Buteos are fairly large birds. Total length can vary from 30 to 75 cm (12 to 30 in) and wingspan can range from 67 to 170 cm (26 to 67 in). The lightest known species is the roadside hawk,[a] at an average of 269 g (9.5 oz) although the lesser known white-rumped and Ridgway's hawks are similarly small in average wingspan around 75 cm (30 in), and average length around 35 cm (14 in) in standard measurements. The largest species in length and wingspan is the upland buzzard, which averages around 65 cm (26 in) in length and 152 cm (60 in) in wingspan. The upland is rivaled in weight and outsized in foot measurements and bill size by the ferruginous hawk. In both of these largest buteos, adults typically weigh over 1,200 g (2.6 lb), and in mature females, can exceed a mass of 2,000 g (4.4 lb).[5][6][7][8] All buteos may be noted for their broad wings and sturdy builds. They frequently soar on thermals at midday over openings and are most frequently seen while doing this. The flight style varies based on the body type and wing shape and surface size. Some long-winged species, such as rough-legged buzzards and Swainson's hawks, have a floppy, buoyant flight style, while others, such as red-tailed hawks and rufous-tailed hawks, tend to be relatively shorter-winged, soaring more slowly and flying with more labored, deeper flaps.[5] Most small and some medium-sized species, such as, red-shouldered hawk, often fly with an alternation of soaring and flapping, thus may be reminiscent of an Accipiter hawk in flight, but are still relatively larger-winged, shorter-tailed, and soar more extensively in open areas than Accipiter species do.[5][9] Buteos inhabit a wide range of habitats across the world, but tend to prefer some access to both clearings, which provide ideal hunting grounds, and trees, which can provide nesting locations and security.[6][7]

DietAll Buteo species are to some extent opportunistic when it comes to hunting, and prey on almost any type of small animal as it becomes available to them. However, most have a strong preference for small mammals, mostly rodents. Rodents of almost every family in the world are somewhere preyed upon by Buteo species.[5][6][7] Since many rodents are primarily nocturnal, most buteos mainly hunt rodents that may be partially active during the day, which can include squirrels and chipmunks, voles, and gerbils. More nocturnal varieties are hunted opportunistically and may be caught in the first or last few hours of light.[5][7] Other smallish mammals, such as shrews, moles, pikas, bats, and weasels, tend to be minor secondary prey, although can locally be significant for individual species.[5][7] Larger mammals, such as rabbits, hares, and marmots, including even adult specimens weighing as much as 2 to 3 kg (4.4 to 6.6 lb), may be hunted by the heaviest and strongest species, such as ferruginous,[7][10][11] red-tailed[12] and white-tailed hawks.[13] Birds are taken occasionally, as well. Small to mid-sized birds, i.e. passerines, woodpeckers, waterfowl, pigeons, and gamebirds, are most often taken. However, since the adults of most smaller birds can successfully outmaneuver and evade buteos in flight, much avian prey is taken in the nestling or fledgling stages or adult birds if they are previously injured.[5][7] An exception is the short-tailed hawk, which is a relatively small and agile species and is locally a small bird-hunting specialist.[14] The Hawaiian hawk, which evolved on an isolated group of islands with no terrestrial mammals, was also initially a bird specialist, although today it preys mainly on introduced rodents. Other prey may include snakes, lizards, frogs, salamanders, fish, and even various invertebrates, especially beetles. In several Buteo species found in more tropical regions, such as the grey-lined hawk, reptiles and amphibians may come to locally dominate the diet.[5] Swainson's hawk, despite its somewhat large size, is something of exceptional insect-feeding specialist and may rely almost fully on crickets and dragonflies when wintering in southern South America.[15][16] Carrion is eaten occasionally by most species, but is almost always secondary to live prey.[5] The importance of carrion in the Old World buzzard species is relatively higher since these often seem slower and less active predators than their equivalents in the Americas.[17][18][19] Most Buteo species seem to prefer to ambush prey by pouncing down to the ground directly from a perch. In a secondary approach, many spot prey from a great distance while soaring and circle down to the ground to snatch it.[5]