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

Northern Harrier Population Trend in Nevada

All statesGeneralists

Northern Harrier in Nevada has surged: up 187% on the route-weighted index since 1970.

+187%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 →
38Routes 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 →
46YearsYears 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 186% 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 stay roughly flat through 2029, near 0.91 (95% range 0.31–1.5). A 5-year backtest shows a typical error of ±131.1%, with 40% of held-out values landing inside the 95% band.

-2%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 →
0.91Projected 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 →
0.31–1.595% 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 →
±131.1%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, Northern Harrier in Nevada is projected to stay roughly flat through 2029, near 0.91 (95% range 0.31–1.5). A 5-year backtest shows a typical error of ±131.1%, with 40% 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 →
20250.860.261.5
20260.870.281.5
20270.880.291.5
20280.900.301.5
20290.910.311.5

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
Midas820121974
Ruby Valley 2720242007
Dinner Sta319931992
Sand Pass320241987
Toiyabe Nf320241996
Charleston Reservoir320242024
Ash Meadows320241993
Fish Creek220191997
Sutcliffe219711969
Majors Place220191968
Willis220241997
Minerva220181988
Jarbidge220061997
Sheldon Nwr220191997
Austin220182008
Virgin Creek220181995
Bald Mtn.220241992
Chimney Res.220232005
Fallon220241998
Ranchogrande120241997
Rye Patch119871970
Cortez120192016
Walker Can120221972
Mizpah120141994

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 2026-05-22.