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

Fox Sparrow Population Trend in Alaska

All statesGeneralists

Fox Sparrow in Alaska has surged: up 82% on the route-weighted index since 1975.

+82%Since 1975TrendPercent 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 →
128Routes 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 →
48YearsYears 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 AlaskaNotable 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 →

Fox Sparrow has surged in Alaska: up 82% on the route-weighted index since 1975.

Fox Sparrow Population Forecast in Alaska

If the recent trend holds, Fox Sparrow in Alaska is projected to rise about 49% by 2029 — from 16 in 2024 to a central estimate of 24 (95% range 14–35). A 5-year backtest shows a typical error of ±47%, with 80% of held-out values landing inside the 95% band.

+49%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 →
24Projected 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 →
14–3595% 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 →
±47%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 Alaska is projected to rise about 49% by 2029 — from 16 in 2024 to a central estimate of 24 (95% range 14–35). A 5-year backtest shows a typical error of ±47%, with 80% of held-out values landing inside the 95% band.19682029
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 →
2025231334
2026241334
2027241434
2028241434
2029241435

Fox Sparrow Survey Routes in Alaska

Routes recording Fox Sparrow in Alaska.
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 →
Chiniak16820241985
Kodiak 214020241985
Kodiak10719841983
Copper River10220111993
Gweek River7820021994
Thompson Pas7520241983
St. Mary'S6820141993
Nome6320231993
Tupuknuk5219951995
Salmon Lake4920241993
Goose Bay4819821975
Anvik River4620241998
Council4420241993
Dillingham3920191993
Kachemak3620241986
Selawik (Short)3619871986
Monahan3520211983
Toklat3420241982
Cohoe3320232012
Anchor River3220241983
Koyukuk Riv.3220011994
Dillingham (Short)3119841984
Mt. Fairplay3120241993
Delta2820241995
Mud River2720241993

Fox Sparrow Population Trend in Other States

californiacoloradoidahomainemontananevadaoregonutahwashingtonwyoming

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