BirdAnalyst
Species · BCR 2 · BBS 2025 Release · 1966–2024

White-crowned Sparrow In BCR 2

All regionsBCR 2Generalists

White-crowned Sparrow in BCR 2 has surged: up 105% on the route-weighted index since 1987.

+105%Since 1987TrendPercent 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 →
20Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
34YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 →

White-crowned Sparrow has surged in BCR 2: up 105% on the route-weighted index since 1987.

White-crowned Sparrow In BCR 2 Population Forecast

If the recent trend holds, White-crowned Sparrow in BCR 2 is projected to rise about 106% by 2029 — from 14 in 2024 to a central estimate of 29 (95% range 16–41). A 5-year backtest shows a typical error of ±73.4%, with 20% of held-out values landing inside the 95% band.

+106%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 →
29Projected 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 →
16–4195% 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 →
±73.4%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, White-crowned Sparrow in BCR 2 is projected to rise about 106% by 2029 — from 14 in 2024 to a central estimate of 29 (95% range 16–41). A 5-year backtest shows a typical error of ±73.4%, with 20% of held-out values landing inside the 95% band.19842029
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 →
2025271540
2026281540
2027281640
2028281641
2029291641

Routes In BCR 2

Routes recording White-crowned Sparrow in BCR 2.
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 →
King SalmonALASKA482024
St. Mary'SALASKA382014
Katmai N.P.ALASKA362022
KotzebueALASKA342024
DillinghamALASKA282019
Dillingham (Short)ALASKA241984
Kotzebue (Short)ALASKA191994
Selawik (Short)ALASKA161987
NomeALASKA152023
Salmon LakeALASKA142024
Kugarak (Short)ALASKA121987
Cape NomeALASKA102024
TellerALASKA92024
Goodnews BayALASKA92004
CouncilALASKA72024
Cold BayALASKA32024
Gweek RiverALASKA32002
TupuknukALASKA31995
Kanektok RivALASKA22004
Togiak RiverALASKA12005

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