Eastern Screech Owl

STATUSLeast Concern

COMMON NAME (SCIENTIFIC NAME)Otus asio

DIETInsects, mammals, reptiles, amphibians, and even other birds

RANGEEastern part of North America from the bottom of Canada to the top of Mexico

HABITATReadily adapt to living near humans, prefer to be located in wooded regions

Eastern Screech Owl

The Eastern screech owl has an average body length of 16-25cm, a wingspan of 48-61cm, and weighs 121-244 grams. As is common with many birds of prey, the females of this species tend to be larger than the males. Eastern screech owls have also been known as Common screech owl, Little Owl, Scritch Owl, Little Horned Owl, Little Grey Owl, and Red Owl.

Eastern screech owls can be found in two distinct color morphs: gray and rufous (a red/brown coloration). Recently a third less distinct brown color morph has been recognized. All of these morphs have darker streaking of color covering the body and allow the bird to easily blend in with tree bark in their habitat. Eastern screech owls have feathered tufts on their heads and feathered feet as well. Juveniles of the species closely resemble adults, but have ear tufts that are not fully developed and may also have light and dark barring on the head, mantle, and under parts.

The two most common calls of the eastern screech owl are the even-pitched trill and the descending whinny. Both of these calls can be heard at night as this animal is primarily a nocturnal hunter.

Related To:
Western screech owls, great horned owls, barred owls

Habitat/Range:  Due to their ability to easily adjust to many habitat types, the eastern screech owl has a large ecological niche. They can readily adapt to living near humans in urban and suburban areas, although they prefer to be located in wooded regions. Being cavity nesters, they easily accept bird boxes as a nesting site. These small owls can be found all along the eastern part of North America from the bottom of Canada to the top of Mexico. Eastern screech-owls are not migratory birds.

Diet in Wild:  Eastern screech-owls in the wild have a greatly varied diet. They catch and eat most things smaller than them including insects, mammals, reptiles, amphibians, and even other birds. These amazing little owls are even agile enough in flight to prey on finches, jays, and doves among other birds. They have also been known to eat the occasional bat, frog, tadpole or lizard. When it comes to mammals, screech-owls frequently consume rats and mice as well as moles and rabbits. If an eastern screech-owl catches more food than it can eat, it may cache excess food in tree cavities to save for other days when hunting isn’t as successful.

These owls have symmetrical ears, which suggest that they hunt primarily using their vision.  They do, however, have excellent hearing as they often capture prey hidden by leaf litter.  They hunt by sitting on a tree branch and waiting to see or hear prey. (http://animaldiversity.ummz.umich.edu/accounts/Otus_asio/)

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:  In the wild adult eastern screech-owls natural predators included larger owls (such as the great horned owls), hawks, and on occasion even other eastern screech-owls. These birds are also in danger of being struck by vehicles as they hunt along road ways.

As eggs and nestlings, the list of predators increases. Many animals such as snakes, opossums, and raccoons may raid nests to eat eggs or juvenile birds.

Life Cycle And Social Structures: Once they’ve reached sexual maturity at about 1 year of age, eastern screech-owls will select a mate and pair bond to that bird.  Like many birds of prey, most eastern screech-owls mate for life after successful breeding. This means that if a pair is not successful at nesting or raising young, they may switch and pair with other birds. Once they are successful, pairs tend to stay together. On occasion one male may nest with more than one female in a season. To court a female, the male screech-owl will give a trill call while running up and down branches. Once mated, the female will select a nest location.

Eastern screech-owls do not build nests and thus must find already made nest cavities to occupy. They will use anything from woodpecker holes to nest boxes meant for wood ducks and kestrels. The female will settle into what ever debris is in the bottom of her nest and create a depression in which to lay her eggs. Breeding season occurs at the end of February into early march.

Eastern screech-owl females lay eggs over a period of days to more than a week and generally do not begin full-time incubation until the last egg is laid.  As a result, eggs laid first also develop and hatch first.  With larger broods, where newly hatched young may be developmentally up to 8 days behind their nestmates, younger nestlings tend to be killed accidentally or eaten by their larger siblings.  Screech owls lay from 2 to 7 eggs, usually 3 or 4, in a large nest cavity.  (http://animaldiversity.ummz.umich.edu/accounts/Otus_asio/#reproduction)

After hatching, young stay in the nest for 28 days. After this they will leave the nest but remain with the parents until they reach 8 to 10 weeks of age.

These owls are solitary during most of the year except during breeding and winters where mates share nests together.

Life Span:  Wild screech-owls can live for up to 14 years although in captivity these birds have been known to live between 20 and 30 years.  

Interesting Facts:

  • Screech owls do most of their hunting during the first 4 hours after sunset.
  • Like most owls, eastern screech owls have flight feathers that have soft edges so air rushing through them doesn’t create sound.
  • The disc feathers around the eyes serve as sound collectors. Wide set ear tufts can stand up totally when alert or lay flat against head to help funnel sounds into ear slits which are located on the sides of the head.
  • Owls regurgitate pellets (castings) of feathers, bones and fur several hours after they’ve eaten. It’s believed that pellet formation and regurgitation are necessary for a bird’s good health.
  • The screech owl’s eyes are fixed in their sockets. Special muscles in their necks allow them to rotate their neck up to 260 degrees so they can see the area around them.

Conservation Message:  Screech owls like other birds of prey are very important predators.  Screech owls usually consume insects and small rodents which humans consider harmful and pests. They are able to eat 25% of their body weight daily thus being beneficial to farmers as pest controllers.

 What You Can Do:
Do not litter. Birds of prey can be seen hunting along highways all over the country which is very dangerous for them, many of them are hit by cars or somehow injured along the roadways.  Birds of Prey are attracted to the roadways because their prey forages on the trash thrown out of cars that gathers along the roadside.  Everyone can make a positive impact by not littering or even volunteering to remove garbage from the roads.  Although many people may not consider apple cores or banana peels to be “litter”, it can still attract animals the roadside. Taking it home and disposing of it properly can help a bird of prey near you.

Adding a nest box is another way you can help the eastern screech owl. These owls are cavity nesters and will readily move into a manmade nest box. Eastern screech owls can be picky about where their nest box is placed and how big the hole to the box should be, so be sure to check with your local Audubon society or other bird group on the best way to make and place a nest box.

Bibliography
http://www.allaboutbirds.org/
http://animaldiversity.ummz.umich.edu/accounts/Otus_asio/