BirdAnalyst
Species · North Dakota · BBS 2026 Release · 1966–2025

Chestnut-collared Longspur Population Trend in North Dakota

All statesGrassland birds

Chestnut-collared Longspur in North Dakota has collapsed: down 83% on the route-weighted index since 1969.

-83%Since 1969TrendPercent 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 →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Chestnut-collared Longspur Trends in North DakotaNotable 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 declinecomputed 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 →

Chestnut-collared Longspur has collapsed in North Dakota: down 83% on the route-weighted index since 1969.

Chestnut-collared Longspur Population Forecast in North Dakota

If the recent trend holds, Chestnut-collared Longspur in North Dakota is projected to fall about 100% by 2030 — from 6.1 in 2025 to a central estimate of 0.00 (95% range 0.00–10). A 5-year backtest shows a typical error of ±116.7%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–1095% 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 →
±116.7%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, Chestnut-collared Longspur in North Dakota is projected to fall about 100% by 2030 — from 6.1 in 2025 to a central estimate of 0.00 (95% range 0.00–10). A 5-year backtest shows a typical error of ±116.7%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20260.000.0010
20270.000.0010
20280.000.0010
20290.000.0010
20300.000.0010

Chestnut-collared Longspur Survey Routes in North Dakota

Routes recording Chestnut-collared Longspur in North Dakota.
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 →
Cedar Creek6920221968
Sydney2919831968
Dunn Center2620251968
Zap2420241967
Carson2020251988
Gorham1920251968
Ft Yates1620041968
Dickinson1320251968
Wild Rose1320251982
Lark1219821968
Bowman1220251967
Danzig 21120252019
Glen Ullin920251982
Denbigh820251968
Horsehead Lk720251980
Bentley720241988
Solen720252005
Sheyenne Lk620251980
Cooperstown519941970
Stanley420251967
Powers Lake420251980
Braddock420231988
Buchanan320141967
Niles319891989
Golva320251980

Chestnut-collared Longspur Population Trend in Other States

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