Species · Pennsylvania · BBS 2025 Release · 1966–2024

Northern Harrier Population Trend in Pennsylvania

Northern Harrier in Pennsylvania has declined: down 29% on the route-weighted index since 1971.

-29%Since 1971
41Routes In State
40Years

Notable Northern Harrier Trends in Pennsylvania

No notable trend signals for Northern Harrier in Pennsylvania. See the full index history below.

Northern Harrier Population Forecast in Pennsylvania

If the recent trend holds, Northern Harrier in Pennsylvania is projected to stay roughly flat through 2028, near 0.02 (95% range 0.00–0.05). A 5-year backtest shows a typical error of ±115.8%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2028
0.02Projected 2028 index
0.000.0595% range
±115.8%Backtest error
19662028
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected index95% low95% high
20240.020.000.05
20250.020.000.05
20260.020.000.05
20270.020.000.05
20280.020.000.05

Northern Harrier Survey Routes in Pennsylvania

Routes recording Northern Harrier in Pennsylvania.
Shelocta220172017
Ryde219921992
Shrewsbury219961996
Slippery Rk119761970
Espyville119711971
Harmonsburg119951975
Ferris Crnrs119891989
Ellenton120041999
Teepleville119921966
Sigel119951995
N Washington119961996
Pottersdale119921992
Betula119871987
Sproul Sf-B120232022
Ridgway120052005
Rasselas120212021
Arnot120231983
Little Marsh120131988
Rosecrans120002000
Austinville120121991
Rush119901990
Bow Bridge120082002
Waller120142014
Millville120082007
Hop Bottom119701970

Northern Harrier Population Trend in Other States

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