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

Herring Gull Population Trend in Michigan

All statesWetland birds

Herring Gull in Michigan has collapsed: down 94% on the route-weighted index since 1968.

-94%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 →
40Routes 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 Herring Gull 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 →

Herring Gull has collapsed in Michigan: down 94% on the route-weighted index since 1968.

Herring Gull Population Forecast in Michigan

If the recent trend holds, Herring Gull in Michigan is projected to fall about 100% by 2029 — from 0.26 in 2024 to a central estimate of 0.00 (95% range 0.00–4.2). A 5-year backtest shows a typical error of ±57.3%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–4.295% 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 →
±57.3%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, Herring Gull in Michigan is projected to fall about 100% by 2029 — from 0.26 in 2024 to a central estimate of 0.00 (95% range 0.00–4.2). A 5-year backtest shows a typical error of ±57.3%, 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 →
20250.060.004.2
20260.000.004.2
20270.000.004.2
20280.000.004.2
20290.000.004.2

Herring Gull Survey Routes in Michigan

Routes recording Herring Gull 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 →
Cathro10020161970
Adair3319871985
Lake City2619981998
St Charles1919921992
Hiawatha Nf1420221993
Pickford1020241973
Tahquamenon620101990
Skegemog Pt620191986
Herman420131983
Wilson420051982
Richmond420142003
Creighton319891981
Isabella320041966
Ontonagon220171985
Bergland220151989
Bootjack220161967
Cunard220042004
Walloon Lake 2220102007
Gilchrist220181977
Herron220132011
Raco219941992
Hubbard Lake219961992
Hamtramck219841978
Deckerville220161980
Gibbs City119921992

Herring Gull Population Trend in Other States

alabamaalaskacaliforniacoloradoconnecticutdelawarefloridaidahoillinoisindianakansaslouisianamainemarylandmassachusettsminnesotamontananew-hampshirenew-jerseynew-yorknorth-carolinaohiooregonpennsylvaniarhode-islandsouth-carolinatexasvermontvirginiawashingtonwest-virginiawisconsin

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