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

Chimney Swift Population Trend in Michigan

All statesAerial insectivores

Chimney Swift in Michigan has edged down: down 22% on the route-weighted index since 1968.

-22%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 →
93Routes 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 Chimney Swift 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 Chimney Swift in Michigan. See the full index history below.

Chimney Swift Population Forecast in Michigan

If the recent trend holds, Chimney Swift in Michigan is projected to stay roughly flat through 2029, near 1.5 (95% range 0.39–2.6). A 5-year backtest shows a typical error of ±12.2%, with 100% of held-out values landing inside the 95% band.

-9%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 →
1.5Projected 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 →
0.39–2.695% 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 →
±12.2%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 Michigan is projected to stay roughly flat through 2029, near 1.5 (95% range 0.39–2.6). A 5-year backtest shows a typical error of ±12.2%, 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 →
20251.60.462.7
20261.60.442.7
20271.50.422.6
20281.50.402.6
20291.50.392.6

Chimney Swift Survey Routes in Michigan

Routes recording Chimney Swift 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 →
Hamtramck3519841978
New Troy1120241971
Monterey1020241978
Lake City820221973
Belding820031983
Homer820211975
Crystal Fls720241979
Lawrence720241969
Holt720241969
Hamburg719951981
Hamburg 2720242004
Ontonagon619851969
Marenisco620141981
Traverse Cty619921974
Howardsville620231974
Mottville620241967
St Charles620191967
S Lyons619861966
Prattville520211967
Owendale520171978
North Branch519981974
Pettysville519771969
Deckerville520241978
Richmond520242000
Allegan Wma520191994

Chimney Swift Population Trend in Other States

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

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