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

Cliff Swallow Population Trend in Alabama

All statesAerial insectivores

Cliff Swallow in Alabama has surged: up 173× on the route-weighted index since 1971.

173×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 →
66Routes 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 →
54YearsYears 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 AlabamaNotable 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 →

Cliff Swallow has surged in Alabama: up 173× on the route-weighted index since 1971.

Cliff Swallow Population Forecast in Alabama

If the recent trend holds, Cliff Swallow in Alabama is projected to fall about 39% by 2029 — from 30 in 2024 to a central estimate of 18 (95% range 11–26). A 5-year backtest shows a typical error of ±23.3%, with 80% of held-out values landing inside the 95% band.

-39%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 →
18Projected 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 →
11–2695% 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 →
±23.3%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 Alabama is projected to fall about 39% by 2029 — from 30 in 2024 to a central estimate of 18 (95% range 11–26). A 5-year backtest shows a typical error of ±23.3%, with 80% 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 →
2025179.324
2026179.625
20271810.025
2028181025
2029181126

Cliff Swallow Survey Routes in Alabama

Routes recording Cliff Swallow in Alabama.
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 →
Pine Grove70020241977
Epes50720241987
Triana41720122000
Sprott-Cahaba Riv30020141999
Riverside22720132000
Swaim18220241980
Guntersville10620171980
Mt Olive7020241996
Smyer Lake5720222009
Stevenson5220241996
Billingsley4020222000
Oneonta3020232005
Gastonburg3020222018
Seale3020172008
Vina2720231997
Talladega2720242003
Elkmont2320241994
Wheeler Dam2220231995
Valhermoso Spgs2020101978
Holt2020242003
Hillsboro1919931993
Wedgeworth1920241998
Childersburg1819991998
St. Elmo1820212001
Liberty1620222008

Cliff Swallow Population Trend in Other States

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

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