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

Chimney Swift Population Trend in Tennessee

All statesAerial insectivores

Chimney Swift in Tennessee has collapsed: down 76% on the route-weighted index since 1968.

-76%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 →
55Routes 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 →
59YearsYears 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 TennesseeNotable 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 collapsed in Tennessee: down 76% on the route-weighted index since 1968.

Chimney Swift Population Forecast in Tennessee

If the recent trend holds, Chimney Swift in Tennessee is projected to fall about 15% by 2030 — from 3.1 in 2025 to a central estimate of 2.6 (95% range 0.00–7.2). A 5-year backtest shows a typical error of ±40%, with 100% of held-out values landing inside the 95% band.

-15%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 →
2.6Projected 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 →
0.00–7.295% 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 →
±40%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 Tennessee is projected to fall about 15% by 2030 — from 3.1 in 2025 to a central estimate of 2.6 (95% range 0.00–7.2). A 5-year backtest shows a typical error of ±40%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20263.70.008.2
20273.40.008.0
20283.20.007.7
20292.90.007.5
20302.60.007.2

Chimney Swift Survey Routes in Tennessee

Routes recording Chimney Swift in Tennessee.
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 →
Climer5220041967
Corryton Rd4420191966
Red Bank2219781966
Soddy2019811967
Peytonsville1520251966
Walland1519891966
Lovell1020191966
Belotes Bend920181966
Jefferson Cty920111966
Newfound Gap820241990
Silerton720241966
Humboldt720251966
Jasper720251967
Oliver Spgs720221966
Pawpaw 2620222017
Indian Mound519981966
Cornpone520241990
Cades Cove520252004
Jones Gap520191982
Indian Mound 2520232004
Mansfield420251966
Pond Creek420251966
Collinwood420251966
Campbellsville420171966
Mt Olive420241966

Chimney Swift Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatexasvermontvirginiawest-virginiawisconsinwyoming

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