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

Fox Sparrow Population Trend in Nevada

All statesForest birds

Fox Sparrow in Nevada has declined: down 33% on the route-weighted index since 1995.

-33%Since 1995TrendPercent 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 →
12Routes 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 →
26YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Fox Sparrow Trends in NevadaNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Fox Sparrow in Nevada. See the full index history below.

Fox Sparrow Population Forecast in Nevada

If the recent trend holds, Fox Sparrow in Nevada is projected to fall about 48% by 2030 — from 0.10 in 2025 to a central estimate of 0.05 (95% range 0.00–0.50). A 5-year backtest shows a typical error of ±109.4%, with 100% of held-out values landing inside the 95% band.

-48%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 →
0.05Projected 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 →
0.00–0.5095% 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 →
±109.4%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, Fox Sparrow in Nevada is projected to fall about 48% by 2030 — from 0.10 in 2025 to a central estimate of 0.05 (95% range 0.00–0.50). A 5-year backtest shows a typical error of ±109.4%, with 100% of held-out values landing inside the 95% band.19932030
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 →
20260.090.000.54
20270.080.000.53
20280.070.000.52
20290.060.000.51
20300.050.000.50

Fox Sparrow Survey Routes in Nevada

Routes recording Fox Sparrow in Nevada.
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 →
Hawthorne1220011997
Ruby Valley720011999
Austin620182016
Humboldt Nf420191993
Chimney Res.220152014
Humboldt Nf 2220252025
Jarbidge120141997
Comins Lake120062006
Fish Creek120192008
Charleston Reservoir120242024
Toiyabe Nf120172017
Willis120091995

Fox Sparrow Population Trend in Other States

alaskacaliforniacoloradoidahomainemontanaoregonutahwashingtonwyoming

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