Status: Uncommon regular spring and fall migrant west and central, rare casual east. Uncommon regular breeder west, north, and southwest. Uncommon regular winter visitor central and west, rare casual east.
Breeding and migration
Documentation: Specimen: UNSM ZM7687, Stapleton, Logan Co 24 Jan 1935.
Taxonomy: No subspecies are recognized.
As with Swainson’s Hawk, Ferruginous Hawk has a range of color morphs, including dark, intermediate (rufous), and light, but dark and intermediate birds comprise 5% or less of the breeding population in Colorado (Wheeler 2003). There is some evidence that at certain times and locations the proportion of dark birds in Nebraska may be higher than that indicated by Wheeler; Nebraska Prairie Partners, a partnership between Bird Conservancy of the Rockies and the Nebraska Game and Parks Commission, found a concentration of dark morphs in Morrill Co in summer of 2007 (Bart Bly, pers. comm.), and about 10% of Ferruginous Hawks found in the winters 1978-79 and 1979-80 along the central Platte River Valley were “dark-phase” birds (Lingle 1989). Additional records of dark birds, all during winter, include a specimen, UNSM ZM7687, taken at Stapleton, Logan Co 24 Jan 1935, one in Hayes Co 25 Oct 2014, one on 1 Nov 1987 near Keystone, Keith Co (Rosche 1994), one near Kearney 11 Nov 2001, and one of four found on the Lake McConaughy CBC 19 Dec 2005 was a dark bird.
Spring: winter <<<>>> May 12,13,14
Late dates above, albeit none with details, are from areas east of the breeding range, mostly Jefferson, Webster, Clay, Adams, Lancaster, and Polk Cos. According to Palmer (1988), most migration occurs in Mar-Apr, with immature non-breeders following later, as late as Jun. Rosche (1994) lists this species as a spring transient in the west 10 Mar-18 May. Many Nebraska breeders may be resident or short-distance migrants (Bechard and Schmutz 1995).
There is only one documented record in the far east: a light morph juvenile was photographed in Lancaster Co 15 Apr 2018. There are a few additional reports without details; immature Ferruginous Hawks can be difficult to identify. These reports are 4 Mar 1992 Cass Co, 8 Mar 1981 Nemaha Co (Shupe and Collins 1983), 25 Mar 1979 Douglas-Sarpy Cos, an immature 22 Apr 2011 Dakota Co, and a “light adult” in Butler Co 5 May 2006.
Summer: The breeding range in Nebraska is limited to the western third of the state, where densities are highest in the western Panhandle north and south of the North Platte River, although nesting has occurred east to Hooker, Lincoln, Hayes and Dundy Cos (Ducey 1988, Johnsgard 1997). There is also a credible report, albeit with limited details, of nesting in 1979 near Axtell, Phelps Co (NGPC, unpublished data).
Ferruginous Hawk was apparently formerly more widespread, occurring statewide; Bruner et al (1904) stated that it bred in “moderate numbers in the Sandhills, and commonly along the Pine Ridge and about the buttes of western and northwestern Nebraska”. . Subsequently, though, numbers declined, its range was reduced, and, by the 1970s, NGPC considered it a species of “unknown status” (Wingfield 1985). By 1980, the Ferruginous Hawk breeding range was believed to be limited to northwest Nebraska (Johnsgard 1980). Surveys conducted by NGPC (with USFWS in 1983-84) from 1981-88 located 21 nest sites by 1983 and that number reached 30 in 1986 and 1987 (Carlson et al 1983, 1984; Wingfield 1985, 1986, 1987, 1988). Out of 62 eyries identified by NGPC by 1988, 30 were in Sioux Co, followed by Box Butte (13), Dawes (7), Kimball (7), Banner (1), Dundy (1), Hayes (1) and Lincoln (1) Cos. The estimate provided by Wheeler (2003) and attributed to the USFWS of 35 breeding pairs in Nebraska in 1992 is likely based on these surveys in the 1980s. No details were located regarding an eyrie reported from near Halsey, Thomas Co.
Surveys by Nebraska Prairie Partners (2008) found 21 and 29 occupied nests in 2007 and 2008, respectively, with at least 69 chicks in the Panhandle in 2007, most of those in Kimball Co and along the Niobrara River. These results, when compared to those surveys conducted in the 1980s suggest Ferruginous Hawk numbers and distribution has remained relatively stable in recent decades.
There are additional breeding season reports at the eastern edge of the range outlined above for Brown Co 5 Jun 1982 (Brogie and Mossman 1983), Keya Paha Co 23 Jun 1962, 30 Jun 2013 in Clay Co, and Polk Co 23 Jul 1985. Some or all of these sightings may be of sub-adult non-breeders or misidentifications. The specimen cited above, collected in Lancaster Co 10 Jun 1894, was taken at a time when grassland was probably more extensive than now.
A female banded in Jan 2004 near Janos, northern Mexico, summered in 2004 in western Nebraska (http://ferruginoushawk.org).
- Breeding phenology:
Incubation: late Apr-early May
Nestlings: 5 Jun- 22 Jun
Fledglings: 15 Jul
Fall: Sep 10,13,15<<<>>>winter
Early dates above, none with details, are from areas east of the breeding range, mostly Webster, Clay, and Adams Cos, where there have been several reports of wintering birds, though none recent. Young birds may wander widely as early as 40 days after fledging (Palmer 1988), which would allow for sightings as early as early Aug in areas where breeding was not noted (Bechard and Schmutz 1995).
