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

Barn Swallow Population Trend in Arizona

All statesAerial insectivores

Barn Swallow in Arizona has surged: up 233% on the route-weighted index since 1971.

+233%Since 1971TrendPercent 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 →
60Routes 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 →
55YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Barn 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 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 →

Barn Swallow has surged in Arizona: up 232% on the route-weighted index since 1971.

Barn Swallow Population Forecast in Arizona

If the recent trend holds, Barn Swallow in Arizona is projected to rise about 27% by 2029 — from 1.1 in 2024 to a central estimate of 1.4 (95% range 0.03–2.9). A 5-year backtest shows a typical error of ±33.1%, with 100% of held-out values landing inside the 95% band.

+27%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 →
1.4Projected 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 →
0.03–2.995% 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 →
±33.1%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, Barn Swallow in Arizona is projected to rise about 27% by 2029 — from 1.1 in 2024 to a central estimate of 1.4 (95% range 0.03–2.9). A 5-year backtest shows a typical error of ±33.1%, 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 →
20251.40.002.8
20261.40.002.8
20271.40.012.8
20281.40.022.9
20291.40.032.9

Barn Swallow Survey Routes in Arizona

Routes recording Barn 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 →
Flagstaff1220161994
Pinetop1020221993
Peach Spring1020241999
Ajo 2820132013
Clay Spring720241999
Sunizona619971971
Skull Valley620242014
Hunt520181968
Dateland420211990
Castle Butte420061995
Mt. Graham419961996
Sunizona 2420232001
Laguna320231975
Pomerene320241982
Patagonia320241971
Cutter 2320172015
Antares320182004
Williams320191999
Maine320241992
Palo Verde320131992
Redington320221993
Sahuarita320242011
Hope320092003
Sprucedale320192017
Prescott220161998

Barn Swallow Population Trend in Other States

alabamaalaskaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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