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Species · Michigan · BBS 2025 Release · 1966–2024

Blue-gray Gnatcatcher Population Trend in Michigan

All statesForest birds

Blue-gray Gnatcatcher in Michigan has surged: up 650% on the route-weighted index since 1973.

+650%Since 1973TrendPercent 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 →
52Routes 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 →
52YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Blue-gray Gnatcatcher 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 →

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 →

Blue-gray Gnatcatcher has surged in Michigan: up 650% on the route-weighted index since 1973.

Blue-gray Gnatcatcher Population Forecast in Michigan

If the recent trend holds, Blue-gray Gnatcatcher in Michigan is projected to rise about 11% by 2029 — from 0.68 in 2024 to a central estimate of 0.76 (95% range 0.42–1.1). A 5-year backtest shows a typical error of ±55.6%, with 80% of held-out values landing inside the 95% band.

+11%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 →
0.76Projected 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 →
0.42–1.195% 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 →
±55.6%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, Blue-gray Gnatcatcher in Michigan is projected to rise about 11% by 2029 — from 0.68 in 2024 to a central estimate of 0.76 (95% range 0.42–1.1). A 5-year backtest shows a typical error of ±55.6%, with 80% of held-out values landing inside the 95% band.19692029
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 →
20250.710.371.0
20260.720.381.1
20270.730.391.1
20280.740.411.1
20290.760.421.1

Blue-gray Gnatcatcher Survey Routes in Michigan

Routes recording Blue-gray Gnatcatcher 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 →
Almena920151993
New Buffalo820141992
Bravo720231978
Allegan Wma520131993
Barry S.G.A.420121995
North Branch419961982
Belding 2320242015
Hamburg 2320242006
Monterey320241978
Mottville320241978
Rochester320241993
Cohoctah320242021
Scottville220222012
Skegemog Pt220241977
Nashville220241969
Howardsville220242003
Maple Rapids219941994
Adrian220172005
S Lyons219871973
Pettysville219771975
Harrietta120242004
Hungerford120242000
Chippewa Lk.120242014
Bear Lake119931993
Big Blue Lk120241984

Blue-gray Gnatcatcher Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsminnesotamississippimissourinebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawest-virginiawisconsinwyoming

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