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

Song Sparrow Population Trend in Idaho

All statesForest birds

Song Sparrow in Idaho has surged: up 94% on the route-weighted index since 1970.

+94%Since 1970TrendPercent 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 →
61Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Song Sparrow Trends in IdahoNotable 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 increasecomputed 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 →

Song Sparrow has surged in Idaho: up 94% on the route-weighted index since 1970.

Song Sparrow Population Forecast in Idaho

If the recent trend holds, Song Sparrow in Idaho is projected to fall about 19% by 2030 — from 9.1 in 2025 to a central estimate of 7.4 (95% range 3.7–11). A 5-year backtest shows a typical error of ±13.3%, with 100% of held-out values landing inside the 95% band.

-19%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 →
7.4Projected 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 →
3.7–1195% 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 →
±13.3%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, Song Sparrow in Idaho is projected to fall about 19% by 2030 — from 9.1 in 2025 to a central estimate of 7.4 (95% range 3.7–11). A 5-year backtest shows a typical error of ±13.3%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20267.33.511
20277.33.611
20287.33.611
20297.43.611
20307.43.711

Song Sparrow Survey Routes in Idaho

Routes recording Song Sparrow in Idaho.
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 →
Centerville5720251972
Challis5020251975
Naples3320251972
Nezperce2620121968
Cabarton2520241985
Magic Mtn2420251987
Gifford2320171971
Sunbeam2320251994
Pierce2220071990
Golden2020161987
Almo1720251988
Rochat Divde1620251993
Baker1520241974
N Fork Cda R1520191993
Featherville1420251989
Joel1320241989
Coolin1020251986
Crane Creek1020191988
Cobalt920251989
Bates820231988
Avery720251979
Cape Horn720251972
Pocatello720191979
Marble Creek720251988
Picabo720251988

Song Sparrow Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawaregeorgiaillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseeutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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