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

Northern Rough-winged Swallow Population Trend in Tennessee

All statesAerial insectivores

Northern Rough-winged Swallow in Tennessee has surged: up 219% on the route-weighted index since 1968.

+219%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 →
51Routes 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 Northern Rough-winged 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 →

Northern Rough-winged Swallow has surged in Tennessee: up 219% on the route-weighted index since 1968.

Northern Rough-winged Swallow Population Forecast in Tennessee

If the recent trend holds, Northern Rough-winged Swallow in Tennessee is projected to rise about 11% by 2029 — from 3.3 in 2024 to a central estimate of 3.7 (95% range 2.2–5.1). A 5-year backtest shows a typical error of ±32.2%, with 60% of held-out values landing inside the 95% band.

+11%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 →
3.7Projected 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 →
2.2–5.195% 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 →
±32.2%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, Northern Rough-winged Swallow in Tennessee is projected to rise about 11% by 2029 — from 3.3 in 2024 to a central estimate of 3.7 (95% range 2.2–5.1). A 5-year backtest shows a typical error of ±32.2%, with 60% 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 →
20253.52.15.0
20263.62.15.0
20273.62.25.1
20283.62.25.1
20293.72.25.1

Northern Rough-winged Swallow Survey Routes in Tennessee

Routes recording Northern Rough-winged 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 →
Campbellsville8220191967
Tullahoma2220151971
White House1520191977
Pond Creek1420241966
Pawpaw1120091969
Mcfarland1019931967
Whiteville920241974
Mansfield820241970
Humboldt820241986
Glen820241970
Lovell820191967
Mecca820141995
Peytonsville720241971
Brownsville520231974
Tibbs520241967
Climer520021967
Trenton420112002
Moscow320241991
Sweetlips320181971
Silerton320241966
Fish Springs320171967
Signal Mtn220241979
Big Sandy220231971
Indian Mound219981968
Wrigley220221972

Northern Rough-winged 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.