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

Chimney Swift Population Trend in Missouri

All statesAerial insectivores

Chimney Swift in Missouri has collapsed: down 88% on the route-weighted index since 1969.

-88%Since 1969TrendPercent 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 →
91Routes 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 →
57YearsYears 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 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 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 collapsed in Missouri: down 88% on the route-weighted index since 1969.

Chimney Swift Population Forecast in Missouri

If the recent trend holds, Chimney Swift in Missouri is projected to fall about 100% by 2029 — from 0.69 in 2024 to a central estimate of 0.00 (95% range 0.00–2.5). A 5-year backtest shows a typical error of ±28.4%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–2.595% 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 →
±28.4%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 Missouri is projected to fall about 100% by 2029 — from 0.69 in 2024 to a central estimate of 0.00 (95% range 0.00–2.5). A 5-year backtest shows a typical error of ±28.4%, with 100% 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 →
20250.660.003.2
20260.480.003.0
20270.290.002.8
20280.110.002.6
20290.000.002.5

Chimney Swift Survey Routes in Missouri

Routes recording Chimney Swift 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 →
Cole Camp4419901971
Sni Mills3319901967
Gildehouse2919891978
Hamilton2219851972
Syracuse1720231969
Graydon1520221968
Kirksville920171994
Watson920231991
Union919991990
Washington819771967
Centertown820231973
Sedalia820231991
Gerald720222013
Kahoka619981967
Deventer520241967
Clementine520021974
Madison520221971
Rockingham520161969
Marshfield520161996
Millwood520221999
Clementine 2520062005
House Springs520232017
Cassville420241972
Bolckow419921967
Bennett420221997

Chimney Swift Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimontananebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

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