40 Fun Facts About American Kestrel

DNA studies place falcons like the American kestrel closer to which birds than to hawks?

Parrots and songbirds are the nearest living relatives of falcons. The hooked look that falcons share with eagles and other birds of prey says little about their family tree.

Which light, invisible to humans, may let an American kestrel follow the urine trails that voles leave in grass?

Ultraviolet light was the cue in a 1995 study, which found Eurasian kestrels drawn to vole scent marks. A 2013 study cast doubt, finding vole urine gives raptors no reliable visual signal.

Which tiny stinging insects join hawks, owls and rat snakes on the list of animals that prey on American kestrels?

Fire ants are on the list of kestrel predators, alongside crows and corn snakes. Being one of the smallest birds of prey means often being the hunted one.

One raptor conservation group says a small American kestrel weighs about the same as 34 of which US coins?

Pennies make the point: 34 of them weigh about three ounces, the same as a small kestrel. Even the heaviest birds reach only about six ounces.

American kestrels have been caught on live TV hunting moths drawn to the bright lights of which venues?

Sports stadiums give kestrels a night shift: the birds perch on light standards or foul poles and snatch insects out of the beams during evening games.

Unlike hawks, which kill with their feet, a falcon such as the American kestrel finishes off prey using what?

Its beak has a tooth-like point on the side called a tomial tooth, the killing tool of the whole falcon family. Hawks and eagles rely on their talons instead.

The two black spots on the back of an American kestrel's head are thought to ward off attackers by mimicking what?

A pair of eyes seems to stare from the back of the head, so a predator may think it has been noticed. The spots are called ocelli, and their purpose is still debated.

A courting male American kestrel brings his mate gifts of dead mice that are missing which part?

Their heads are gone: headless mice and dead lizards are a male's courtship gifts. Pairs that form this way often stay together for years and return to the same nest site.

Before a 1983 checklist change, which misleading name did most North Americans use for the American kestrel?

Sparrow hawk was the bird's usual name until 1983, borrowed from an unrelated Old World hunter. The kestrel is a falcon, so ornithologists renamed it.

Where do American kestrel chicks squirt their droppings to keep themselves clean inside a cramped tree cavity?

Onto the nest walls it goes: each chick backs up and squirts, so the mess dries on the sides and stays off the brood. The cavity still ends up a smelly place.

American kestrels cannot dig their own nest holes, so pairs often move into old cavities made by which birds?

Woodpeckers do the carpentry, and kestrels take over the finished holes. The male scouts possible cavities and shows them to the female, who makes the final choice.

What color are the wings of an adult male American kestrel, the easiest way to tell him from a rusty-winged female?

Slate blue wings mark the male, while the female's wings are rusty with black barring. Both sexes wear two black slashes down each side of the face.

North America's smallest falcon, the American kestrel, is about the size of which common backyard bird?

Mourning dove is the comparison birders use, though kestrels vary a lot: a large northern female can be about twice the size of a small southern male.

What does a hunting American kestrel face into so that it can hover in one spot above an open field?

The wind holds the bird up as it flaps in place, scanning the ground below. Most hunting is still done from a perch, which costs far less energy.

Which insect, a summer staple of the American kestrel's diet, gives the bird one of its folk names?

Grasshopper hawk is an old country name for the kestrel. Insects make up much of the warm-weather menu, with rodents, lizards and small birds filling in.

The American kestrel's old nickname "killy hawk" comes from which feature of the bird?

Its shrill call, a rapid killy-killy-killy, is given when the bird is excited or upset. Females are larger than males and tend to sound lower-pitched.

Which North American raptor do falconers rate as swifter and more muscular than the similar-sized American kestrel?

Merlin is the kestrel's athletic cousin, built for long aerial chases. The kestrel's leaner frame suits ambush hunting and gets by on less food each day.

When hunting is good, what does an American kestrel do with a surplus kill?

It hides it for later: surplus kills go into grass clumps, fence posts, tree roots and cavities, saved for lean times and kept away from thieves.

Which habit, often shown just after landing, helps birders pick out a perched American kestrel from far away?

Pumping its tail up and down is the kestrel's giveaway on a distant post. The bird also bobs its head just before launching at prey on the ground.

Where along a country road are drivers most likely to spot an American kestrel scanning the ground for prey?

On power lines, where the birds sit and scan for dinner, kestrels are easiest to spot. Fence posts and telephone poles are also favorite lookouts.

