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Species · Nebraska · BBS 2026 Release · 1966–2025

Chestnut-collared Longspur Population Trend in Nebraska

All statesGrassland birds

Chestnut-collared Longspur in Nebraska has collapsed: down 95% on the route-weighted index since 1969.

-95%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 →
7Routes 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 →
45YearsYears 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 NebraskaNotable 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 Nebraska: down 94% on the route-weighted index since 1969.

Chestnut-collared Longspur Population Forecast in Nebraska

If the recent trend holds, Chestnut-collared Longspur in Nebraska is projected to fall about 100% by 2030 — from 0.18 in 2025 to a central estimate of 0.00 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±585.6%, 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 →
0.00–1.195% 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 →
±585.6%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 Nebraska is projected to fall about 100% by 2030 — from 0.18 in 2025 to a central estimate of 0.00 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±585.6%, 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 →
20260.000.001.1
20270.000.001.1
20280.000.001.1
20290.000.001.1
20300.000.001.1

Chestnut-collared Longspur Survey Routes in Nebraska

Routes recording Chestnut-collared Longspur in Nebraska.
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 →
Agate1220011967
Kimball820251975
Eagle Creek319771970
Gordon220251978
Agate 2120252002
Oglala Nat. Grass.120082002
Johnstown119701970

Chestnut-collared Longspur Population Trend in Other States

coloradominnesotamontananorth-dakotasouth-dakotawyoming

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