Mar 30, 2008

Of Hawks and Owls

They are both spectacular birds.  About the size of a blue jay or robin, one fills a niche by day that the other fills by night.  Kestrels and screech owls are easy observed birds that just about anyone can enjoy watching.


American Kestrels (Falco sparverius) are our smallest falcon and found across the continent.  Swift and erratic flyers, falcons are sleek raptors with pointed wings and narrow tails.  Birds of open country, kestrels are often seen hovering along the interstate and roadsides.  Frequently called sparrow hawks, they will sometimes eat sparrow-sized birds, though more frequently crickets, grasshoppers, snakes and mice.  It is easy to spy kestrels sitting on power lines and can be distinguished from other birds by their tail pumping.


Like many other bird species, male kestrels are more striking in appearance than the drabber female.  The handsome males are rufous above with blue-gray wings and a black and white-tipped rufous tail.  Females lack the striking gray wings.  Both sexes have the black and white moustachial stripes typical of falcons.  Like other birds of prey, females are larger than males. Nicknamed the killy hawk, kestrels emit a call of killy, killy, killy.  These sharp calls are signs of aggression and are heard when intruders are encountered.


Whereas kestrels are diurnal (active during the daytime), screech owls are nocturnal.  Screech owls do not screech; their call is more like a whinny.  Ironically, their larger cousins, barn owls, do screech.  Go figure.


Eastern Screech Owls (Otus asio) are the only small owl in the Eastern U.S. with ear tufts.  These beautiful owls come in two color phases, red and grey.  Both color phases are seen in Northern Kentucky, though the grey phase is most common.  Screech owls are found in wooded areas with mature trees.  They frequent woodlots, orchards, cemeteries and parks.  They are also frequently found in many of Northern Kentucky’s older subdivisions, though often overlooked because they are active only at night. 


As soon as the lights go out screech owls begin their hunting rounds.  They glide over open areas looking for mice, insects, snakes, toads and small birds.  They will snatch a bird at its roost site as it sleeps at night.  Sometimes though, the hunter can become the hunted.  The much larger great horned owl will frequently dine on screech owls. 


One way to detect owls is by finding their pellets.  Owls swallow their prey whole and several hours later regurgitate the inedible fur, feathers and bones as a compact pellet. 

Pellets litter the ground below favorite roost sites providing clues to roost locations and diet. 



Kestrels and screech owls are secondary cavity nesters, nesting in holes excavated by other birds or in naturally occurring cavities and fissures.  These birds suffer from a lack of suitable nest sites because of our propensity to take down the dead, hollowed trees they would normally use for nesting.  Both birds will readily use nest boxes though.  Northern Kentucky’s neighborhoods are more attractive to screech owls, whereas rural areas are favored haunts of kestrels.  Screech owls can frequently be seen peering from favorite nest/roost boxes year round.


Now is the perfect time to hang a nest box, as both species of birds are actively seeking nest sites.  Nesting begins in April.  Kestrels and screech owls both lay 4 to 5 eggs with incubation lasting a little less than a month.  Males of both species feed the female as she is on the nest and help feed the young after the eggs hatch.  A month after hatching, the young are ready for their first flight.


Kestrels and screech owls are fantastic birds and easily observed.  A nest box takes no more than an hour to build and, if properly constructed, will last a good 10 years.  Once you attract these birds, you realize your good return on investment.  They are a joy to watch.



If you would like plans for a kestrel/screech owl nest box sent to you, contact or

No comments: