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Species · Michigan · BBS 2025 Release · 1966–2024

Blackburnian Warbler Population Trend in Michigan

All statesForest birds

Blackburnian Warbler in Michigan has surged: up 485% on the route-weighted index since 1968.

+485%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 →
55Routes 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 Blackburnian 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 →

Blackburnian Warbler has surged in Michigan: up 485% on the route-weighted index since 1968.

Blackburnian Warbler Population Forecast in Michigan

If the recent trend holds, Blackburnian Warbler in Michigan is projected to rise about 64% by 2029 — from 1.1 in 2024 to a central estimate of 1.8 (95% range 1.1–2.5). A 5-year backtest shows a typical error of ±53.9%, with 60% of held-out values landing inside the 95% band.

+64%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 →
1.8Projected 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 →
1.1–2.595% 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 →
±53.9%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, Blackburnian Warbler in Michigan is projected to rise about 64% by 2029 — from 1.1 in 2024 to a central estimate of 1.8 (95% range 1.1–2.5). A 5-year backtest shows a typical error of ±53.9%, 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 →
20251.71.02.4
20261.71.12.4
20271.81.12.4
20281.81.12.5
20291.81.12.5

Blackburnian Warbler Survey Routes in Michigan

Routes recording Blackburnian 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 →
Bergland1620221982
Imp Lake1620191992
Marenisco820191981
Raco720241972
Herman620131984
Gibbs City620241979
Crystal Fls520241979
Tahquamenon520241974
Gilchrist520211976
Scott'S Marsh520102006
Cluster Lakes520102006
Harrietta420241996
Maple Grove420241967
Ishpeming420231981
Shingleton420241967
Ensign420102006
Sidnaw320241993
Ontonagon220191969
Bootjack220211967
Ned Lake220241986
Brocky Lake220241981
Walloon Lake 2220242007
Barry S.G.A.220062006
Muskallonge220241966
Big Island Lake220102008

Blackburnian Warbler Population Trend in Other States

connecticutgeorgiaindianamainemarylandmassachusettsminnesotanew-hampshirenew-jerseynew-yorknorth-carolinaohiopennsylvaniarhode-islandtennesseevermontvirginiawest-virginiawisconsin

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