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Species · Michigan · BBS 2026 Release · 1966–2025

Magnolia Warbler Population Trend in Michigan

All statesForest birds

Magnolia Warbler in Michigan has surged: up 12× on the route-weighted index since 1974.

12×Since 1974TrendPercent 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 Magnolia 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 →

Magnolia Warbler has surged in Michigan: up 12× on the route-weighted index since 1974.

Magnolia Warbler Population Forecast in Michigan

If the recent trend holds, Magnolia Warbler in Michigan is projected to rise about 21% by 2030 — from 0.82 in 2025 to a central estimate of 0.99 (95% range 0.49–1.5). A 5-year backtest shows a typical error of ±82.8%, with 60% of held-out values landing inside the 95% band.

+21%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 →
0.99Projected 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 →
0.49–1.595% 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 →
±82.8%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, Magnolia Warbler in Michigan is projected to rise about 21% by 2030 — from 0.82 in 2025 to a central estimate of 0.99 (95% range 0.49–1.5). A 5-year backtest shows a typical error of ±82.8%, with 60% of held-out values landing inside the 95% band.19712030
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 →
20260.940.451.4
20270.950.461.4
20280.960.471.5
20290.970.481.5
20300.990.491.5

Magnolia Warbler Survey Routes in Michigan

Routes recording Magnolia 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 →
Ned Lake820251986
Herman720221983
Gibbs City720251985
Ensign520102006
Ontonagon420191971
Ishpeming420251980
Brocky Lake420251980
Tahquamenon420251975
Betchler Lks420241992
Bootjack320231986
Raco320251971
Pine River320181992
Marenisco220191981
Big Blue Lk219931984
Scott'S Marsh220102006
Gilchrist220211986
Pleasant Val219961996
Pickford220241990
Frederic220011988
Cluster Lakes220102006
Harrietta120172017
Bergland120221979
Crystal Fls120252010
Maple Grove120251981
Wilson120091993

Magnolia Warbler Population Trend in Other States

connecticutmainemarylandmassachusettsminnesotanew-hampshirenew-jerseynew-yorknorth-carolinaohiopennsylvaniavermontvirginiawest-virginiawisconsin

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