Seven species of one of the more mysterious and, at times, misunderstood group of birds, the owls, make Pennsylvania their home as breeding birds. An eighth species is a nearly annual vagrant from the Arctic. Most are nocturnal- active at night. These are among the most appealing birds in the state and an inspiration to explore Penn’s Woods and learn more about birds. A wonderful way for people to connect to nature. Birders can challenge themselves by adding more owl reports to eBird and other surveys. These charismatic birds of the night inspire a great deal of interest by the public in birds and nature. Birders of Pennsylvania are fortunate that our state has so many owl species and many opportunities to enjoy them. Owls can be found even after their nesting season since the young can be vocal and some species announce themselves once the brooding season is over.
It’s December and at dusk a deer hunter ending a day’s hunt hears in the distance familiar hooting. One call is distinctly higher pitched than the other. It’s a pair of Great Horned Owls setting up their territory at the beginning of their breeding season. During an early spring night a homeowner living next to a woodlot hears an unusual repetitive tooting sound not unlike a car’s backup alarm- a Northern Saw-whet Owl announcing winter’s end. In the late summer and early autumn, many of us living in rural and suburban areas have listened to the rather bizarre “whinny-bounce” call of the Eastern Screech Owl and the tell-tale deep hoots of the Barred Owl.
All owls are predators with exceptional hearing and superb binocular night vision. They are rigged for silent flight thanks to the softened leading edges of their flight feathers. These hunters possess powerful, sharp talons for grasping prey and bills capable of rendering a swift kill.
Owls produce pellets which are regurgitated indigestible food materials- hair, feathers, bone, and nails. Because their eyes are fixed in their skulls, owls can move their heads in an arc of about three quarters of a circle or 270 degrees. Owls do not build nests. They use primarily hawk and crow nests and sometimes cavities.
Perhaps the most well known of Pennsylvania’s owls is also our largest- the Great Horned Owl. It is one of the state’s earliest nesting birds, with adults on eggs as early as January. They produce the familiar hoo-hoohoo hoo hoo call that almost sounds like Morse code. Great Horned Owls are fairly common throughout the state. Weighing in at over three pounds and up to 23 inches in length with noticeable ear tufts, this is out largest resident owl. During the early twentieth century, these owls were considered vermin and had a bounty placed on them to encourage killing them.
Great Horned Owls are the most aggressive and powerful bird in North America- so much so that they have been known to displace and even kill Bald Eagles and attack people getting too close to nests. Their diverse diet consists of a wide variety of birds and mammals. They are nocturnal, but often begin their courtship hooting about a half-hour before sundown in winter months. Wherever there are sufficient numbers of large trees, these birds can reside in a variety of habitats including large forest tracts, residential areas, parks, and woodlots. They often hunt in more open areas often using poles as hunting posts, making it easier to spot them in dim light.
The Barred Owl is Pennsylvania’s second largest resident owl at 21 inches in length and about two pounds. They have no ear tufts and completely dark eyes. Prey animals include small mammals and birds, amphibians, and even fish. These owls are generally nocturnal but can be vocal and active during early mornings and cloudy afternoons and are often seen perched during the day.
They are rather common throughout Pennsylvania and usually found in mature forested areas, both dry and swampy. Occasionally Barred Owls turn up in farmland and urban areas. The most familiar Barred Owl vocalization of hoots is the “Who cooks for you, who cooks for you all?” call. However, they have quite a repertoire of sounds including a hair- raising scream. Barred Owls usually nest in tree cavities but have been known to use hawk, crow, and squirrel nests.
Eastern Screech Owls are a small owl with ear tufts about 10 inches long and weighing about one half pound. They are found in two color phases- a more common gray form and a less common reddish form. There is also a rarer intergrade form described as a muddy brown color. Interestingly, individual broods can consist of more than one color phase. The vocalization of the screech Owl is a sort of trembling wail, often called a “whinny-bounce” call.
Screech-owls are tree cavity nesters, occasionally using nest boxes and are nocturnal. These owls are common and widespread in Pennsylvania. Their diet consists of small mammals, small birds, amphibians, and a variety of invertebrates. Their choice of habitats is diverse. They reside in forested areas, residential areas, parks, orchards, and small woodlots. Some screech-owls can become habituated to humans and will hunt in backyards without paying any attention to the people watching them. Screech-owls will nest in boxes designed for Wood Ducks that are place along streams, in woods, or park-like settings.
At a length of eight inches and between 2.5 and 4 ounces in weight, Pennsylvania’s smallest owl is the Northern Saw-whet Owl. This little owl has no ear tufts. Once thought to be uncommon, surveys in recent years have shown this owl to be much more common breeding bird in forested areas than previously realized. It’s breeding range in the state is primarily in forests of higher elevations and the northern tier. Their breeding range extends south to the Mason-Dixon line in the mountain forests. It is also one of a few owls in Pennsylvania which are migratory. The majority of this owl’s autumn migration occurs in October and November, with a more limited northward spring movement in February and March.
