BirdAnalyst
Species · BCR 22 · BBS 2026 Release · 1966–2025

Horned Lark In Eastern Tallgrass Prairie

All regionsEastern Tallgrass PrairieGrassland birds

Horned Lark in Eastern Tallgrass Prairie has fallen sharply: down 57% on the route-weighted index since 1968.

-57%Since 1968TrendPercent 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 →
272Routes 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 →
59YearsYears 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 fallen sharply in Eastern Tallgrass Prairie: down 57% on the route-weighted index since 1968.

Horned Lark In Eastern Tallgrass Prairie Population Forecast

If the recent trend holds, Horned Lark in Eastern Tallgrass Prairie is projected to rise about 22% by 2030 — from 8.2 in 2025 to a central estimate of 10.0 (95% range 2.2–18). A 5-year backtest shows a typical error of ±48.9%, with 100% of held-out values landing inside the 95% band.

+22%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 →
10.0Projected 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 →
2.2–1895% 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 →
±48.9%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 Eastern Tallgrass Prairie is projected to rise about 22% by 2030 — from 8.2 in 2025 to a central estimate of 10.0 (95% range 2.2–18). A 5-year backtest shows a typical error of ±48.9%, with 100% of held-out values landing inside the 95% band.19662030
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 →
2026113.219
2027112.919
2028102.718
2029102.418
203010.02.218

Routes In Eastern Tallgrass Prairie

Routes recording Horned Lark in Eastern Tallgrass Prairie.
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 →
BrookvilleINDIANA872025
W CarrolltonOHIO762015
MelroseILLINOIS691999
MarshallILLINOIS562025
SextonINDIANA512024
Cedar ValleyIOWA471997
WarrenMISSOURI461984
Witts StationINDIANA412025
JamestownINDIANA392025
W LafayetteINDIANA382025
BloomvilleOHIO362025
KellILLINOIS342025
BradburyILLINOIS322025
StetMISSOURI321995
MartinsvilleILLINOIS312025
NorborneMISSOURI312023
BotkinsOHIO312019
TiptonINDIANA301992
KentonOHIO302025
OlsburgKANSAS292025
MurdockNEBRASKA292025
MonticelloILLINOIS272025
BeaucoupILLINOIS272025
PaysonILLINOIS272025
KunkleOHIO272025

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