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

Winter Wren Population Trend in Michigan

All statesForest birds

Winter Wren in Michigan has surged: up 541% on the route-weighted index since 1968.

+541%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 →
59Routes 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 Winter Wren 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 →

Winter Wren has surged in Michigan: up 541% on the route-weighted index since 1968.

Winter Wren Population Forecast in Michigan

If the recent trend holds, Winter Wren in Michigan is projected to rise about 59% by 2029 — from 1.5 in 2024 to a central estimate of 2.4 (95% range 1.3–3.5). A 5-year backtest shows a typical error of ±46.7%, with 80% of held-out values landing inside the 95% band.

+59%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 →
2.4Projected 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 →
1.3–3.595% 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 →
±46.7%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, Winter Wren in Michigan is projected to rise about 59% by 2029 — from 1.5 in 2024 to a central estimate of 2.4 (95% range 1.3–3.5). A 5-year backtest shows a typical error of ±46.7%, with 80% 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 →
20252.31.23.4
20262.31.23.4
20272.41.33.5
20282.41.33.5
20292.41.33.5

Winter Wren Survey Routes in Michigan

Routes recording Winter Wren 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 →
Gibbs City2320241982
Marenisco920191981
Brocky Lake920241980
Maple Grove820241967
Ishpeming620231980
Muskallonge620241977
Cedar Run519991999
Gooseneck520092008
Walloon Lake520041977
Imp Lake520191992
Pine River520211992
Hiawatha Nf520241992
Seney Nwr520231992
Pleasant Valley 2520242009
Herman420221983
Ensign420102006
Big Island Lake420102008
Ned Lake320241986
Crystal Fls320241988
Wilson320101966
Walloon Lake 2320242005
Scott'S Marsh320102006
Tahquamenon320241974
Gilchrist320211974
Skegemog Pt320141974

Winter Wren Population Trend in Other States

connecticutmainemarylandmassachusettsminnesotanew-hampshirenew-jerseynew-yorknorth-carolinaohiopennsylvaniatennesseevermontvirginiawest-virginiawisconsin

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