American Kestrel

STATUSLeast Concern

COMMON NAME (SCIENTIFIC NAME)Falco sparverius

DIETInsects, song birds, reptiles, amphibians, and small mammals

RANGENorth and South America

HABITATOpen woods, orchards, fields, cities and parks to deserts, grasslands, and alpine meadows

American Kestrel

American Kestrels are 22-Cm in length and weigh between 2.8-5.8 ounces. With a wingspan between 51 to 61 centimeters, these small falcons are roughly the same size as a Mourning Dove.

Males and females of this species look very different. Both genders are reddish-brown with black spots on their dorsal surfaces and have pale ventral sides. They also have black marks on either side of their pale face. Males have a gray-blue head and wings while females are colored more red-brown in these locations.

Also known as the Sparrow Hawk the Kestrel is the smallest and most common falcon. This bird can be seen “pumping” their tails to aid in balance while perching. Because of its small stature, the Kestrel is often blown in the wind and thus can have an erratic flight pattern. Despite this tendency, this bird is still capable of hovering over a field in search of prey.

The most common call of the American kestrel is a shrill series (generally 3 to 6) of killy notes that lasts just over a second.

Related To:
Peregrine falcon (duck hawk) and Merlin falcon (pigeon hawk), Bird of Prey: Wild Raptor -Carnivore

Habitat/Range:
Kestrels are widely distributed throughout North and South America.  They have adapted readily to humans and nests in large cities throughout the U.S. Their range covers the entire United States, Southern Alaska, British Columbia, Great Lakes, New England, and American tropics.

Their habitats range from open woods, orchards, fields, cities and parks to deserts, grasslands, and alpine meadows. It is very common to see this falcon perched on roadside power lines in more open areas where it can easily hunt for food. They favor any area with low ground vegetation and sparse amounts of trees. They are attracted to man made areas such as pastures, parks, and towns.

Diet in Wild:
American Kestrels regularly eat a large variety of items including Insects, song birds, reptiles, amphibians, and small mammals.  Commonly taken insects include grasshoppers, cicadas, beetles, dragonflies, butterflies and moths. Spiders and scorpions are eaten as well.  Commonly hunted mammals include mice, shrews, snakes, frogs and bats. This species rarely feeds on carrion except for prey that it has previously killed and cached.

Diet in Zoo:
Commercially raised and humanely killed mice. Frozen packaging not only ensures freshness but also cleanliness.  All of the Education Birds of Prey are not able to hunt on their own due to injuries, so live prey could never be offered. Diet enrichments ensure stimulation for the birds.

Predators:
Great horned owls, red-tailed hawks and prairie falcons. It is mostly eggs and young birds that are preyed on, however adults do sometimes fall prey to these animals. When on the ground they can fall prey to bobcats, skunks, coyotes, and raccoons.

Life Cycle and Social Structure:
Pairs of Kestrels will exchange food as gifts (often male feeding the female) while courting. Before selecting a mate, it is not uncommon for several kestrels to group together for the beginnings of courtship. American Kestrels are obligate secondary cavity nesters, which means they do not excavate their own cavities, but nest in existing natural and manmade cavities, including tree cavities, woodpecker holes, abandoned buildings, cliff/outcrop potholes, creases and cavities, and nest boxes. Kestrels are common in both farmlands and low-density suburban areas, as well as in open and semi-open natural habitats ranging from deserts to woodlands. They sometimes also nest in urban areas. The male is responsible for finding several nest cavity options for the female to see before she decides on a nesting location.

A female kestrel will lay somewhere between 3-7 white, creamy, pink or pale buff dotted brown eggs (35X29mm), which will be incubated for 29-30 days. While males may occasionally take over incubation duties, it is the female that does most of the sitting. The male will feed the female during and shortly after incubation. The young will stay with adults after fledging.

One of the continent’s most widespread raptors, kestrels breed in eastern and western North America, north to the tree line and south into most of Central and South America. The American Kestrel is a partial migrant, with large proportions of Canadian and U.S. populations migrating south in autumn. American Kestrels breeding in northern portions of their range are more migratory than those breeding farther south, and birds in northern areas migrate farther than those in southern areas. Many southern populations are sedentary, and this combination of factors produces a leap-frog migration pattern.

Although larger falcons, like Merlins and Peregrine Falcons, often fly to the tropics to overwinter, most kestrels breed in North America overwinter in the United States and Mexico. A small proportion, however, migrate as far south as northern South America.  Males winter farther north than females, and in more wooded habitats, possibly because females generally arrive on the winter range before males (Smallwood 1987), although it has also been suggested that females competitively exclude males from optimal habitats (Ardia and Bildstein 1997).

Life Span:
In the wild, young Kestrels have a survival rate of about 50% but that rate can go up if the nest is in a man made nesting box which provides better protection. If an American kestrel survives its first few years, it can live to be 9 to 11 years old in the wild. As with most birds, captive Kestrels can live longer than those in the wild, reaching ages of 14 or even 17 years old.

 Interesting Facts:

  • The American Kestrel is the smallest and most numerous of the North American falcons.
  • While the young birds are practicing their hunting skills, kestrels will often hunt in family units.
  • There is a color (plumage –feather pattern) difference between the sexes. The male kestrel has blue on its wings, while the female is mostly brown with streaking, this is called sexual dimorphism.
  • The scientific name comes from the Latin word falco, meaning hook-shaped (falcate) and may refer to the beak or claws, and espervier, the Latinized French word for a sparrow hawk and probably refers to its size and prey.
  • The American Kestrel has been called a Sparrow Hawk, Killy Hawk (for the sound they make), or Windhover (for their ability to hover).
  • The American Kestrel can cache extra food in clumps of grass, tree roots, fences, tree roots, etc. to save for later and to hide it from other animals

Conservation Message:
Kestrels are an animal that prefers open habitats like farmlands and meadows.  Unfortunately due to the increase in development, these areas are being used to create new parking lots, housing developments and shopping malls. Should these large open areas disappear, many species such as the American Kestrel will be unable to adapt to hunting in a different habitat. Kestrels are important to our environment since they are a top predator in the food chain. Kestrels are also important to the agricultural community since they hunt pest species such as large insects and mice that destroy crops.

Trash and litter along the roadways are attracting rodents, therefore attracting BOP like the American Kestrel. Many are then being hit by cars and injured or killed.

What You Can Do:
Because Kestrels cannot make their own nest cavities, these birds lose valuable nesting areas every time a dead tree is cut down or an old forest is cleared. In addition, food sources for these birds are going down in numbers as well. Being a bird that can eats insects, pesticides spread on farms drastically decrease the amount of available prey for the American Kestrel. Building nest boxes on the edge of your lawn or field provides these birds with a safe place to raise their young, close to a habitat suitable for them to hunt. Buying produce from local farms that use sustainable and ecologically friendly farming methods can also help maintain the kestrel population.

Avoid throwing any trash or litter (apple cores banana peels etc outside especially along roadways)You could also volunteer to help with a highway litter patrol to help pick up trash along the highways.

Bibliography
The Peregrine Fund. “American Kestrel” 25 January, 2008.   http://www.allaboutbirds.org/