BirdAnalyst
Species · BCR 21 · BBS 2025 Release · 1966–2024

Northern Harrier In Oaks and Prairies

All regionsOaks and PrairiesGeneralists

Northern Harrier in Oaks and Prairies has held roughly steady: down 8% on the route-weighted index since 1969.

-8%Since 1969TrendPercent 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 →
18Routes 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 →
24YearsYears 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 Northern Harrier in Oaks and Prairies. See the full index history below.

Forecast

If the recent trend holds, Northern Harrier in Oaks and Prairies is projected to fall about 40% by 2019 — from 0.06 in 2014 to a central estimate of 0.04 (95% range 0.00–0.12). A 5-year backtest shows a typical error of ±61.8%, with 80% of held-out values landing inside the 95% band.

-40%Change by 2019TrendPercent 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 →
0.04Projected 2019 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.1295% 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 →
±61.8%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 Oaks and Prairies is projected to fall about 40% by 2019 — from 0.06 in 2014 to a central estimate of 0.04 (95% range 0.00–0.12). A 5-year backtest shows a typical error of ±61.8%, with 80% of held-out values landing inside the 95% band.19672019
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 →
20150.040.000.12
20160.040.000.12
20170.040.000.12
20180.040.000.12
20190.040.000.12

Routes In Oaks and Prairies

Routes recording Northern Harrier in Oaks and Prairies.
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 →
BeggsOKLAHOMA22012
DuncanOKLAHOMA22006
Peach CreekTEXAS21991
CottonwoodTEXAS21998
Mill CreekOKLAHOMA11969
LocoOKLAHOMA11976
NobleOKLAHOMA11975
SkiatookOKLAHOMA11998
LockhartTEXAS11986
Lone OakTEXAS11999
GauseTEXAS11985
KosseTEXAS12014
WeatherfordTEXAS11974
AlbanyTEXAS11969
Miller GroveTEXAS12014
DikeTEXAS11995
OlneyTEXAS11985
MegargelTEXAS12014

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