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

Chimney Swift Population Trend in Tennessee

All statesAerial insectivores

Chimney Swift in Tennessee has fallen sharply: down 74% on the route-weighted index since 1968.

-74%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 →
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 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 fallen sharply in Tennessee: down 74% 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 24% by 2029 — from 3.9 in 2024 to a central estimate of 3.0 (95% range 0.00–7.6). A 5-year backtest shows a typical error of ±40.9%, with 100% of held-out values landing inside the 95% band.

-24%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 →
3.0Projected 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 →
0.00–7.695% 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 →
±40.9%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 24% by 2029 — from 3.9 in 2024 to a central estimate of 3.0 (95% range 0.00–7.6). A 5-year backtest shows a typical error of ±40.9%, 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 →
20254.00.008.6
20263.70.008.3
20273.50.008.1
20283.20.007.8
20293.00.007.6

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
Walland1519891966
Collinwood1220241966
Glen1120241966
Lovell1020191966
Belotes Bend920181966
Jefferson Cty920111966
Newfound Gap820241990
Silerton720241966
Jasper720241967
Oliver Spgs720221966
Pawpaw 2620222017
Pond Creek520241966
Indian Mound519981966
Cornpone520241990
Jones Gap520191982
Indian Mound 2520232004
Mansfield420241966
Humboldt420241966
Campbellsville420171966
Peytonsville420241966
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 2026-05-22.