Birds
Ferruginous Hawk
Buteo regalis · also called ferruginous hawks
Perched on a low rise overlooking a prairie dog colony, a ferruginous hawk watches patiently, its rusty, iron-coloured plumage blending into the open grassland it depends on as completely as its diet depends on the colony below.
Overview
The ferruginous hawk, Buteo regalis, is the largest soaring hawk species in North America, native to open grassland and prairie habitat across the central and western United States and southern Canada. Its rusty plumage and close dietary reliance on ground squirrels and prairie dogs make it one of the more habitat-specific and prey-dependent large hawks on the continent.
A hawk whose fortunes rise and fall with the prairie dog
Few large hawks depend as heavily on a single type of prey community as the ferruginous hawk does on prairie dog and ground squirrel colonies, meaning the species’ wellbeing is tied directly to how much intact prairie remains for those colonies to thrive in.
Status
Least Concern — present across suitable grassland habitat, though declining in areas where prairie has been converted to farmland.
Ferruginous Hawk: common questions
Why is it called the ferruginous hawk?
A ferruginous hawk displays rusty, iron-rust-coloured plumage on the legs and back, a distinctive colouration that gave the species its common name, since ferruginous is a term specifically describing that reddish-brown, iron-oxide colour.
What does the ferruginous hawk mainly eat?
The ferruginous hawk specialises heavily in hunting ground squirrels and prairie dogs, making its population closely tied to the health and abundance of these prey species' colonies across the open grassland habitat it occupies.
Why does the ferruginous hawk sometimes nest on the ground?
In open, treeless prairie habitat lacking tall trees, a ferruginous hawk will sometimes nest directly on the ground or on low structures rather than in an elevated tree nest, an adaptation to the genuinely open terrain much of its range consists of.
Why has the ferruginous hawk declined in some areas?
Ferruginous hawk populations have experienced regional declines linked to the conversion of native prairie to agricultural land, which reduces both suitable open hunting habitat and the prairie dog and ground squirrel colonies the species depends on heavily for food.