BirdAnalyst
Species · Ohio · BBS 2026 Release · 1966–2025

Chimney Swift Population Trend in Ohio

All statesAerial insectivores

Chimney Swift in Ohio has fallen sharply: down 65% on the route-weighted index since 1968.

-65%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 →
89Routes 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 →
59YearsYears 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 OhioNotable 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 fallen sharply in Ohio: down 65% on the route-weighted index since 1968.

Chimney Swift Population Forecast in Ohio

If the recent trend holds, Chimney Swift in Ohio is projected to fall about 14% by 2030 — from 7.1 in 2025 to a central estimate of 6.2 (95% range 0.00–13). A 5-year backtest shows a typical error of ±38.4%, with 100% of held-out values landing inside the 95% band.

-14%Change by 2030TrendPercent 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 →
6.2Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–1395% 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 →
±38.4%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 Ohio is projected to fall about 14% by 2030 — from 7.1 in 2025 to a central estimate of 6.2 (95% range 0.00–13). A 5-year backtest shows a typical error of ±38.4%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20267.00.0514
20276.80.0014
20286.60.0014
20296.40.0013
20306.20.0013

Chimney Swift Survey Routes in Ohio

Routes recording Chimney Swift in Ohio.
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 →
Dunlap7719881966
Tecumseh7019821966
Coal Run4119921966
Smithfield3820251966
Newcomerstwn3519951966
Harveysburg3519961966
Wilmington3519961966
Westerville3019851966
Bismark2819951967
Troy2819961966
Garrettsvile2519911966
Stonecreek2420251996
Baxter Ridge2320251998
Winterset2119831967
Botkins2020191992
W Carrollton2020151989
West Elkton1820121992
Lattasburg1720251966
Peru1619781966
Cumberland1420171966
Birmingham1420241988
Marion1320231966
Dresden1320251966
Bolins Mills1320251966
Napoleon1220251966

Chimney Swift Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaoklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.