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

Great Horned Owl In Eastern Tallgrass Prairie

All regionsEastern Tallgrass PrairieGeneralists

Great Horned Owl in Eastern Tallgrass Prairie has declined: down 37% on the route-weighted index since 1968.

-37%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 →
220Routes 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 →

No notable trend signals for Great Horned Owl in Eastern Tallgrass Prairie. See the full index history below.

Forecast

If the recent trend holds, Great Horned Owl in Eastern Tallgrass Prairie is projected to rise about 38% by 2029 — from 0.11 in 2024 to a central estimate of 0.15 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±88.1%, with 100% of held-out values landing inside the 95% band.

+38%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 →
0.15Projected 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 →
0.00–0.3495% 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 →
±88.1%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, Great Horned Owl in Eastern Tallgrass Prairie is projected to rise about 38% by 2029 — from 0.11 in 2024 to a central estimate of 0.15 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±88.1%, 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 →
20250.160.000.35
20260.160.000.35
20270.160.000.35
20280.150.000.35
20290.150.000.34

Routes In Eastern Tallgrass Prairie

Routes recording Great Horned Owl 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 →
HumboldtILLINOIS52019
MiddletownINDIANA42021
MadisonMISSOURI41998
Mill CreekILLINOIS32023
MelroseIOWA32009
MoreheadKANSAS32019
Trading PostKANSAS32023
FrazierMISSOURI32024
BolckowMISSOURI31988
DunlapOHIO31987
XeniaOHIO31995
ComptonILLINOIS22006
StreatorILLINOIS21985
NewarkILLINOIS22021
WilliamsfldILLINOIS21992
MilfordILLINOIS22001
ClarksdaleILLINOIS22014
JanesvilleILLINOIS21981
JamestownILLINOIS21996
Mt VernonILLINOIS21998
Lake SummersetILLINOIS22011
WaynesvilleILLINOIS22012
W LafayetteINDIANA22022
ThorntownINDIANA22016
NeolaIOWA22006

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