{"id":2429,"date":"2019-11-07T21:24:11","date_gmt":"2019-11-07T21:24:11","guid":{"rendered":"http:\/\/wordpress.viu.ca\/biol325\/?p=2429"},"modified":"2019-11-22T04:07:17","modified_gmt":"2019-11-22T04:07:17","slug":"a-living-missile-peregrine-falcon","status":"publish","type":"post","link":"https:\/\/wordpress.viu.ca\/biol325\/2019\/11\/07\/a-living-missile-peregrine-falcon\/","title":{"rendered":"Peregrine Falcon: A Living Missile"},"content":{"rendered":"\n

Introduction to the Peregrine Falcon<\/h2>\n\n\n\n

Description and Identification<\/strong><\/h4>\n\n\n\n

            The Peregrine Falcon (Falco peregrinus<\/em>) belongs to the Order Falconiformes and Family Falconidae (Sibley, 2016)<\/a>. There are twenty-two subspecies worldwide but only three are found in North America (Nature Conservancy Canada, n.d.)<\/a>. Of the three, the first is a resident of British Columbia or Alaska and the second and third are migrants from South or from the high Arctic (Nature Conservancy Canada, n.d.)<\/a>. <\/p>\n\n\n\n

In general, both sexes of Peregrine Falcon adults have a dark black head with black sideburns and appear to have a blue-gray plumage with horizontal bars on their breasts (Cornell University: All About Birds, n.d.)<\/a>. They also have a yellow cere and yellow feet (Cornell University: All About Birds, n.d.)<\/a>. The juveniles are a darker brown with a blueish cere and have vertical bars all over their chests (Cornell University: All About Birds, n.d.)<\/a>. There is some variation in darkness of plumage that occurs depending on geographic location in which there is a scale from a darker shade to a lighter shade resulting in the classification of Pacific (darker), Anatun or Tundra (lighter) (Sibley, 2016)<\/a>. Also, an important feature to look for when examining any falcon species is their tomial tooth which is specialized for killing their prey. <\/p>\n\n\n\n

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Figure 2: Peregrine Falcon in Juvenile Plumage with vertical chest bars. Note the blueish cere and feet. (Spencer, 2018)<\/a> <\/figcaption><\/figure><\/div>\n\n\n\n
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Figure 1: Peregrine Falcon in adult plumage with horizontal bars on chest. Note the yellow cere and feet. (Gibson, 2016)<\/a> <\/figcaption><\/figure>\n\n\n\n

Although Peregrine Falcons are generally the size of a crow, they are considered to be one of the largest falcons but the females are typically larger than the males (Cornell University: All About Birds, n.d.)<\/a>. It is often easy to confuse Peregrines with other species such as Merlins and Gyrfalcons so it is important to examine their wings and tail! Both their tail and wings are long and pointed and they have underwings that are uniformly barred (Cornell University: All About Birds, n.d.)<\/a>.    <\/p>\n\n\n\n

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Figure 3: Peregrine Falcon in flight showing body, wing and tail shape (Schain, 2011)<\/a><\/figcaption><\/figure><\/div>\n\n\n\n

Another identifying feature that the Peregrine Falcon possesses is its unique song and calls. In general, their calls are loud and quite harsh sequences of “kak, kak, kak” (Cornell University: All About Birds, n.d.)<\/a> as heard in audio 1 & 2. Their call is used to announce fear in some way such as when a predator is near. Predators that could result in both the calls heard in Audio 1 & 2 could include Gyrfalcons, Eagles, Great-Horned Owls or other falcons (Cornell University: All About Birds, n.d.)<\/a>. <\/p>\n\n\n\n

Audio 1: Peregrine Falcon’s alarm call heard in Italy (Inaudi, 2010)<\/a>. <\/figcaption><\/figure>\n\n\n\n
Audio 2: Peregrine Falcon’s call heard in California, USA (Lambert, 2015)<\/a>.<\/figcaption><\/figure>\n\n\n\n

Their individualized song is much more common in terms of courtship. In Audio 3, you can hear the beautiful song of a male Peregrine Falcon attracting a nearby female to a new nesting location. <\/p>\n\n\n\n

Audio 3: Male Peregrine Falcon song used to attract female to new nest box in Poland (Matusiak, 2015)<\/a>.<\/figcaption><\/figure>\n\n\n\n

Distribution & Habitat<\/strong><\/h4>\n\n\n\n

         Peregrine Falcons are definitely not picky in terms of their habitat and nesting locations. They can be found living anywhere from tundras to desert mountains and anywhere in between (Audubon, 2019)<\/a>. They are often on cliffs, in the open country and are also frequently forced to live within cities where they can find perches (Audubon, 2019)<\/a>. When outside cities, they are often spotted along the coast lines where they will frequently adventure far out above the ocean (Audubon, 2019)<\/a>. <\/p>\n\n\n\n

As you can probably already assume from the Peregrine Falcon’s very diverse habitats and nesting areas, their distribution on Earth also has great diversity. They can be found on all of the continents except for Antarctica (Nature Conservancy Canada, n.d.)<\/a>. <\/p>\n\n\n\n

