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

Pine Warbler Population Trend in Michigan

All statesForest birds

Pine Warbler in Michigan has surged: up 39× on the route-weighted index since 1969.

39×Since 1969TrendPercent 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 →
77Routes 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 Pine 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 →

Pine Warbler has surged in Michigan: up 39× on the route-weighted index since 1969.

Pine Warbler Population Forecast in Michigan

If the recent trend holds, Pine Warbler in Michigan is projected to stay roughly flat through 2029, near 2.9 (95% range 1.9–3.8). A 5-year backtest shows a typical error of ±18.3%, 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 →
2.9Projected 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 →
1.9–3.895% 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 →
±18.3%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, Pine Warbler in Michigan is projected to stay roughly flat through 2029, near 2.9 (95% range 1.9–3.8). A 5-year backtest shows a typical error of ±18.3%, with 100% 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 →
20252.71.83.6
20262.71.83.7
20272.81.83.7
20282.81.93.8
20292.91.93.8

Pine Warbler Survey Routes in Michigan

Routes recording Pine 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 →
Betchler Lks1620241992
Gibbs City1420241985
Muskallonge1220241968
Red Oak1220221985
Cluster Lakes1220102006
Imp Lake1120191992
Big Island Lake1120102008
Gooseneck1020102008
Seney Nwr920241992
Tahquamenon820241976
Irons819891989
Walloon Lake 2720242005
Ensign720102006
Crystal Fls620241988
Frederic620011971
Sand Lake620241978
Brocky Lake520241980
Gilchrist520211987
Sidnaw520241993
Herman420221983
Ishpeming420231980
Big Blue Lk420241998
Lake City420222004
Monterey420241980
Hungerford420241995

Pine Warbler Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiaillinoisindianakentuckylouisianamainemarylandmassachusettsminnesotamississippimissourinew-hampshirenew-jerseynew-yorknorth-carolinaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvermontvirginiawest-virginiawisconsin

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