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

White-crowned Sparrow Population Trend in Montana

All statesGeneralists

White-crowned Sparrow in Montana has risen sharply: up 70% on the route-weighted index since 1970.

+70%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 →
40Routes 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 →
56YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable White-crowned Sparrow Trends in MontanaNotable 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 risen sharply in Montana: up 70% on the route-weighted index since 1970.

White-crowned Sparrow Population Forecast in Montana

If the recent trend holds, White-crowned Sparrow in Montana is projected to fall about 21% by 2029 — from 3.2 in 2024 to a central estimate of 2.5 (95% range 0.95–4.1). A 5-year backtest shows a typical error of ±21.5%, with 100% of held-out values landing inside the 95% band.

-21%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 →
2.5Projected 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 →
0.95–4.195% 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 →
±21.5%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 Montana is projected to fall about 21% by 2029 — from 3.2 in 2024 to a central estimate of 2.5 (95% range 0.95–4.1). A 5-year backtest shows a typical error of ±21.5%, with 100% 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 →
20252.50.914.1
20262.50.924.1
20272.50.934.1
20282.50.944.1
20292.50.954.1

White-crowned Sparrow Survey Routes in Montana

Routes recording White-crowned Sparrow in Montana.
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 →
Red Rock6520241973
Hebgen Lake3720242017
Chestnut3320241968
Beaverhead3320241973
East Glacier Park1920242015
Logan Pass1520241980
St. Mary 21520242009
Sula1220241977
Maynard Coulee1220242017
Skalkaho1219981992
St Mary1020081971
Heart Butte820242015
Skalkho-Rye620221999
Brunzell Slough620242016
Pryor Mtn.420241995
Elliston420241968
Painted Rock419981992
Wise River420241993
Lima420241994
St Regis319781978
Cleveland220011979
Redstone219701970
Arlee220171973
Woodman220151980
Powderville219681968

White-crowned Sparrow Population Trend in Other States

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