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Species · Michigan · BBS 2025 Release · 1966–2024

Nashville Warbler Population Trend in Michigan

All statesForest birds

Nashville Warbler in Michigan has surged: up 670% on the route-weighted index since 1968.

+670%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 →
67Routes 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 →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Nashville 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 →

Nashville Warbler has surged in Michigan: up 670% on the route-weighted index since 1968.

Nashville Warbler Population Forecast in Michigan

If the recent trend holds, Nashville Warbler in Michigan is projected to rise about 47% by 2029 — from 6.7 in 2024 to a central estimate of 9.9 (95% range 6.6–13). A 5-year backtest shows a typical error of ±31.2%, with 60% of held-out values landing inside the 95% band.

+47%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 →
9.9Projected 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 →
6.6–1395% 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 →
±31.2%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, Nashville Warbler in Michigan is projected to rise about 47% by 2029 — from 6.7 in 2024 to a central estimate of 9.9 (95% range 6.6–13). A 5-year backtest shows a typical error of ±31.2%, with 60% of held-out values landing inside the 95% band.19662029
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 →
20259.36.113
20269.56.213
20279.66.413
20289.76.513
20299.96.613

Nashville Warbler Survey Routes in Michigan

Routes recording Nashville 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 →
Brocky Lake7020241980
Betchler Lks4120241992
Ishpeming3920231980
Muskallonge3120241966
Sidnaw3020241993
Ontonagon2920191967
Creighton2520231978
Brush Creek2320161975
Ned Lake2120241986
Raco2020241971
Imp Lake1920191992
Gibbs City1820241979
Hubbard Lake1819961975
Ensign1820102006
Bergland1720221979
Tahquamenon1720241974
Cluster Lakes1720102006
Herman1520221983
Wilson1520101975
Gooseneck1320102008
Isabella1220091966
Isabella 21220242013
Big Island Lake1120102008
Crystal Fls1020241985
Gilchrist1020211974

Nashville Warbler Population Trend in Other States

californiaconnecticutidahomainemarylandmassachusettsminnesotamontananew-hampshirenew-jerseynew-yorknorth-dakotaoregonpennsylvaniarhode-islandvermontvirginiawashingtonwest-virginiawisconsin

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