BirdAnalyst
Species · BCR 32 · BBS 2025 Release · 1966–2024

White-faced Ibis In Coastal California

All regionsCoastal CaliforniaWetland birds

White-faced Ibis in Coastal California has surged: up 58× on the route-weighted index since 1986.

58×Since 1986TrendPercent 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 →
18Routes 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 →
37YearsYears 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 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 Coastal California: up 58× on the route-weighted index since 1986.

White-faced Ibis In Coastal California Population Forecast

If the recent trend holds, White-faced Ibis in Coastal California is projected to rise about 247% by 2029 — from 1.1 in 2024 to a central estimate of 3.8 (95% range 0.04–7.6). A 5-year backtest shows a typical error of ±275.2%, with 100% of held-out values landing inside the 95% band.

+247%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 →
3.8Projected 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 →
0.04–7.695% 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 →
±275.2%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 Coastal California is projected to rise about 247% by 2029 — from 1.1 in 2024 to a central estimate of 3.8 (95% range 0.04–7.6). A 5-year backtest shows a typical error of ±275.2%, with 100% of held-out values landing inside the 95% band.19722029
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 →
20253.50.007.3
20263.60.007.4
20273.70.007.5
20283.80.007.6
20293.80.047.6

Routes In Coastal California

Routes recording White-faced Ibis in Coastal California.
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 →
GlennCALIFORNIA2052021
ArvinCALIFORNIA1502022
AtwaterCALIFORNIA502012
OrlandCALIFORNIA352004
OrovilleCALIFORNIA352013
ZamoraCALIFORNIA302017
Ora LomaCALIFORNIA302024
Red BluffCALIFORNIA292014
Staten Is.CALIFORNIA222014
HughsonCALIFORNIA172024
WestleyCALIFORNIA142023
Buena VistaCALIFORNIA92019
PenningtonCALIFORNIA72014
MorenoCALIFORNIA52022
Jofegan 2CALIFORNIA52024
TranquillityCALIFORNIA22004
RiovistaCALIFORNIA11972
Anza 2CALIFORNIA12021

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