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Species · Michigan · BBS 2026 Release · 1966–2025

Black-throated Green Warbler Population Trend in Michigan

All statesForest birds

Black-throated Green Warbler in Michigan has surged: up 457% on the route-weighted index since 1968.

+457%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 →
70Routes 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 Black-throated Green 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 Green Warbler has surged in Michigan: up 457% on the route-weighted index since 1968.

Black-throated Green Warbler Population Forecast in Michigan

If the recent trend holds, Black-throated Green Warbler in Michigan is projected to rise about 63% by 2030 — from 2.9 in 2025 to a central estimate of 4.7 (95% range 2.9–6.6). A 5-year backtest shows a typical error of ±75.1%, with 0% of held-out values landing inside the 95% band.

+63%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 →
4.7Projected 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 →
2.9–6.695% 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 →
±75.1%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 Green Warbler in Michigan is projected to rise about 63% by 2030 — from 2.9 in 2025 to a central estimate of 4.7 (95% range 2.9–6.6). A 5-year backtest shows a typical error of ±75.1%, 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 →
20264.52.66.3
20274.52.76.4
20284.62.86.4
20294.72.86.5
20304.72.96.6

Black-throated Green Warbler Survey Routes in Michigan

Routes recording Black-throated Green 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 Lake2420191992
Ensign2220102006
Raco2020251971
Tahquamenon1620251974
Scott'S Marsh1620102006
Big Island Lake1620102008
Marenisco1420191981
Gooseneck1420102008
Hiawatha Nf1320251992
Gilchrist1220211974
Cluster Lakes1220102006
Ontonagon1020191970
Muskallonge1020241968
Sidnaw1020251993
Herman920221983
Ned Lake820251986
Shingleton820251967
Gibbs City720251979
Betchler Lks720251992
Isabella 2720252013
Ishpeming620251980
Bergland520221982
Crystal Fls520251979
Brocky Lake520251980
Isabella520121966

Black-throated Green Warbler Population Trend in Other States

alabamaarkansasconnecticutgeorgiaindianakentuckymainemarylandmassachusettsminnesotamissourinew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseevermontvirginiawest-virginiawisconsin

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