BirdAnalyst
Species · Arizona · BBS 2026 Release · 1966–2025

Cliff Swallow Population Trend in Arizona

All statesAerial insectivores

Cliff Swallow in Arizona has fallen sharply: down 56% on the route-weighted index since 1970.

-56%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 →
52Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Cliff Swallow 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 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 →

Cliff Swallow has fallen sharply in Arizona: down 56% on the route-weighted index since 1970.

Cliff Swallow Population Forecast in Arizona

If the recent trend holds, Cliff Swallow in Arizona is projected to rise about 199% by 2030 — from 3.0 in 2025 to a central estimate of 8.8 (95% range 0.00–19). A 5-year backtest shows a typical error of ±160%, with 100% of held-out values landing inside the 95% band.

+199%Change by 2030TrendPercent 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 →
8.8Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–1995% 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 →
±160%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, Cliff Swallow in Arizona is projected to rise about 199% by 2030 — from 3.0 in 2025 to a central estimate of 8.8 (95% range 0.00–19). A 5-year backtest shows a typical error of ±160%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20268.80.0019
20278.80.0019
20288.80.0019
20298.80.0019
20308.80.0019

Cliff Swallow Survey Routes in Arizona

Routes recording Cliff Swallow 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 →
Sunizona 210020172014
Dateland6620241991
Cactus Forest5420251991
Laguna4220231968
Casa Grande3620231989
Cutter 23320182015
Florence3019761968
Vicksburg2419891989
Skull Valley 22220252025
Cibola Lake1520241993
Mormon Lake1419711971
New River1320161991
Blue1019891974
Coolidge1019851974
Palo Verde 21020252014
Williams1020252025
Carr Mtn1020251986
Pomerene820251968
Hope 2820192014
Seligman720171991
Skull Valley620241996
Amado620182009
The Gap419731969
Palo Verde420131992
Araby420231992

Cliff Swallow Population Trend in Other States

alabamaalaskaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.