Peregrine falcons: the cheetahs of the avian world
Peregrine falcons, as their English name indicates, belong to the family Falconidae and are large raptors, or birds of prey. They are roughly the size of a crow, with white or beige underbellies striped with black, bluish-gray backs and wings, and black or blue-gray heads. One of the most widely seen birds on the planet, they are also the fastest animal in existence, reaching dive velocities that would cause many birds to suffocate. As such, peregrine falcons are among the most popular of the raptors, and their prowess as hunters has made them beloved of falconers as well.
The habitat of the peregrine falcon
There are thought to be anywhere from 17 to 19 different subspecies of peregrine falcon. Seen just about everywhere on the planet, peregrine falcons even breed on the Arctic tundra. They avoid the farthest reaches of the polar regions, however, and also are not seen in most rainforests and high mountain areas. Of all the world’s ice-free landmasses, New Zealand is the only one on which peregrine falcons do not appear. Even so, they are a decidedly cosmopolitan bird: Peregrine falcons are as comfortable in big cities as they are in remote wildernesses, nesting on high-rises and suspension bridges, and keeping the local duck and pigeon populations in check.
Peregrine falcon size and lifespan
As is characteristic of raptors, peregrine falcons are sexually dimorphic, meaning the male and female birds are distinguished by physical differences beyond their reproductive organs. Female peregrine falcons, for example, are larger than their males counterparts, sometimes by as much as 30%. Males weigh around 330 – 1,000 g (.73 – 2.20 pounds), while females can range from 700 – 1,500 g (1.5 – 3.3 pounds). In general, peregrine falcons have a wingspan between 74 – 120 cm (29 – 47 inches) and a body length of 34 – 58 cm (13 – 23 inches). They live up to about 15 years in the wild, with high mortality rates in their first year (59 – 70%) that tend to decline with each additional year of adulthood. Though peregrine falcons are deadly hunters, they may still fall prey to larger owls and hawks. There are a number of pathogens and parasites that can also kill them.
The diet of the peregrine falcon
Peregrine falcons chiefly feed on fellow birds (and occasionally other animals) of lesser size, though they do not shy away from sating their appetites by other means when necessary. Small reptiles will do in a pinch, and even insects are palatable enough when there’s little else around. But the preferred peregrine falcon diet consists of doves, pigeons, waders, songbirds, and waterfowl. They do not often hunt mammals, though mice, hares, rats, voles, shrews, and even bats are by no means shunned given the right circumstances. Peregrine falcons usually hunt during the hours of dawn and dusk, when their prey is most active, and their method of hunting has been the subject of many a YouTube video. Peregrine falcons take their prey mid-flight, ascending high overhead, then dropping into a dart-like dive and striking their prey with their closed foot. Once accomplished, peregrine falcons bank back around and grab their falling feathery morsel.
Peregrine falcon diving and falconry
If peregrine falcons are most known for their speed in flight, it is their high-altitude hunting dive (called a stoop) that is responsible for it. During these stoops, peregrine falcons achieve their maximum speed, enough to cause lung damage in most animals. But peregrine falcons have bony tubercles on their nostrils that channels airflow away from this sensitive area, allowing for easier breathing during their rapid descents. Their eyes are likewise protected by third eyelids, called nictitating membranes, that clear away in-flight debris by flushing tears across their eyes. In addition to these adaptations, peregrine falcons have air sacs that prevent their lungs from deflating during exhalation.
So, finally, how fast are peregrine falcons?
During their bolt-like hunting stoops, peregrine falcons can reach speeds that rival the fastest race cars: around 320 kph (200 mph), and one falcon has even been clocked at 389 kph (242 mph). In ordinary flight, they take it easy, averaging speeds of 40 – 60 mph. Naturally, the anatomy of peregrine falcons has much to do with its meteoric dive velocity. Due to their large keels, which are bird breastbones to which wing muscles are attached, peregrine falcons have a lot of room for muscle fibers. This additional muscle of course translates to additional wing power. But peregrine falcons also have aerodynamic wings, which are pointed and capable of folding close to their bodies, creating a streamlined figure that cuts through the air like a blade. Their feathers are also stiff and slim, reducing wind resistance that affects birds with looser feathers and broader wings. Peregrine falcon hearts also beat 600 – 900 times per minute, delivering oxygen at high rates and enabling four wing beats every second.