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

Northern Rough-winged Swallow Population Trend in Arizona

All statesAerial insectivores

Northern Rough-winged 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 →
58Routes 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 →
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 Northern Rough-winged 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 →

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

Northern Rough-winged Swallow Population Forecast in Arizona

If the recent trend holds, Northern Rough-winged Swallow in Arizona is projected to rise about 68% by 2029 — from 0.71 in 2024 to a central estimate of 1.2 (95% range 0.00–9.6). A 5-year backtest shows a typical error of ±97.7%, with 100% of held-out values landing inside the 95% band.

+68%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 →
1.2Projected 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 →
0.00–9.695% 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 →
±97.7%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, Northern Rough-winged Swallow in Arizona is projected to rise about 68% by 2029 — from 0.71 in 2024 to a central estimate of 1.2 (95% range 0.00–9.6). A 5-year backtest shows a typical error of ±97.7%, 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 →
20251.50.009.9
20261.40.009.8
20271.30.009.8
20281.30.009.7
20291.20.009.6

Northern Rough-winged Swallow Survey Routes in Arizona

Routes recording Northern Rough-winged 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 →
Cutter16820141993
Cutter 211120182015
Palo Verde2020131992
Palo Verde 21920242014
Cactus Forest1520211993
Mcneal1420172014
Red Rock1020142010
Rose Wells819691968
Laguna820231968
Tonto Vill.520172016
Organ Pipe420182018
Hunt419951976
San Simon419951995
Greasewood419931993
Round Rock319721972
Oatman320161995
New River320152014
Florence319881968
Peña Blanca320001975
Seligman320161999
Hope320041996
Mormon Lake219741974
Zeniff219841984
Blue219911976
Ajo220062000

Northern Rough-winged 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.