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Species · Michigan · BBS 2025 Release · 1966–2024

Tree Swallow Population Trend in Michigan

All statesAerial insectivores

Tree Swallow in Michigan has held roughly steady: down 6% on the route-weighted index since 1968.

-6%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 →
104Routes 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 →
58YearsYears 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 MichiganNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Tree Swallow in Michigan. See the full index history below.

Tree Swallow Population Forecast in Michigan

If the recent trend holds, Tree Swallow in Michigan is projected to rise about 15% by 2029 — from 3.8 in 2024 to a central estimate of 4.4 (95% range 0.00–9.8). A 5-year backtest shows a typical error of ±68.4%, with 100% of held-out values landing inside the 95% band.

+15%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 →
4.4Projected 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 →
0.00–9.895% 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 →
±68.4%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, Tree Swallow in Michigan is projected to rise about 15% by 2029 — from 3.8 in 2024 to a central estimate of 4.4 (95% range 0.00–9.8). A 5-year backtest shows a typical error of ±68.4%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20254.70.0010
20264.60.0010
20274.60.0010.0
20284.50.009.9
20294.40.009.8

Tree Swallow Survey Routes in Michigan

Routes recording Tree Swallow in Michigan.
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 →
Herron4020162011
Hamburg 22720242004
Frederic2320031971
Cathro1720161967
Cunard1620211973
Pleasant Val1619971967
Pickford1520241973
Richmond1520241999
Cedar Run1419991994
Hamburg1420001985
Lake City1320221970
Nashville1320241968
Rochester1320241993
Big Rapids1119901971
Chippewa Lk.1120241992
Bootjack1020231967
Riggsville1020191967
Skeels1020151966
North Branch1019991974
Adrian920182004
Drayton Plns919871973
Monterey820151979
St Charles820191967
Beaver Lake820111967
Frederic 2820172004

Tree Swallow Population Trend in Other States

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

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