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Species · Michigan · BBS 2025 Release · 1966–2024

Black-throated Blue Warbler Population Trend in Michigan

All statesForest birds

Black-throated Blue Warbler in Michigan has surged: up 668% on the route-weighted index since 1973.

+668%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 →
49Routes 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 →
53YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Black-throated Blue Warbler 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 →

Black-throated Blue Warbler has surged in Michigan: up 668% on the route-weighted index since 1973.

Black-throated Blue Warbler Population Forecast in Michigan

If the recent trend holds, Black-throated Blue Warbler in Michigan is projected to stay roughly flat through 2029, near 0.74 (95% range 0.49–0.99). A 5-year backtest shows a typical error of ±29.8%, with 60% of held-out values landing inside the 95% band.

+5%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 →
0.74Projected 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 →
0.49–0.9995% 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 →
±29.8%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, Black-throated Blue Warbler in Michigan is projected to stay roughly flat through 2029, near 0.74 (95% range 0.49–0.99). A 5-year backtest shows a typical error of ±29.8%, with 60% of held-out values landing inside the 95% band.19672029
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 →
20250.690.440.94
20260.700.450.95
20270.710.470.96
20280.730.480.98
20290.740.490.99

Black-throated Blue Warbler Survey Routes in Michigan

Routes recording Black-throated Blue Warbler 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 →
Imp Lake920191994
Sidnaw820241993
Hiawatha Nf820241992
Scott'S Marsh720102006
Cluster Lakes620092006
Brocky Lake420241981
Raco320241987
Betchler Lks320241993
Ontonagon220191969
Cunard219861986
Shingleton220231967
Tahquamenon220241974
Ensign220092006
Harrietta120051990
Bergland120221989
Marenisco120181981
Bootjack120172017
Ned Lake120241986
Herman120221984
Crystal Fls119901990
Gibbs City120241987
Maple Grove120191981
Ishpeming120231981
Wilson119951995
Creighton120191978

Black-throated Blue Warbler Population Trend in Other States

connecticutgeorgiamainemarylandmassachusettsminnesotanew-hampshirenew-jerseynew-yorknorth-carolinapennsylvaniarhode-islandtennesseevermontvirginiawest-virginiawisconsin

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