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Species · Michigan · BBS 2025 Release · 1966–2024

Henslow's Sparrow Population Trend in Michigan

All statesGrassland birds

Henslow's Sparrow in Michigan has collapsed: down 95% on the route-weighted index since 1968.

-95%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 →
36Routes 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 →
43YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Henslow's Sparrow 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 →

Henslow's Sparrow has collapsed in Michigan: down 95% on the route-weighted index since 1968.

Henslow's Sparrow Population Forecast in Michigan

If the recent trend holds, Henslow's Sparrow in Michigan is projected to stay roughly flat through 2019, near 0.00 (95% range 0.00–0.37). A 5-year backtest shows a typical error of ±956.2%, with 80% of held-out values landing inside the 95% band.

n/aChange by 2019TrendPercent 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 2019 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.3795% 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 →
±956.2%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, Henslow's Sparrow in Michigan is projected to stay roughly flat through 2019, near 0.00 (95% range 0.00–0.37). A 5-year backtest shows a typical error of ±956.2%, with 80% of held-out values landing inside the 95% band.19662019
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 →
20150.000.000.37
20160.000.000.37
20170.000.000.37
20180.000.000.37
20190.000.000.37

Henslow's Sparrow Survey Routes in Michigan

Routes recording Henslow's Sparrow 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 →
Holt919721971
Juniata719791978
Deckerville320012000
New Buffalo220132008
Lawrence219791970
Bravo219851974
Galesburg220111966
Hungerford120062006
Ned Lake120082008
Maple Grove119851984
Wilson119841982
Cunard120041984
Almena120091993
New Troy120141971
Pleasant Val119911991
Lake City120081975
Big Rapids119901967
Nashville120131968
Coopersville120012001
Belding119921983
Howardsville120131969
Remus120001974
Mottville119681968
Hamburg119911981
Skeels120001968

Henslow's Sparrow Population Trend in Other States

delawareillinoisindianaiowakansaskentuckymarylandminnesotamissourinebraskanew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniasouth-dakotavermontvirginiawest-virginiawisconsin

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