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Figure 4: Map showing general distribution of the Peregrine Falcon worldwide in 2019 where purple represents presence of a Peregrine Falcon
(eBird, 2019)<\/a><\/figcaption><\/figure><\/div>\n\n\n\n
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Figure 5: Peregrine Falcon distribution throughout North America showing areas of breeding, non-breeding, migration and year-round residence (Cornell University: All About Birds, n.d.)<\/a> <\/figcaption><\/figure><\/div>\n\n\n\n

Behaviour<\/h4>\n\n\n\n

This spectacular bird is often seen soaring high above or perched along edges at nesting sites. <\/p>\n\n\n\n

Peregrine Falcons are very successful hunters who feed on a variety of birds and bats. A total of 450 different species of birds has been documented as their prey in North America alone and predicted to be around 2000 species worldwide (Cornell University: All About Birds, n.d.)<\/a>. Prey size is not really an issue as they eat birds as big as a sandhill crane and as small as hummingbirds (Cornell University: All About Birds, n.d.)<\/a>. They have also been known to steal food such as fish and rodents from other raptors (Cornell University: All About Birds, n.d.)<\/a>. <\/p>\n\n\n\n

Many methods are used to catch their prey but the most common way involves a stoop from great heights where the Peregrine Falcon drops down upon its prey to either directly grab it or hit it with its feet to stun it (Mills, Hildenbrandt, Taylor, & Hemelrijk, 2018)<\/a>. This often occurs in wide open clearings which allow for enough space to perform their stoop (Mills, Hildenbrandt, Taylor, & Hemelrijk, 2018)<\/a>. Once stunned the prey is picked up by the neck, killing it in the process (Cornell University: All About Birds, n.d.)<\/a>. Other methods include level pursuit, hunting on the ground or picking birds straight out of flocks (Cornell University: All About Birds, n.d.)<\/a>.<\/p>\n\n\n\n

Their nesting behaviour involves the males finding a few open perches on the ledges of cliffs or buildings and then the female comes along and takes her pick (Cornell University: All About Birds, n.d.)<\/a>. An interesting fact about their nest building is that they don\u2019t really do it \u2013 at least not in the traditional way but instead undergo a “ritualized scraping” (Cornell University: All About Birds, n.d.)<\/a>. This scraping creates a depression at the nest area that has a diameter of 9 inches and a depth of 2 inches (Cornell University: All About Birds, n.d.)<\/a>. These nest sites are used for one brood of anywhere between 2-5 eggs (Cornell University: All About Birds, n.d.)<\/a>. <\/p>\n\n\n\n

An interesting connection showing how truly clever these birds are occurs between Peregrine Falcons’ nesting behaviours and their hunting style within New York City at the Empire State Building. DeCandido and Allen (2006)<\/a> determined in their study that the Peregrine Falcon’s were nesting on skyscrapers and conducting nocturnal hunting of migratory birds. The skyscrapers provided a high enough perch so they could still conduct their stoops while the bright lights of the city often caused disorientation and confusion to their prey resulting in much easier predation (DeCandido & Allen, 2006)<\/a>. <\/p>\n\n\n\n

Flight: The World’s Fastest Animal <\/h4>\n\n\n\n
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Figure 6: The development of a Peregrine Falcon’s vertical dive showing its ability to undergo morphing wing.
Photo: (Wildlifetog, 2018)<\/a> <\/figcaption><\/figure><\/div>\n\n\n\n

One of the most fascinating abilities of the Peregrine Falcon is their speed during diving flight. They have been labelled as one of the fastest birds in the world due to their ability to reach speeds of 150km\/hr during horizontal flight and up to 320km\/hr during vertical dives (Ponitz, Schmitz, Fischer, Bleckmann, & Br\u00fccker, 2014)<\/a>. To increase flight aerodynamics, birds often undergo morphing wing which is when a bird changes their wing shape (Ponitz, Schmitz, Fischer, Bleckmann, & Br\u00fccker, 2014)<\/a>. A Peregrine Falcon’s morphing wing follows the sequence of diamond shaped wings, a tight vertical tuck and a tight wrapped vacuum wrap as their speed increases (Ponitz, Schmitz, Fischer, Bleckmann, & Br\u00fccker, 2014)<\/a>. Another important aspect of their flight is that they show great maneuverability at these incredibly fast speeds which is used during their courtship behaviour (Ponitz, Schmitz, Fischer, Bleckmann, & Br\u00fccker, 2014)<\/a>. <\/p>\n\n\n\n

With such great speeds, the Peregrine Falcon has certain adaptations to protect them during high speeds that have even been examined when trying to solve jet aircraft problems (DeYoung, n.d.)<\/a>. To protect their lungs during flight, they have cone-shaped bones near their nostrils called baffles which deflect shockwaves of air (DeYoung, n.d.)<\/a>. A similar cone approach has been used in aircraft engine openings (DeYoung, n.d.)<\/a>. Another adaptation has to do with their black sideburns which are used to minimize sun glare enhancing their hunting ability (DeYoung, n.d.)<\/a>. <\/p>\n\n\n\n

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