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

Field Sparrow Population Trend in Tennessee

All statesGeneralists

Field Sparrow in Tennessee has fallen sharply: down 56% on the route-weighted index since 1968.

-56%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 →
54Routes 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 TennesseeNotable 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 Tennessee: down 56% on the route-weighted index since 1968.

Field Sparrow Population Forecast in Tennessee

If the recent trend holds, Field Sparrow in Tennessee is projected to fall about 10% by 2029 — from 11 in 2024 to a central estimate of 9.6 (95% range 4.4–15). A 5-year backtest shows a typical error of ±8.6%, with 100% of held-out values landing inside the 95% band.

-10%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 →
9.6Projected 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 →
4.4–1595% 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 →
±8.6%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 Tennessee is projected to fall about 10% by 2029 — from 11 in 2024 to a central estimate of 9.6 (95% range 4.4–15). A 5-year backtest shows a typical error of ±8.6%, 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 →
20259.94.715
20269.94.715
20279.84.615
20289.74.515
20299.64.415

Field Sparrow Survey Routes in Tennessee

Routes recording Field Sparrow in Tennessee.
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 →
Corryton Rd4120191966
Mansfield3520241966
Petersburg2120191966
Humboldt2020241966
Peytonsville2020241966
Collinwood1920241966
Glen1920241966
Mt Olive1920241966
Jones Gap1920191982
Tibbs1820241966
Tullahoma1820151967
Campbellsville1720191966
Brownsville1620241966
White House1620191966
Bradyville1620211966
Union Hill1620241967
Pawpaw1520121966
Big Sandy1520241966
Allens Brdge1520231966
Wrigley1420221966
Lovell1420191966
Jefferson Cty1320111966
Indian Mound 21120232004
Sweetlips920231966
Pond Creek920241966

Field Sparrow Population Trend in Other States

alabamaarkansascoloradoconnecticutdelawarefloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatexasvermontvirginiawest-virginiawisconsinwyoming

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