Migration Statistics
Season Statistics
Each fall, Hawk Ridge averaged 76,000 migrating raptors from 1991-2013 and, using a different sampling procedure, averaged 39,000 raptors from 1972-1990.
In addition to the common raptors, listed below, other raptor species recorded include:
- Black Vulture: one record (2000)
- Mississippi Kite: 1-3 observed in eleven years (1991-2013)
- Red-shouldered Hawk: 1-8 observed in 21 years (1990-2013), peak timing in Oct
- Swainson’s Hawk: 2-10 birds observed most years, peak timing in Sept
- Gyrfalcon: one bird observed in eleven years (1972-2013)
- Prairie Falcon: three records (1979, 1991, 1993)
Species Trend Graphs from the Raptor Population Index HERE
Statistics of Common Raptors
Image Credits: Brent Alan Kauth
Turkey Vulture
Peak Migration: late Sep - early Oct
Record Daily High: 799 on 29 Sep 1996
Record Seasonal High: 1952 in 1996
Bald Eagle
Peak Migration: 1st peak in Sept, 2nd peak in Oct
Record Daily High: 743 on 22 Nov 1994
Record Seasonal High: 6099 in 2017
Northern Harrier
Peak Migration: late Aug- early Oct
Record Daily High: 172 Sept 17, 1994; Sept 15, 1999
Record Seasonal High: 1,100 in 1999
Sharp-shinned Hawk (Accipiter striatus)
Peak Migration: mid Sept - early Oct
Record Daily High: 2515 on Sept 24, 2017
Record Seasonal High: 22,602 in 2016
Cooper’s Hawk (Accipiter cooperii)
Peak Migration: mid Sept – early Oct
Record Daily High: 43 on 15 Sep 1999
Record Seasonal High: 319 in 1993
Northern Goshawk (Accipiter gentilis)
Peak Migration: mid Oct – early Nov
Record Daily High: 1068 on Oct 15, 1982
Record Seasonal High: 4963 in 1972
Broad-winged Hawk
Peak Migration: 10 Sep - 25 Sep
Record Daily High: 101,698 on Sept 15, 2003
Record Seasonal High: 160,703 in 2003
Red-tailed Hawk
Peak Migration: Early Oct - early Nov
Record Daily High: 3,988 on Oct. 24, 1994
Record Seasonal High: 15,358 in 1994
Rough-legged Hawk
Peak Migration: Mid Oct – Early Nov
Record Daily High: 322 on Oct 25, 2017
Record Seasonal High: 1123 in 2017
Golden Eagle
Peak Migration: late Oct – Nov
Record Daily High: 57 on Nov 12, 2012
Record Seasonal High: 223 in 2009
Great Horned Owl
Earliest Date: Oct 15
Latest Date: Dec 8
Peak Migration: after Nov 15
Barred Owl
Earliest Date: Sep 30
Latest Date: Dec 1
Peak Migration: 15 - 31 Oct
Long-eared Owl
Earliest Date: Sep 4
Latest Date: Nov 19
Peak Migration: 15 - 31 Oct
Short-eared Owl
Earliest Date: 29 Sept
Latest Date: 31 Oct
Peak Migration: mid-Oct
Boreal Owl
Earliest Date: Oct 11
Latest Date: Nov 19
Peak Migration: 20 Oct - 5 Nov
Northern Saw-whet Owl
Earliest Date: Aug 17
Latest Date: Nov 16
Peak Migration: 1 – 31 Oct
American Kestrel
Peak Migration: late Aug - early Oct
Record Daily High: 744 on 9 Sep 2002
Record Seasonal High: 3,637 in 2002
Merlin
Peak Migration: Sept –Oct
Record Daily High: 73 on 9 Oct 1997
Record Seasonal High: 399 in 2016
Peregrine Falcon
Peak Migration: mid Sept – early Oct
Record Daily High: 33 on Sept 20, 2013
Record Seasonal High: 182 in 2016