Blane Klemek: Northern goshawk is one of Minnesota’s top avian predators
On a recent deer hunt in Kittson County about 30 miles from the Manitoba border, I found myself walking slowly on a deer trail that offered some respite from the mostly impenetrable hazel brush understory of the predominately aspen woodland. Having spent over an hour picking my way through the dense brush in hopes of surprising a deer, I was relieved to be free of the thickets.
As I walked slowly on the trail that weaved through slough grass, alder, and a few clumps of aspen, I saw a movement ahead of me. Stopping immediately to identify the unknown object, I quickly realized that I was looking at a flying bird — and a large bird at that. In the next two seconds the bird that suddenly appeared before me had whizzed by; but that flash was all I needed to make a positive ID. Goshawk!
Of the northern goshawk, which was formerly called “eastern goshawk”, Arthur Cleveland Bent wrote, “From the heavily forested regions of Canada, the main summer home of the goshawk, this bold brigand of the north woods, the largest, the handsomest, and the most dreaded of the Accipiter tribe, swoops down, in winter, upon our poultry yards and game covers with deadly effect. He is cordially hated, and justly so, by the farmer and sportsman; and for his many sins he often pays the extreme penalty.”
The northern goshawk (Accipiter gentilis) occurs throughout northern Minnesota in mostly mixed deciduous/coniferous forests. A large bird (the largest Minnesota accipiter) with body lengths of up to 21 inches, wingspans to 41 inches, and body weights of over two pounds, the bird is more than capable of capturing large prey.
This beautiful and secretive hawk of the forest is of particular interest to natural resource professionals and birders alike. Though not considered as a species endangered, threatened, or of special concern, the Minnesota Department of Natural Resources has nonetheless proposed management considerations that benefits this special raptor so it can continue to remain one of Minnesota’s top avian predators inhabiting the state’s northern woodlands.
Northern goshawks are unlike many raptors found here. To more closely monitor the raptors throughout its northern Minnesota range, biologists conducted nest surveys and radio telemetry studies to track the birds. This led to the discovery that goshawks do not migrate in the fall like most hawks and falcons do. In fact, northern goshawks stay in Minnesota all winter long.
The breeding territories of northern goshawks encompass large areas. According to a study conducted in 2001, the average size in acres of a goshawks’ breeding territory was estimated at between 12,000 and 20,000 acres for the eleven bird-pairs monitored. Interestingly, a breeding pair will construct several alternative nests — up to eight — near the active nest.
Aside from the overall size of northern goshawks, distinctive markings set them apart from other accipiters. As a note, accipiters, when compared to buteos (red-tailed hawks, rough-legged hawks, etc.) typically have longer, narrower tails and shorter, broader wings than most of the latter group’s members.
In any event, no other accipiter, of which the Cooper’s and sharp-shinned hawks are classified as well, has a more boldly patterned head. The adult goshawk displays a dark cap, a bold white “eye-brow” (or supercilium as it is technically called), and a broad black eye-band. Adult plumage coloration is grayish overall, while immatures are brown with brown-on-white streaked bellies.
Prey items making up the diet of goshawks include many species of birds and mammals. On the menu include ruffed grouse, species of ground and tree squirrels and other small rodents, hares and rabbits, and songbirds. Their hunting style is swift, aggressive, and efficient.
Goshawks have been known, as my friend can attest, to swoop at humans that venture too close to their nesting area. So determined is their pursuit at fleeing prey, goshawks have been observed chasing barnyard fowl into buildings. Bounties were commonly paid in some states for species of hawks, including the goshawk, during the early 1900s.
Hunting within the forest or along forested edges and openings, northern goshawks will usually perch from vantages within the canopy and ambush unsuspecting prey below. They subdue and kill prey quickly with their sharp talons. Goshawks will often surprise prey by flying above dense cover, spooking the quarry into flushing, and overtaking them.
Nesting for Minnesota’s goshawks begins by April with egg laying, incubation, and hatching all occurring by the end of May. Clutch sizes range from two to five. Though the actual northern goshawk population is unknown in Minnesota, today’s population is considered stable, which means that Minnesota’s northern goshawks are finding suitable habitat for hunting and raising offspring in.
Couple this with increased public awareness and appreciation, along with implementing specific forestry and wildlife management practices within the birds’ range, more sightings of this special raptor will surely be ours as we get out and enjoy the great outdoors.
To learn more about northern goshawks and habitat management, visit this web page on the DNR’s website to watch this interesting video: http://www.dnr.state.mn.us/nongame/videos/goshawks.html
(Klemek is the DNR Area Wildlife Supervisor in Detroit Lakes. You can contact him at firstname.lastname@example.org.)