BirdAnalyst
Species · Nevada · BBS 2026 Release · 1966–2025

Northern Harrier Population Trend in Nevada

All statesBirds of prey

Northern Harrier in Nevada has surged: up 179% on the route-weighted index since 1970.

+179%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 →
39Routes 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 →
47YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Northern Harrier 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 →

Northern Harrier has surged in Nevada: up 179% on the route-weighted index since 1970.

Northern Harrier Population Forecast in Nevada

If the recent trend holds, Northern Harrier in Nevada is projected to rise about 131% by 2030 — from 0.38 in 2025 to a central estimate of 0.88 (95% range 0.27–1.5). A 5-year backtest shows a typical error of ±132.6%, with 40% of held-out values landing inside the 95% band.

+131%Change by 2030TrendPercent 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 →
0.88Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.27–1.595% 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 →
±132.6%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, Northern Harrier in Nevada is projected to rise about 131% by 2030 — from 0.38 in 2025 to a central estimate of 0.88 (95% range 0.27–1.5). A 5-year backtest shows a typical error of ±132.6%, with 40% of held-out values landing inside the 95% band.19682030
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 →
20260.840.231.4
20270.850.241.5
20280.860.251.5
20290.870.261.5
20300.880.271.5

Northern Harrier Survey Routes in Nevada

Routes recording Northern Harrier 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 →
Hiko920161968
Ruby Valley 2720242007
Dinner Sta319931992
Toiyabe Nf320241996
Charleston Reservoir320242024
Ash Meadows320241993
Midas220251974
Fish Creek220191997
Sutcliffe219711969
Willis220241997
Minerva220181988
Jarbidge220061997
Sheldon Nwr220191997
Austin220182008
Virgin Creek220181995
Chimney Res.220232005
Fallon220241998
Piute Mdws120252025
Ranchogrande120241997
Sand Pass120251987
Rye Patch119871970
Cortez120252016
Walker Can120221972
Mizpah120141994
Comins Lake120162012

Northern Harrier Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradodelawaregeorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamissourimontananebraskanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.