Which naturalist gave the American kestrel its scientific name, Falco sparverius, in 1758?

Carl Linnaeus named the bird from a description and painting made in the Carolinas, and gave its home simply as America. Later scientists narrowed that to South Carolina.

Which place marks the far southern end of the American kestrel's range, which begins in Alaska?

Tierra del Fuego is the southern tip of the kestrel's range, which at the other end reaches above the Arctic Circle. No other falcon in the Americas is as common.

American kestrels have been found living above 4,500 metres, or about 14,800 feet, in which mountain range?

The Andes mark the high point for a bird that is equally at home in deserts, city suburbs and north of the Arctic Circle.

Despite decades of decline across North America, which IUCN Red List category does the American kestrel hold?

Least Concern reflects a global population in the millions across two continents. Regional losses are much sharper: the southeastern subspecies has fallen 82% since 1940.

Which raptor conservation group launched the American Kestrel Partnership in 2012 to study why the bird is declining?

The Peregrine Fund recruited more than 2,400 birders, scientists, teachers and students. Together they logged over 60,000 observations of kestrel breeding activity.

Which 1918 US law makes it illegal to keep an American kestrel without a permit, such as a falconry license?

Migratory Bird Treaty Act rules protect native raptors, and permits are likewise required in Canada and Mexico. Licensed falconers often start out with a kestrel.

Which bird, brought to North America by people, now competes with American kestrels for scarce nesting cavities?

European starling numbers add pressure on a limited supply of nest holes. Researchers suspect several causes behind the kestrel's decline, including habitat loss and pesticides.

Which mid-sized North American raptor is notorious for boldly attacking American kestrels flown by falconers?

Cooper's hawk is strong enough to carry a kestrel away. Falconers report often saving their bird by rushing in and scaring the bigger raptor into letting go.

What human activity in the 1700s and 1800s likely boosted American kestrel numbers?

Forest clearing for farms opened up the kind of hunting ground kestrels like best. Today the felling of standing dead trees hurts them by removing nest sites.

The southeastern American kestrel has declined sharply as farms replaced the sandhill forests of which tree?

Longleaf pine stands were turned into farm fields, taking away the old trunks whose cavities these kestrels nest in. The subspecies has fallen 82% since 1940.

The American kestrel is not closely related to Old World kestrels; which process gave them similar looks and habits?

Convergent evolution shaped both birds for the same job: catching small prey on the ground from a perch or a hover. DNA puts the American species closer to the falcons that are not kestrels.

The American kestrel's family, Falconidae, is made up of the falcons and which other group of raptors?

Caracaras share the family but live differently: they are more sedentary feeders and build their own nests, which falcons do not.

American kestrel chicks hatch feeble, downy and unable to sit up for five days, a condition biologists call what?

Altricial young depend wholly on their parents at first, yet kestrel chicks grow fast: they reach adult weight in about 16 days and fly at around a month old.

Which English naturalist painted the Carolina "little hawk" behind the American kestrel's first scientific description?

Mark Catesby described and illustrated the bird in a natural history of Carolina published between 1729 and 1732. The formal Latin name followed a generation later, drawn from his account.

What is usually different about the last egg a female American kestrel lays in a clutch of four to six?

It is paler than the rest, probably because the female is short of resources after laying the others. The earlier eggs are white with brown spots.

After female American kestrels claim the open winter fields, where do the males tend to settle?

Wooded areas are what is left for the males, because females appear to migrate south first and take the open territories. The split shows up in many southern parts of the range.

How does a male American kestrel advertise his breeding territory to rivals and to a possible mate?

Repeated climbs and dives, with a burst of sharp notes at the top of each rise, announce that the territory is taken. In migratory populations the males arrive before the females.

What do American kestrels often do to much larger hawks and eagles they meet during migration?

They harass them, despite being the smaller bird by far. In the breeding season kestrels go further and attack hawks that enter their territory.

On which Caribbean island do resident American kestrels come in two distinct color morphs, one light and one dark?

Cuba's resident kestrels come in two morphs: one with extra white on the face and a very light underside, the other with a dark rusty belly.

What can landowners put up, well before the breeding season, to attract a pair of American kestrels?

Nest boxes stand in for scarce natural cavities, and kestrels take to them readily. A guard on the pole keeps predators from raiding the eggs and young.