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Species · BCR 4 · BBS 2025 Release · 1966–2024

Horned Lark In BCR 4

All regionsBCR 4Grassland birds

Horned Lark in BCR 4 has collapsed: down 77% on the route-weighted index since 1986.

-77%Since 1986TrendPercent 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 →
5Routes 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 →
23YearsYears 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 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 →

Horned Lark has collapsed in BCR 4: down 77% on the route-weighted index since 1986.

Horned Lark In BCR 4 Population Forecast

If the recent trend holds, Horned Lark in BCR 4 is projected to stay roughly flat through 2028, near 0.02 (95% range 0.00–0.27). A 5-year backtest shows a typical error of ±170.2%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2028TrendPercent 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 →
0.02Projected 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.2795% 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 →
±170.2%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, Horned Lark in BCR 4 is projected to stay roughly flat through 2028, near 0.02 (95% range 0.00–0.27). A 5-year backtest shows a typical error of ±170.2%, with 100% of held-out values landing inside the 95% band.19822028
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 →
20240.030.000.28
20250.030.000.28
20260.020.000.28
20270.020.000.27
20280.020.000.27

Routes In BCR 4

Routes recording Horned Lark in BCR 4.
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 →
Ft. RichrdsnALASKA261998
MaclarenALASKA12007
MonahanALASKA11992
ToklatALASKA12021
SavageALASKA12023

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