BirdAnalyst
Species · BCR 10 · BBS 2025 Release · 1966–2024

Great Horned Owl In Northern Rockies

All regionsNorthern RockiesGeneralists

Great Horned Owl in Northern Rockies has fallen sharply: down 72% on the route-weighted index since 1970.

-72%Since 1970TrendPercent 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 →
129Routes 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 →
56YearsYears 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 →

Great Horned Owl has fallen sharply in Northern Rockies: down 71% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Great Horned Owl in Northern Rockies is projected to fall about 75% by 2029 — from 0.12 in 2024 to a central estimate of 0.03 (95% range 0.00–0.18). A 5-year backtest shows a typical error of ±60.3%, with 100% of held-out values landing inside the 95% band.

-75%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 →
0.03Projected 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 →
0.00–0.1895% 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 →
±60.3%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 Northern Rockies is projected to fall about 75% by 2029 — from 0.12 in 2024 to a central estimate of 0.03 (95% range 0.00–0.18). A 5-year backtest shows a typical error of ±60.3%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20250.050.000.20
20260.040.000.20
20270.040.000.19
20280.030.000.19
20290.030.000.18

Routes In Northern Rockies

Routes recording Great Horned Owl in Northern Rockies.
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 →
RandolphUTAH42024
LaurelMONTANA32011
Clyde ParkMONTANA32018
Clover CreekOREGON31989
Summit PrOREGON32010
WorlandWYOMING32012
HarmonyWYOMING32017
Great DivideCOLORADO22024
NaplesIDAHO22024
AlturasIDAHO21969
St MaryMONTANA21992
EllistonMONTANA22006
Cramer CreekMONTANA22006
WickiupOREGON22015
BridgeportOREGON22007
Mount VernonOREGON22022
Silver CreekOREGON22024
Howard Mdws.OREGON21999
BarnhouseOREGON22012
MonumentOREGON22008
MidvaleWYOMING22022
MckinnonWYOMING21980
Bald MtnWYOMING22002
SeedskadeeWYOMING22016
Browns ParkCOLORADO11995

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