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Species · Michigan · BBS 2026 Release · 1966–2025

Chestnut-sided Warbler Population Trend in Michigan

All statesForest birds

Chestnut-sided Warbler in Michigan has surged: up 113% on the route-weighted index since 1968.

+113%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 →
92Routes 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 Chestnut-sided 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 →

Chestnut-sided Warbler has surged in Michigan: up 113% on the route-weighted index since 1968.

Chestnut-sided Warbler Population Forecast in Michigan

If the recent trend holds, Chestnut-sided Warbler in Michigan is projected to fall about 29% by 2030 — from 4.4 in 2025 to a central estimate of 3.1 (95% range 1.7–4.6). A 5-year backtest shows a typical error of ±26.2%, with 60% of held-out values landing inside the 95% band.

-29%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 →
3.1Projected 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 →
1.7–4.695% 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 →
±26.2%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, Chestnut-sided Warbler in Michigan is projected to fall about 29% by 2030 — from 4.4 in 2025 to a central estimate of 3.1 (95% range 1.7–4.6). A 5-year backtest shows a typical error of ±26.2%, with 60% 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 →
20263.11.64.5
20273.11.74.5
20283.11.74.5
20293.11.74.6
20303.11.74.6

Chestnut-sided Warbler Survey Routes in Michigan

Routes recording Chestnut-sided 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 Lake2320251986
Brocky Lake2120251980
Raco1720251971
Marenisco1520191981
Herman1520221983
Maple Grove1520251969
Pickford1520251974
Tahquamenon1220251974
Ishpeming1120251980
Shingleton1120251967
Isabella 21120252017
Crystal Fls1020251979
Gibbs City1020251979
Imp Lake1020191992
Ontonagon920191967
Hubbard Lake919961975
Muskallonge620241966
Gilchrist620211974
Cathro620081967
Sidnaw620251993
Scott'S Marsh620102006
Bootjack520231967
Scottville520251971
Walloon Lake 2520242005
Cluster Lakes520102006

Chestnut-sided Warbler Population Trend in Other States

alabamaarkansascoloradoconnecticutgeorgiaillinoisindianaiowakansaskentuckymainemarylandmassachusettsminnesotanevadanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiopennsylvaniarhode-islandtennesseevermontvirginiawest-virginiawisconsinwyoming

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