Saw-whet Owls are found in forested areas, thick shrubby habitats, conifer stands, and coniferous wetlands. They are strictly nocturnal and utilize heavy vegetation for concealment during the day. Nests are primarily in tree cavities, however, they will occasionally use nest boxes. Prey consists of small rodents and other small mammals, bats, small birds, amphibians, and insects. Their main vocalization is a repetitive whistle-like toot that sounds a bit like a truck backing up. The owl’s name comes from another of its vocalizations which is similar to the sound of a saw being sharpened with a file.
Looking much like a smaller version of a Great Horned Owl, the Long-eared Owl is listed as threatened in Pennsylvania. It is about 16 inches long and weighs just under three quarters of a pound with prominent ear tufts. The vocalization is usually a series of three hoots. A variety of other sounds are produced at times. They are strictly nocturnal. Prey consists of small mammals and birds, amphibians, and insects. Long-eared Owls are exceptional rodent hunters. It is imporant to follow the basic principles of good birding ethics when watching Long-eared Owls and other owls at their roost and nests.
Only a few nest sites have been documented- most recently, a very few from the central and southcentral regions. Hawk or crow nests are used by them, usually in conifers. During the winter Long-eared Owls usually roost in groups, anywhere from two to over twenty birds. Nesting sometimes results at a winter roost site when a pair remains there in the spring. Their preferred habitat is heavy conifer stands near open areas for hunting and often with bodies of water nearby.
The Short-eared Owl is listed as endangered in Pennsylvania. Nest sites have been limited to a very few in central and western Pennsylvania on strip mine reclamation areas. Their nests are on the ground, hidden in grassy areas or shrubs. Short-eared Owls are open country birds, preferring grasslands, lakeshores, and occasionally wetlands. They share the same habitat as Northern Harriers in the daytime. These owls tend to be most active at dusk and dawn. Such activity is known as crepuscular. However, it is not unusual for them to be active during late afternoons.
Short-eared Owls sometimes vocalize using high pitched barks and occasionally hoots. They feed on small mammals and birds. Their length is between 13 and 16 inches and weighing just under one pound. They are a migratory owl, with larger numbers migrating into the state in the fall and wintering over until February or March. It is not unusual for some wintering birds to roost in trees and shrubs. For more about the Long-eared and Short-eared Owls, please check the Endangered species section of the PGC’s website.
The nocturnal Barn Owl is a light colored owl with long legs and a heart- shaped face. It weighs in at just over one pound and is 15- 20 inches in length. It’s nickname is the monkey-faced owl. The calls of the Barn Owl are unusual, consisting of mostly screams and hisses. It is a prolific hunter of rodents and is considered to be one of nature’s best rodent controls. They also feed on small birds, other small mammals, and insects.
This owl nests in barns, silos, old buildings, belfries, and tree cavities. If prey is sufficiently plentiful, broods can be large- as many as eleven eggs in one nest. The result of large broods of Barn Owls is that considerable numbers of rodents can be taken- in the thousands in just one breeding season.
An owl that has been in serious decline for years in Pennsylvania, the Barn Owl has been the subject of a major restoration effort by the Pennsylvania Game Commission in conjunction with landowners. An owl of open country, farmland, and large wetlands, the Barn Owl has too long and too often been a victim of loss of habitat and nesting sites, and the toxic effects of pesticides and rodenticides.
Barn Owl nesting locations currently are restricted to primarily the southcentral and southeastern areas of the state, with a few locations in the northcentral region. The PGC’s Barn Owl Recovery Project involving placements of man made nest boxes in appropriate habitat with cooperation of landowners along with educating the public has helped to increase the numbers of nest sites and overall knowledge and appreciation of the barn owl, the “farmer’s friend” and champion mouser.
The last species of owl discussed here is a winter visitor from the Arctic, occurring almost annually in Pennsylvania- the Snowy Owl. Nesting from northern Alaska, across Arctic Canada to Labrador, this large whitish owl is an irregular visitor to the state. Snowy Owls can arrive here as early as late October and stay as late as mid May. They prefer exclusively open habitat such as farmland, lakeshores, airports, and urban areas. Shopping malls, industrial parks, and prisons, although unusual, have been used by them. The diet of Snowy Owls consists of a variety of small mammals and birds, including waterfowl.
Most of the Snowy Owls that visit Pennsylvania are immature birds. Previously it was thought they come south from lack of food in the north. The historic irruption of Snowy Owls that occurred during the winter of 2013- 2014 revealed that the large number of owls (200- 300) which came into the state was actually the result of an exceptionally successful breeding season in the Canadian Arctic during the spring of 2013.
Broods of Snowy Owl were large in response to huge numbers of lemmings, the primary food source. Most young owls survived and consequently were forced out of their nesting territory, coming south into the eastern United States as a response. More information on this event can be found at: www.projectsnowstorm.org. The PGC supports the research conducted on owls with Project SNOWstorm.