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

Tree Swallow Population Trend in Tennessee

All statesAerial insectivores

Tree Swallow in Tennessee has surged: up 15× on the route-weighted index since 1992.

15×Since 1992TrendPercent 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 →
39Routes 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 →
33YearsYears 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 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 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 Tennessee: up 15× on the route-weighted index since 1992.

Tree Swallow Population Forecast in Tennessee

If the recent trend holds, Tree Swallow in Tennessee is projected to rise about 50% by 2029 — from 1.5 in 2024 to a central estimate of 2.3 (95% range 1.5–3.0). A 5-year backtest shows a typical error of ±46.7%, with 40% of held-out values landing inside the 95% band.

+50%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 →
2.3Projected 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 →
1.5–3.095% 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 →
±46.7%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 Tennessee is projected to rise about 50% by 2029 — from 1.5 in 2024 to a central estimate of 2.3 (95% range 1.5–3.0). A 5-year backtest shows a typical error of ±46.7%, with 40% of held-out values landing inside the 95% band.19862029
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 →
20252.01.32.7
20262.11.42.8
20272.11.42.9
20282.21.52.9
20292.31.53.0

Tree Swallow Survey Routes in Tennessee

Routes recording Tree Swallow 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 →
Corryton Rd1020191992
Lovell920192007
Jefferson Cty920111992
Allens Brdge720231989
Belotes Bend620182009
Peytonsville620242004
Smokey Jct620222005
Jones Gap520162005
Tullahoma520152014
Mt Olive520242004
Mansfield420242001
Collinwood420242016
Lewis Forest420192008
Jasper420241997
Oliver Spgs420221998
Whiteville320132010
Signal Mtn220242005
Tiptonville220212000
Brownsville220002000
Cornpone220242002
Mecca220232016
Tellico220212021
Bradyville220032002
Glen220242004
Elk Valley220192004

Tree Swallow Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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