Species · Michigan · BBS 2025 Release · 1966–2024

Northern Harrier Population Trend in Michigan

Northern Harrier in Michigan has collapsed: down 83% on the route-weighted index since 1968.

-83%Since 1968
61Routes In State
57Years

Notable Northern Harrier Trends in Michigan

long arc declinecomputed index

Northern Harrier has collapsed in Michigan: down 83% on the route-weighted index since 1968.

Northern Harrier Population Forecast in Michigan

If the recent trend holds, Northern Harrier in Michigan is projected to stay roughly flat through 2029, near 0.06 (95% range 0.00–0.19). A 5-year backtest shows a typical error of ±87.7%, with 100% of held-out values landing inside the 95% band.

-8%Change by 2029
0.06Projected 2029 index
0.000.1995% range
±87.7%Backtest error
19662029
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
20250.070.000.20
20260.070.000.19
20270.060.000.19
20280.060.000.19
20290.060.000.19

Northern Harrier Survey Routes in Michigan

Routes recording Northern Harrier in Michigan.
Crystal Fls219921982
Skeels219891967
No Bradley219941970
Beaver Lake219701968
Hubbard Lake219931974
Owendale219921979
S Lyons219701966
Seney Nwr220182008
Ontonagon119671967
Hungerford119951995
Bootjack120091968
Ned Lake119881986
Chippewa Lk.120022002
Gibbs City120061999
Maple Grove120241970
Ishpeming119811981
Brocky Lake120182018
Wilson120091968
Cunard119941987
Shingleton120051967
Walloon Lake 2120082008
Isabella120041972
Bear Lake120121988
Scottville119761976
Hamburg 2120142014

Northern Harrier Population Trend in Other States

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