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

Tree Swallow Population Trend in Alabama

All statesAerial insectivores

Tree Swallow in Alabama has surged: up 469% on the route-weighted index since 1996.

+469%Since 1996TrendPercent 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 →
37Routes 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 →
27YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Tree 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 →

Tree Swallow has surged in Alabama: up 469% on the route-weighted index since 1996.

Tree Swallow Population Forecast in Alabama

If the recent trend holds, Tree Swallow in Alabama is projected to fall about 20% by 2030 — from 0.53 in 2025 to a central estimate of 0.42 (95% range 0.13–0.72). A 5-year backtest shows a typical error of ±23.1%, with 100% of held-out values landing inside the 95% band.

-20%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 →
0.42Projected 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 →
0.13–0.7295% 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 →
±23.1%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, Tree Swallow in Alabama is projected to fall about 20% by 2030 — from 0.53 in 2025 to a central estimate of 0.42 (95% range 0.13–0.72). A 5-year backtest shows a typical error of ±23.1%, with 100% of held-out values landing inside the 95% band.19942030
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 →
20260.390.100.68
20270.400.100.69
20280.410.110.70
20290.420.120.71
20300.420.130.72

Tree Swallow Survey Routes in Alabama

Routes recording Tree 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 →
Guntersville1920172012
Oneonta1220252012
Riverside820132004
Drummond420242021
St Florian320242015
Maytown320251994
Kymulga320252019
Lakeview320242016
Swaim220171996
Pine Grove220252018
Greensport220252017
Carrollton219961996
Odenville220232009
Woodville220242015
Talladega220251996
Gastonburg220162016
Triana220122012
Trade120231995
Valhermoso Spgs120081999
Dawson119951995
Mt Olive120242021
Greensboro120212021
Borden Springs 2120132005
Whitehall120252008
Mentone120191996

Tree Swallow Population Trend in Other States

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

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