BirdAnalyst
Species · Nevada · BBS 2025 Release · 1966–2024

Great Horned Owl Population Trend in Nevada

All statesGeneralists

Great Horned Owl in Nevada has surged: up 109% on the route-weighted index since 1974.

+109%Since 1974TrendPercent 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 →
19Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
33YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Great Horned Owl Trends in NevadaNotable 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 increasecomputed 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 surged in Nevada: up 109% on the route-weighted index since 1974.

Great Horned Owl Population Forecast in Nevada

If the recent trend holds, Great Horned Owl in Nevada is projected to fall about 40% by 2029 — from 0.18 in 2024 to a central estimate of 0.11 (95% range 0.00–0.43). A 5-year backtest shows a typical error of ±44.6%, with 100% of held-out values landing inside the 95% band.

-40%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 →
0.11Projected 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 →
0.00–0.4395% 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 →
±44.6%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 Nevada is projected to fall about 40% by 2029 — from 0.18 in 2024 to a central estimate of 0.11 (95% range 0.00–0.43). A 5-year backtest shows a typical error of ±44.6%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20250.110.000.43
20260.110.000.43
20270.110.000.43
20280.110.000.43
20290.110.000.43

Great Horned Owl Survey Routes in Nevada

Routes recording Great Horned Owl in Nevada.
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 →
Ruby Valley 2220212009
Nelson220242006
Gardnerville 2220152015
Piute Mdws120212021
Midas119991999
Ranchogrande119961992
Sand Pass119941994
Humboldt Nf120152015
Cortez120162016
Walker Can120241969
Mizpah120242024
Meadow Vally119961996
Majors Place119991996
Gardnerville120021995
Dobbin Creek119781978
Jarbidge120062006
Bald Mtn.120011992
Chimney Res.120242013
Fallon120221993

Great Horned Owl Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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