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

Black Tern Population Trend in Michigan

All statesWetland birds

Black Tern in Michigan has collapsed: down 96% on the route-weighted index since 1968.

-96%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 →
17Routes 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 →
49YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Black Tern 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 →

Black Tern has collapsed in Michigan: down 96% on the route-weighted index since 1968.

Black Tern Population Forecast in Michigan

If the recent trend holds, Black Tern in Michigan is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±58.7%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.00Projected 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 →
0.00–0.3495% 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 →
±58.7%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, Black Tern in Michigan is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±58.7%, with 100% 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 →
20250.000.000.34
20260.000.000.34
20270.000.000.34
20280.000.000.34
20290.000.000.34

Black Tern Survey Routes in Michigan

Routes recording Black Tern 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 →
Bergland619821982
Big Blue Lk519901990
Monterey420081988
Pickford319811981
Remus219901990
Nashville119701968
Galesburg119891966
Howardsville119821970
Mottville119911968
S Lyons119851985
Hartland119981998
Chippewa Lk.120221992
Seney Nwr120061992
Allegan Wma119931993
No Bradley120242024
Tahquamenon119881979
Prattville119971987

Black Tern Population Trend in Other States

californiacoloradoidahoillinoisindianaiowakansasmaineminnesotamissourimontananebraskanevadanew-yorknorth-dakotaohiooregonsouth-dakotatexasutahwashingtonwisconsinwyoming

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