Reflections in Nature:Kestrel is Pa.’s smallest falcon

I was watching a kestrel sitting on a power line when all of a sudden it dropped into the grassy field beneath. Within a few minutes, the kestrel took flight and, with the sun shining on its rust-colored back, his slate-blue wings brought him back to the power line.

Evidently, the kestrel’s prey escaped, for its talons were not holding anything.

The kestrel once was known as the sparrow hawk, which was in reference to its killing sparrows; however, the kestrel is not a hawk but a falcon, and sparrows are only a small part of its food.

During the summer months when insects are abundant, its diet is made up of grasshoppers, crickets and other small insects. During the winter months, they prey mainly on mice and small birds.

The kestrel’s scientific name is Falco sparverius. The genus name Falco is Latin and means “hawk,” which refers to the hooked shape of the claws. The species name sparverius comes from the Latin espervier, meaning “sparrow hawk,” which was this bird’s original name.

The common name kestrel is thought to come from the Latin word crepitare, meaning “to rattle or crackle,” which describes the kind of call emitted by the kestrel.

The kestrel is the smallest falcon in North America, while the sharp-shinned hawk is the smallest hawk.

The kestrel is designated a falcon because of its long, pointed wings; round head and the black moustache and sideburns that are found on its larger cousins, the peregrine and the merlin (originally called the pigeon hawk).

Although falcons do resemble hawks, the outward appearance of our falcon family is their toothed and notched bills, short necks, long pointed wings and rather short to medium tapered tails.

To ornithologists, a true falcon, whether male or female, is referred to as a falcon; however, in falconry terms, the female is the falcon and the male is the tiercel or terrel (based on the old belief that every third bird in a nest is a male or that the male is about one-third the size of the female.

Throughout the middle of the day, a kestrel can be seen while perched on a wire. Kestrels hunt mostly in the mornings and late afternoons.

The kestrels are one of only a few flying predators that are able to hover in mid-air. When prey is seen, the kestrel will partly fold its wings, drop lower and then swoop to the ground, hoping to catch a meal.

The kestrel is one of our falcons that is able to live in desert areas since the moisture needed comes from its carnivorous diet, which frees it from dependence of water.

The kestrels of Canada and Northern United States migrate as far as Central America and the Caribbean. The peak of the fall migration is from mid-August through mid-October, and the peak spring migration occurs in mid-March through April.

Although kestrels are seen in Pennsylvania during the winter months, they are absent from the northern counties.

Kestrels are cavity nesters, nesting in hollow trees and houses built for them. The female does not build much of a nest, if any, and often lays her four to five eggs on the bare floor of a nesting box.

Although none of the true falcons seem to build their own nests, they sometimes improve on existing nests.

The female does most of the incubation, which takes 29 to 30 days. When the male calls to the female, she flies out of the nest for the male to feed her. The young will leave the nest 30 to 31 days after hatching.

The other falcon that might be confused with the kestrel is the merlin, which is not common in Pennsylvania but does migrate through the state. Most of the merlin population is found in the southeastern part of the state and in counties near Lake Erie.

The merlin’s scientific name is Falco columbarius. Falco is Latin and means “hawk,” referring to the hooked shape of the claws; the species name columbarius pertains to doves. The merlin once was known as the pigeon hawk, due to its killing pigeons.

Our largest falcon is the peregrine. Its scientific name is Falco peregrines. The species name is Latin and means “alien, that which comes from foreign parts; wandering.” The name comes from their long-distance migrations.

In Canada, one peregrine banded in July 1965 was shot and killed six months later in Argentina.

Peregrines once were known as duck hawks because of their ability to kill waterfowl. A peregrine falcon can reach speeds of over 200 mph in its power dive, which is called a stoop by falconers.

Hawks and falcons were one of the first means for man to capture and kill game. Pennsylvania still has a season for falconers to participate in this ancient sport.

Bower retired after 34 years as a wildlife conservation officer for the state Game Commission. He has published several books about his experiences. Questions and comments may be sent to him at 153 Redington Ave., Troy PA 16947.