BirdAnalyst
Species · Michigan · BBS 2026 Release · 1966–2025

Field Sparrow Population Trend in Michigan

All statesForest birds

Field Sparrow in Michigan has fallen sharply: down 68% on the route-weighted index since 1968.

-68%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 →
59YearsYears 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 68% 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 63% by 2030 — from 3.1 in 2025 to a central estimate of 1.2 (95% range 0.00–3.4). A 5-year backtest shows a typical error of ±53%, with 80% of held-out values landing inside the 95% band.

-63%Change by 2030TrendPercent 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 2030 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 →
±53%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 63% by 2030 — from 3.1 in 2025 to a central estimate of 1.2 (95% range 0.00–3.4). A 5-year backtest shows a typical error of ±53%, with 80% of held-out values landing inside the 95% band.19662030
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 →
20261.70.003.9
20271.50.003.8
20281.40.003.6
20291.30.003.5
20301.20.003.4

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
Galesburg1720251966
Scottville1320251968
Howardsville1320251969
Remus1220251974
Almena1220151993
Nashville1120251968
Harrietta1120251990
Barry S.G.A.1120121995
Fowlerville920191974
Waldenburg920001968
Monterey820251978
Sand Lake820251980
Juniata820241966
Hamburg820011981
New Buffalo820141992
Hubbard Lake719881986
North Branch719981974
Adair719951978
Homer620241975
Hungerford620251991
Lawrence520251969
Red Oak520221985
Prattville520211967
Cohoctah520252021

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 2026-08-14.