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

Vesper Sparrow Population Trend in Michigan

All statesGrassland birds

Vesper Sparrow in Michigan has collapsed: down 92% on the route-weighted index since 1968.

-92%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 →
98Routes 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 Vesper 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 →

Vesper Sparrow has collapsed in Michigan: down 92% on the route-weighted index since 1968.

Vesper Sparrow Population Forecast in Michigan

If the recent trend holds, Vesper Sparrow in Michigan is projected to fall about 100% by 2029 — from 0.62 in 2024 to a central estimate of 0.00 (95% range 0.00–2.1). A 5-year backtest shows a typical error of ±208.4%, with 60% 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 →
0.00–2.195% 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 →
±208.4%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, Vesper Sparrow in Michigan is projected to fall about 100% by 2029 — from 0.62 in 2024 to a central estimate of 0.00 (95% range 0.00–2.1). A 5-year backtest shows a typical error of ±208.4%, with 60% 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 →
20250.000.002.1
20260.000.002.1
20270.000.002.1
20280.000.002.1
20290.000.002.1

Vesper Sparrow Survey Routes in Michigan

Routes recording Vesper 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 →
Walloon Lake1820041977
Owendale1119941987
Irons1019861970
Maple Rapids1020231987
Riggsville920191967
Traverse Cty819921974
Pleasant Valley 2620242004
Ola520241974
Hubbard Lake519961973
New Buffalo520141992
Gooseneck520102008
Lawrence420221969
Big Rapids419901968
Nashville420231968
Remus420241974
St Charles420101967
Tyre419961967
Hamburg420001981
Creighton320181978
Belding320031983
Adrian320171966
Pettysville319791977
Cedar Run319941994
Hungerford320241991
Cluster Lakes320102006

Vesper Sparrow Population Trend in Other States

arizonacaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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