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

Chimney Swift Population Trend in Alabama

All statesAerial insectivores

Chimney Swift in Alabama has fallen sharply: down 70% on the route-weighted index since 1968.

-70%Since 1968TrendPercent 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 →
109Routes 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 →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Chimney Swift 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 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 →

Chimney Swift has fallen sharply in Alabama: down 70% on the route-weighted index since 1968.

Chimney Swift Population Forecast in Alabama

If the recent trend holds, Chimney Swift in Alabama is projected to fall about 42% by 2029 — from 5.8 in 2024 to a central estimate of 3.4 (95% range 0.00–7.9). A 5-year backtest shows a typical error of ±14.5%, with 100% of held-out values landing inside the 95% band.

-42%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 →
3.4Projected 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 →
0.00–7.995% 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 →
±14.5%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, Chimney Swift in Alabama is projected to fall about 42% by 2029 — from 5.8 in 2024 to a central estimate of 3.4 (95% range 0.00–7.9). A 5-year backtest shows a typical error of ±14.5%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20254.60.029.1
20264.30.008.8
20274.00.008.5
20283.70.008.2
20293.40.007.9

Chimney Swift Survey Routes in Alabama

Routes recording Chimney Swift 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 →
Birmingham14519951969
Dearmanville4519831966
Howard4520241966
Riderwood2620231966
Summitt2319811966
St Florian1920241967
Dawson1919981966
Stevenson1920241996
Greensport1420241966
Brantley1320241966
Alabama Pt1220031966
Foley1219841966
Rock Chapel1220241995
Millerville1120241966
Wedgeworth1120241979
Valhermoso Spgs1020101966
Wallsboro1020211966
Dauphin Is1019901966
Alabama Pt 21020172004
Hillsboro919961966
Warrior Std920241966
Castleberry920241966
Liberty City920111979
Swaim820241966
Newton820241966

Chimney Swift Population Trend in Other States

arkansascoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

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