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Species · Kansas · BBS 2025 Release · 1966–2024

Tree Swallow Population Trend in Kansas

All statesAerial insectivores

Tree Swallow in Kansas has surged: up 671% on the route-weighted index since 1977.

+671%Since 1977TrendPercent 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 →
33Routes 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 KansasNotable 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 Kansas: up 671% on the route-weighted index since 1977.

Tree Swallow Population Forecast in Kansas

If the recent trend holds, Tree Swallow in Kansas is projected to fall about 53% by 2029 — from 0.50 in 2024 to a central estimate of 0.24 (95% range 0.01–0.46). A 5-year backtest shows a typical error of ±44.3%, with 80% of held-out values landing inside the 95% band.

-53%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 →
0.24Projected 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 →
0.01–0.4695% 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 →
±44.3%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 Kansas is projected to fall about 53% by 2029 — from 0.50 in 2024 to a central estimate of 0.24 (95% range 0.01–0.46). A 5-year backtest shows a typical error of ±44.3%, with 80% of held-out values landing inside the 95% band.19672029
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 →
20250.220.000.45
20260.230.000.45
20270.230.000.45
20280.230.010.46
20290.240.010.46

Tree Swallow Survey Routes in Kansas

Routes recording Tree Swallow in Kansas.
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 →
Pittsburg1320122001
Trading Post620242011
Rock Creek 2620242022
Olsburg520172000
St John420162016
Jewell 2320102008
Severance320232003
Lapland220152007
Rock Creek220141989
Seneca220222007
Covert220132004
Galesburg120091996
Wellington120062006
Olathe120211967
Dover120212008
Barclay120092009
Ellinor120072007
Albert119821977
Kanopolis120241972
Grantville120192019
Hollenberg120192019
Gove120122012
Beloit 2120132013
Morehead120192019
Reece120072007

Tree Swallow Population Trend in Other States

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

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