A 5-year backtest shows a typical error of ±1681.9%, with 100% of held-out values landing inside the 95% band.19712029
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 →
20259.60.0022
20269.80.0022
20279.90.0023
2028100.0023
2029100.0023

White-faced Ibis Survey Routes in Idaho

Routes recording White-faced Ibis in Idaho.
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 →
Preston3720231988
Cedar Hill2920222002
Pocatello2520191981
Springfield1220141971
Blackft Res720012001
Picabo720212021
Mud Lake520231988
Tractor Flat420241991
Ririe320221987
Iron Springs120152015

White-faced Ibis Population Trend in Other States

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