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

Tree Swallow Population Trend in Ohio

All statesAerial insectivores

Tree Swallow in Ohio has surged: up 602% on the route-weighted index since 1968.

+602%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 →
81Routes 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 Tree Swallow 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 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 Ohio: up 601% on the route-weighted index since 1968.

Tree Swallow Population Forecast in Ohio

If the recent trend holds, Tree Swallow in Ohio is projected to rise about 46% by 2030 — from 2.2 in 2025 to a central estimate of 3.2 (95% range 1.9–4.4). A 5-year backtest shows a typical error of ±81.9%, with 0% of held-out values landing inside the 95% band.

+46%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 →
3.2Projected 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 →
1.9–4.495% 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 →
±81.9%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 Ohio is projected to rise about 46% by 2030 — from 2.2 in 2025 to a central estimate of 3.2 (95% range 1.9–4.4). A 5-year backtest shows a typical error of ±81.9%, with 0% 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 →
20263.01.74.3
20273.01.84.3
20283.11.84.3
20293.11.94.4
20303.21.94.4

Tree Swallow Survey Routes in Ohio

Routes recording Tree Swallow 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 →
Garrettsvile2419911967
Marion1620231968
Birmingham1520191988
Kunkle1020241995
Graytown1019841966
Kings Creek920151992
Kenton920251990
Hiram820251992
Kingsway720251971
Troy719931966
Adamsville719881988
Cuba720231992
Hebron720251985
Napoleon620251967
Marion 2620252024
Botkins520191995
Cosmos520191995
New Dover520221988
New Somerset519881974
Rome520211987
Ashley520181988
Omega420241967
Cumberland420171993
Ash Ridge420181996
Vickery420251996

Tree Swallow Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaoklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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