BirdAnalyst
Species · Arizona · BBS 2025 Release · 1966–2024

Costa's Hummingbird Population Trend in Arizona

All statesGeneralists

Costa's Hummingbird in Arizona has surged: up 200% on the route-weighted index since 1976.

+200%Since 1976TrendPercent 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 →
27Routes 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 →
40YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Costa's Hummingbird Trends in ArizonaNotable 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 →

Costa's Hummingbird has surged in Arizona: up 200% on the route-weighted index since 1976.

Costa's Hummingbird Population Forecast in Arizona

If the recent trend holds, Costa's Hummingbird in Arizona is projected to rise about 20% by 2029 — from 0.34 in 2024 to a central estimate of 0.41 (95% range 0.11–0.71). A 5-year backtest shows a typical error of ±23.2%, with 100% of held-out values landing inside the 95% band.

+20%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 →
0.41Projected 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 →
0.11–0.7195% 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 →
±23.2%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, Costa's Hummingbird in Arizona is projected to rise about 20% by 2029 — from 0.34 in 2024 to a central estimate of 0.41 (95% range 0.11–0.71). A 5-year backtest shows a typical error of ±23.2%, with 100% 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 →
20250.390.090.69
20260.400.100.69
20270.400.100.70
20280.410.110.70
20290.410.110.71

Costa's Hummingbird Survey Routes in Arizona

Routes recording Costa's Hummingbird in Arizona.
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 →
Bates Well1320231995
Willow Beach 2620192019
Organ Pipe420231991
Cibola Lake420151993
Cabeza Priet320241995
Wickenburg320232018
Navajo Trail320092009
Peña Blanca220241975
Patagonia220132013
Alamo Res.220231992
Bartlett Res220242001
Ajo 2220182010
Oatman120181993
Wikieup119981992
Quartzsite120241998
New River120142014
Ajo120001968
Pomerene120082008
Red Rock 2120242015
Riviera120241992
Gila Bend120241999
Redington120191996
Amado120172008
Sahuarita120242010
Willow Beach119951993

Costa's Hummingbird Population Trend in Other States

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