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

Tree Swallow Population Trend in Missouri

All statesAerial insectivores

Tree Swallow in Missouri has surged: up 161% on the route-weighted index since 1974.

+161%Since 1974TrendPercent 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 →
70Routes 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 →
49YearsYears 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 MissouriNotable 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 Missouri: up 161% on the route-weighted index since 1974.

Tree Swallow Population Forecast in Missouri

If the recent trend holds, Tree Swallow in Missouri is projected to rise about 54% by 2029 — from 0.45 in 2024 to a central estimate of 0.69 (95% range 0.33–1.1). A 5-year backtest shows a typical error of ±24.8%, with 100% of held-out values landing inside the 95% band.

+54%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 →
0.69Projected 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 →
0.33–1.195% 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 →
±24.8%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 Missouri is projected to rise about 54% by 2029 — from 0.45 in 2024 to a central estimate of 0.69 (95% range 0.33–1.1). A 5-year backtest shows a typical error of ±24.8%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20250.650.291.0
20260.660.301.0
20270.670.311.0
20280.680.321.0
20290.690.331.1

Tree Swallow Survey Routes in Missouri

Routes recording Tree Swallow in Missouri.
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 →
Eugene1020242014
Graniteville920182006
Queen City820222017
Watson720152006
Rensselaer620041993
New Hampton520212014
Tarkio519791979
House Springs520232017
Lucerne420182018
Sedalia420152009
Pulaski320161975
Akers320121989
Wesco320232013
Filley320181989
Sni Mills319691969
Madison320242007
Sticklervill320231976
West Plains320172017
Osage Beach320231999
Kirksville320172002
New Point320232002
Palace320222022
Norborne220212021
Cascade220242023
Elmo220222017

Tree Swallow Population Trend in Other States

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

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