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

Anna's Hummingbird In Coastal California

All regionsCoastal CaliforniaGeneralists

Anna's Hummingbird in Coastal California has surged: up 175% on the route-weighted index since 1970.

+175%Since 1970TrendPercent 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 →
116Routes 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 →
56YearsYears 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 →

Anna's Hummingbird has surged in Coastal California: up 175% on the route-weighted index since 1970.

Anna's Hummingbird In Coastal California Population Forecast

If the recent trend holds, Anna's Hummingbird in Coastal California is projected to stay roughly flat through 2029, near 4.5 (95% range 3.5–5.6). A 5-year backtest shows a typical error of ±22.9%, with 60% of held-out values landing inside the 95% band.

+6%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 →
4.5Projected 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 →
3.5–5.695% 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 →
±22.9%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, Anna's Hummingbird in Coastal California is projected to stay roughly flat through 2029, near 4.5 (95% range 3.5–5.6). A 5-year backtest shows a typical error of ±22.9%, with 60% of held-out values landing inside the 95% band.19682029
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 →
20254.43.35.4
20264.43.35.5
20274.53.45.5
20284.53.45.6
20294.53.55.6

Routes In Coastal California

Routes recording Anna's Hummingbird 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 →
Elsinore MtnCALIFORNIA392024
MorenoCALIFORNIA192024
Lake CachumaCALIFORNIA172016
FairfaxCALIFORNIA162024
San YsidroCALIFORNIA142019
Green ValleyCALIFORNIA142023
Tres PinosCALIFORNIA112003
PowayCALIFORNIA111980
CoyoteCALIFORNIA112024
Waterman GapCALIFORNIA112024
Tres Pinos 2CALIFORNIA112011
ColmaCALIFORNIA101972
RumseyCALIFORNIA92008
Morro BayCALIFORNIA92019
Lake Hemet 2CALIFORNIA92023
FolsomCALIFORNIA82024
Mt LagunaCALIFORNIA81987
Mt BaldyCALIFORNIA82024
ArvinCALIFORNIA82019
Orange CoveCALIFORNIA72016
SisquocCALIFORNIA72014
AdelaidaCALIFORNIA72024
White RiverCALIFORNIA71992
Mark WestCALIFORNIA72024
Glen EllenCALIFORNIA72004

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