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Species · Michigan · BBS 2025 Release · 1966–2024

Savannah Sparrow Population Trend in Michigan

All statesGrassland birds

Savannah Sparrow in Michigan has collapsed: down 85% on the route-weighted index since 1968.

-85%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 →
97Routes 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 Savannah 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 →

Savannah Sparrow has collapsed in Michigan: down 85% on the route-weighted index since 1968.

Savannah Sparrow Population Forecast in Michigan

If the recent trend holds, Savannah Sparrow in Michigan is projected to fall about 48% by 2029 — from 3.5 in 2024 to a central estimate of 1.8 (95% range 0.00–5.2). A 5-year backtest shows a typical error of ±58.3%, with 100% of held-out values landing inside the 95% band.

-48%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 →
1.8Projected 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 →
0.00–5.295% 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 →
±58.3%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, Savannah Sparrow in Michigan is projected to fall about 48% by 2029 — from 3.5 in 2024 to a central estimate of 1.8 (95% range 0.00–5.2). A 5-year backtest shows a typical error of ±58.3%, 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 →
20252.90.006.3
20262.60.006.0
20272.40.005.8
20282.10.005.5
20291.80.005.2

Savannah Sparrow Survey Routes in Michigan

Routes recording Savannah 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 →
Pickford6320241973
Tyre5019961967
Hamburg2120011981
North Branch2019991974
Hubbard Lake1619961973
St Charles1520101967
Juniata1420241966
Lapeer1420242000
Ontonagon1320191967
Owendale1320171987
Big Rapids919901967
Cathro920161967
Pettysville919791969
Deckerville920241978
Herron920162011
Bergland819901982
Maple Rapids820231987
Bootjack720231967
Riggsville720191967
Lake City620221970
Ola620241974
Adrian620181966
Cedar Run619991999
Walloon Lake 2620182005
Coopersville520241979

Savannah Sparrow Population Trend in Other States

alaskaarizonacaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-dakotatennesseeutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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