BirdAnalyst
Species · BCR 22 · BBS 2025 Release · 1966–2024

Horned Lark In Eastern Tallgrass Prairie

All regionsEastern Tallgrass PrairieGrassland birds

Horned Lark in Eastern Tallgrass Prairie has fallen sharply: down 56% on the route-weighted index since 1968.

-56%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 →
270Routes 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 →
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 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 56% on the route-weighted index since 1968.

Forecast

If the recent trend holds, Horned Lark in Eastern Tallgrass Prairie is projected to rise about 16% by 2029 — from 9.1 in 2024 to a central estimate of 10 (95% range 2.6–18). A 5-year backtest shows a typical error of ±51.1%, with 100% of held-out values landing inside the 95% band.

+16%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 →
10Projected 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 →
2.6–1895% 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 →
±51.1%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 16% by 2029 — from 9.1 in 2024 to a central estimate of 10 (95% range 2.6–18). A 5-year backtest shows a typical error of ±51.1%, with 100% of held-out values landing inside the 95% band.19662029
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 →
2025113.619
2026113.419
2027113.119
2028112.919
2029102.618

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 →
W CarrolltonOHIO762015
MelroseILLINOIS691999
MarshallILLINOIS592024
BradburyILLINOIS552024
SextonINDIANA512024
Cedar ValleyIOWA471997
WarrenMISSOURI461984
BloomvilleOHIO462024
AldenILLINOIS352023
AndersonINDIANA342024
StetMISSOURI321995
BeaucoupILLINOIS312024
NorborneMISSOURI312023
BotkinsOHIO312019
TiptonINDIANA301992
JamestownINDIANA302024
MartinsvilleILLINOIS292024
BrookvilleINDIANA292024
FairdaleILLINOIS282024
KalidaOHIO282019
StillwellILLINOIS272023
KunkleOHIO272024
TroyOHIO261996
MonticelloILLINOIS252024
W LafayetteINDIANA252024

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