BirdAnalyst
Species · BCR 13 · BBS 2025 Release · 1966–2024

Great Horned Owl In Lower Great Lakes / St. Lawrence Plain

All regionsLower Great Lakes / St. Lawrence PlainGeneralists

Great Horned Owl in Lower Great Lakes / St. Lawrence Plain has held roughly steady: down 1% on the route-weighted index since 1968.

-1%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 →
56Routes 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 →
52YearsYears 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 Lower Great Lakes / St. Lawrence Plain. See the full index history below.

Forecast

If the recent trend holds, Great Horned Owl in Lower Great Lakes / St. Lawrence Plain is projected to stay roughly flat through 2029, near 0.03 (95% range 0.00–0.13). A 5-year backtest shows a typical error of ±50.9%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.00–0.1395% 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 →
±50.9%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, Great Horned Owl in Lower Great Lakes / St. Lawrence Plain is projected to stay roughly flat through 2029, near 0.03 (95% range 0.00–0.13). A 5-year backtest shows a typical error of ±50.9%, 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 →
20250.030.000.14
20260.030.000.14
20270.030.000.14
20280.030.000.14
20290.030.000.13

Routes In Lower Great Lakes / St. Lawrence Plain

Routes recording Great Horned Owl in Lower Great Lakes / St. Lawrence Plain.
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 →
Valley CityOHIO32007
RomulusNEW-YORK21986
MendonNEW-YORK21997
HamburgNEW-YORK22024
Cicero CtrNEW-YORK22014
PulaskiNEW-YORK21989
New SomersetOHIO21979
HebronOHIO21998
Ferris CrnrsPENNSYLVANIA21998
North PownalVERMONT21991
HighlandNEW-YORK12006
W ShokanNEW-YORK11970
CatskillsNEW-YORK11996
GhentNEW-YORK12003
Ballston LkNEW-YORK11970
Oriskany FlsNEW-YORK12023
TrumansburgNEW-YORK11980
OrleansNEW-YORK12009
RushvilleNEW-YORK11971
BranchportNEW-YORK11969
Mt MorrisNEW-YORK11979
CastileNEW-YORK11985
SheridanNEW-YORK11976
Cherry HillNEW-YORK12012
NashvilleNEW-YORK11993

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