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

Field Sparrow Population Trend in Michigan

All statesGeneralists

Field Sparrow in Michigan has fallen sharply: down 67% on the route-weighted index since 1968.

-67%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 →
91Routes 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 Field 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 →

Field Sparrow has fallen sharply in Michigan: down 67% on the route-weighted index since 1968.

Field Sparrow Population Forecast in Michigan

If the recent trend holds, Field Sparrow in Michigan is projected to fall about 60% by 2029 — from 3.0 in 2024 to a central estimate of 1.2 (95% range 0.00–3.4). A 5-year backtest shows a typical error of ±51.1%, with 80% of held-out values landing inside the 95% band.

-60%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 →
1.2Projected 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 →
0.00–3.495% 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 →
±51.1%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, Field Sparrow in Michigan is projected to fall about 60% by 2029 — from 3.0 in 2024 to a central estimate of 1.2 (95% range 0.00–3.4). A 5-year backtest shows a typical error of ±51.1%, with 80% 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 →
20251.70.003.9
20261.60.003.8
20271.40.003.6
20281.30.003.5
20291.20.003.4

Field Sparrow Survey Routes in Michigan

Routes recording Field 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 →
Drayton Plns3519871973
Howardsville1420241969
Almena1220151993
Remus1120241974
Barry S.G.A.1120121995
Galesburg920241966
Fowlerville920191974
Waldenburg920001968
Harrietta920241990
Monterey820241978
Sand Lake820241980
Juniata820241966
Hamburg820011981
New Buffalo820141992
Lawrence720241969
Hubbard Lake719881986
North Branch719981974
Adair719951978
Cohoctah720242021
Hungerford720241991
Hamburg 2720242004
Bear Lake620241967
Mottville620241967
Maple Rapids620231987
Homer620241975

Field Sparrow Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming

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