The only documented records in the east are of an immature picked up near Osceola, Polk Co prior to 17 Sep in 1997 and taken to the Lincoln Rehabilitation Center (Omaha World Herald), a light-phase adult near Niobrara, Knox Co 3 Oct 1998 (Brogie 1999), an immature observed for two hours in Douglas Co 19 Oct 2007, a juvenile near Niobrara 26 Oct 2012, an adult in Knox Co 15 Nov 2009, and a light morph juvenile at Eppley Airfield, Omaha 18 Nov 2015. Other easterly reports, none with details, are 12 Oct 2003 Lancaster Co, 20 Oct 1999 Plattsmouth, and 18 Nov-3 Dec 2013 dark morph Douglas Co.
One banded in Alberta, Canada, 2 Jul 1936 was shot in Lincoln Co 12 Oct 1937 (Tout 1947), and a juvenile telemetered in 2007 in North Dakota died in southwest Nebraska in late Nov the same year; its device was recovered from an adjacent badger hole (http://www.ferruginoushawk.org/news.html).
- High counts: 10 between Merriman and Ainsworth 24 Nov 1994, 7 at one prairie dog town near Kearney 8 Dec 1996, and 5 seen in southwest Nebraska in 600 miles of driving 21-22 Oct 2004.
Winter: Wintering birds occur over at least the western two thirds of the state, often near prairie dog towns, although most breeders in the northwest depart in fall. Rosche (1982) considered Ferruginous Hawk a “casual winter visitant”. East of the mapped range above, there have been only three reports since 2000: a “dark juv.” was well-described at Branched Oak Lake, Lancaster Co 12 Feb 2016, and there are undocumented reports 5 Dec 2010 Cedar Co and 16 Dec 2010 Spring Creek Prairie, Lancaster Co. Jorgensen (2012) considered it accidental in winter in the eastern Rainwater Basin, citing two records, 2 Jan 1956 Adams Co, and a specimen, UNSM ZM17439, collected near Hastings 24 Jan 1993.
NGPC: Nebraska Game and Parks Commission
UNSM: University of Nebraska State Museum
USFWS: United States Fish and Wildlife Service
Bechard, M.J., and J.K. Schmutz. 1995. Ferruginous Hawk (Buteo regalis), version 2.0. In The Birds of North America (P. G. Rodewald, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bna.ferhaw.02
Brogie, M.A. 1999. 1998 (Tenth) Report of the NOU Records Committee. NBR 67: 141-152.
Brogie, M.A., and M.J. Mossman. 1983. Spring and summer birds of the Niobrara Valley Preserve, Nebraska: An annotated checklist. NBR 51: 44-51.
Bruner, L., R.H. Wolcott, and M.H. Swenk. 1904. A preliminary review of the birds of Nebraska, with synopses. Klopp and Bartlett, Omaha, Nebraska, USA.
Carlson, D., J. Dinan, and G. Wingfield. 1983. Ferruginous Hawk nesting and productivity 1983 summary. Nebraska Game and Parks Commission report, Lincoln, Nebraska, USA.
Carlson, D., J. Dinan, and G. Wingfield. 1984. Ferruginous Hawk nesting and productivity, 1984. Nebraska Game and Parks Commission report, Lincoln, Nebraska, USA
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Ducey, J.E. 1988. Nebraska birds, breeding status and distribution. Simmons-Boardman Books, Omaha, Nebraska, USA.
Johnsgard, P. A. 1980. A preliminary list of the birds of Nebraska and adjacent Great Plains states. Published by the author, University of Nebraska, Lincoln, USA.
Johnsgard, P.A. 1997. The birds of Nebraska and adjacent plains states. Occasional Papers No. 6, Nebraska Ornithologists’ Union. Lincoln, Nebraska, USA.
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Nebraska Prairie Partners. 2008. Western Nebraska Final Nebraska Environmental Trust Research Report-2005-07. Bird Conservancy of the Rockies, Brighton, Colorado, USA.
Palmer, R.S., ed. 1988. Handbook of North American birds. Vol. 4. Diurnal Raptors (Part 1). Yale University Press, New Haven, Connecticut, USA.
Rosche, R.C. 1982. Birds of northwestern Nebraska and southwestern South Dakota, an annotated checklist. Cottonwood Press, Crawford, Nebraska, USA.
Rosche, R.C. 1994. Birds of the Lake McConaughy area and the North Platte River valley, Nebraska. Published by the author, Chadron, Nebraska, USA.
Shupe, S., and R. Collins. 1983. A winter roadside survey of hawks in eastern Nemaha County, Nebraska. NBR 51: 19-22.
Tout, W. 1947. Lincoln County birds. Published by the author, North Platte, Nebraska, USA.
Wheeler, B.K. 2003. Raptors of Western North America. Princeton University Press, Princeton, New Jersey, USA.
Wingfield, G. 1985. Ferruginous Hawk nesting and productivity, 1985 summary. Nebraska Game and Parks Commission report, Lincoln, Nebraska, USA.
Wingfield, G. 1986. Ferruginous Hawk nesting and productivity, 1986. Nebraska Game and Parks Commission report, Lincoln, Nebraska, USA.
Wingfield, G. 1987. Ferruginous Hawk nesting and productivity, 1987. Nebraska Game and Parks Commission report, Nebraska, USA.
Wingfield, G. 1988. Ferruginous Hawk nesting and productivity, 1988. Nebraska Game and Parks Commission report, Nebraska, USA.
Silcock, W.R., and J.G. Jorgensen. 2018. Ferruginous Hawk (Buteo regalis), Version 1.0. In Birds of Nebraska — Online. www.BirdsofNebraska.org