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

Field Sparrow Population Trend in Alabama

All statesForest birds

Field Sparrow in Alabama has collapsed: down 76% on the route-weighted index since 1968.

-76%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 →
94Routes 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 AlabamaNotable 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 collapsed in Alabama: down 76% on the route-weighted index since 1968.

Field Sparrow Population Forecast in Alabama

If the recent trend holds, Field Sparrow in Alabama is projected to fall about 58% by 2030 — from 3.3 in 2025 to a central estimate of 1.4 (95% range 0.00–5.3). A 5-year backtest shows a typical error of ±62.3%, with 100% of held-out values landing inside the 95% band.

-58%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 →
1.4Projected 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 →
0.00–5.395% 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 →
±62.3%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, Field Sparrow in Alabama is projected to fall about 58% by 2030 — from 3.3 in 2025 to a central estimate of 1.4 (95% range 0.00–5.3). A 5-year backtest shows a typical error of ±62.3%, with 100% 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 →
20261.80.005.8
20271.70.005.7
20281.60.005.6
20291.50.005.5
20301.40.005.3

Field Sparrow Survey Routes in Alabama

Routes recording Field Sparrow in Alabama.
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 →
Wheeler Dam1820251993
Stevenson1820241996
Swaim1720251966
Elamville1720251984
Lakeview1720251999
Hillsboro1619941966
Woodville1520241994
Nixburg 21420252000
Liberty City1320111979
Carter Grove1320232002
Talladega1220251996
Dearmanville1119831966
Elkmont1020251990
Eufaula1020241998
Brundidge920211966
Newton820241969
Dawson719981966
Summitt619811966
Mt Olive620251966
Cottonton620251966
Childersburg619991987
Borden Sprng519981993
Calebee520251994
Brooksville520251984
Valhermoso Spg 2520142014

Field Sparrow Population Trend in Other States

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

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.