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Species · Michigan · BBS 2025 Release · 1966–2024

Northern Waterthrush Population Trend in Michigan

All statesForest birds

Northern Waterthrush in Michigan has fallen sharply: down 68% on the route-weighted index since 1968.

-68%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 Northern Waterthrush 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 declinecomputed 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 →

Northern Waterthrush has fallen sharply in Michigan: down 68% on the route-weighted index since 1968.

Northern Waterthrush Population Forecast in Michigan

If the recent trend holds, Northern Waterthrush in Michigan is projected to fall about 41% by 2029 — from 0.23 in 2024 to a central estimate of 0.14 (95% range 0.00–0.48). A 5-year backtest shows a typical error of ±59.9%, with 80% of held-out values landing inside the 95% band.

-41%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 →
0.14Projected 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 →
0.00–0.4895% 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 →
±59.9%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, Northern Waterthrush in Michigan is projected to fall about 41% by 2029 — from 0.23 in 2024 to a central estimate of 0.14 (95% range 0.00–0.48). A 5-year backtest shows a typical error of ±59.9%, 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 →
20250.150.000.50
20260.150.000.49
20270.140.000.49
20280.140.000.48
20290.140.000.48

Northern Waterthrush Survey Routes in Michigan

Routes recording Northern Waterthrush 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 →
Marenisco1120191981
Brush Creek820121977
Hubbard Lake719961973
Isabella420041975
Walloon Lake 2320242005
Gilchrist320211977
Ensign320082006
Bergland220191979
Bootjack219701969
Ishpeming219941981
Brocky Lake220231980
Wilson220101966
Big Island Lake220102010
Big Rapids219891989
Ned Lake120221988
Herman119931983
Crystal Fls120221984
Gibbs City120171985
Maple Grove120241970
Cunard120191974
Shingleton120181967
Creighton120231978
Bear Lake120191971
Scottville119771977
Big Blue Lk119991985

Northern Waterthrush Population Trend in Other States

alaskaconnecticutidahomainemarylandmassachusettsminnesotamontananew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiopennsylvaniarhode-islandvermontvirginiawashingtonwest-virginiawisconsinwyoming

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