Tuesday, April 23, 2024

A screech owl has large yellow eyes, a yellow beak, white eyebrows, and tufts of hair that resemble ears. (Photo: Ann Schlesinger)

According to the aristocratic British writer Lady Mary Wortley Montagu and her poem “The Politicians,” written sometime in the 1700s,

The screech-owl, with ill-boding cry,
Portends strange things, old women say,
Stops ev’ry fool that passes by,
And frights the schoolboy from his play.

Do screech owls (Megascops asio) actually screech? To many people, the sound is more like the whinnying of a horse, and sometimes a low, monotone trilling sound. John James Audubon described the sound this way in 1832:

The notes of this Owl are uttered in a tremulous, doleful manner, and somewhat resemble the chattering of the teeth of a person under the influence of extreme cold, although much louder. They are heard at a distance of several hundred yards, and by some people are thought to be of ominous import.

However you describe the sounds, one thing is certain: You are more likely to hear this owl than see it, because these owls are active at night and blend in well with their environment during the day, when they sleep.

Eastern screech owls have two color variations: They are usually either reddish-brown (rufous) or grayish. (Photo: Joel Weber)

There are 510 species of birds in Massachusetts, a dozen of which are owls. The second-smallest owl in Massachusetts is the Eastern screech owl, only about 8 or 9 inches from head to foot. Screech owls have pointed tufts on the tops of their heads, and although the tufts may look like ears, they are nothing more than feathers. Instead they have ear openings on each side of the head, one higher on the head than the other to help the bird better pinpoint prey in the dark.

Screech owls have complex banded and spotted patterns that camouflage them when they perch in trees. (Photo: Richard George)

Screech owls also have exceptional eyesight in darkness and in light, and night vision requires large corneas that can collect light even in the dark. It’s why most nocturnal animals have large eyes. But owls also have small skulls, so their eyes evolved into a cylindrical or rod shape. (Some deep-sea fish also have rod-shaped eyes for seeing in the dark.)

Since their eyes are not round, owls cannot move their eyes in the sockets the way humans do, and therefore must turn their entire head to look in another direction. To help with this feat, owls have 14 vertebrae in their necks (humans have seven). These extra vertebrae allow owls to spin their heads 270 degrees, three-quarters of the way around.

A screech owl, asleep in Huron Village. (Photo: Richard George)

Unlike most owls, which look for food while resting on a tree branch, screech owls fly while hunting. When they spot prey, they quickly and quietly fly down and grab it with their talons, then fly up into a tree and tear their prey apart to eat it. Screech owls have one of the most varied diets of any North American owl – almost anything smaller than they are. They will eat small birds and mice, shrews and grasshoppers, snakes and earthworms, salamanders and frogs, as well as moths and other insects if it is the right time of the year. But because they are so small, they are preyed upon by other larger owls, such as barred owls and great horned owls. They also die from eating poisoned rodents and from being hit by cars – because screech owls chase moths that are attracted to street lights, it is not uncommon for these owls to get hit by cars at night.

A screech owl surveys the scene at Fresh Pond. They make many sounds, including whinnies, trills, moans, rattles … and screeches. (Photo: Kim Starbuck)

Eastern screech owls are found in forests throughout the state, but are more common in lower elevations in the east and not found in the high-elevation forests of the Berkshires. Screech owls do not migrate, but maintain a home range during the winter; in severe weather, they might need to move from their home range to search for food. Eastern screech owls do not build nests but rather lay their eggs in existing tree cavities. They also will use nest boxes, which you can build and mount on a tree or pole in a yard.

A screech owl sleeps in a tree cavity in Somerville. (Photo: Joel Weber)

These birds mate for life and lay four to five eggs in late March through mid-April. After about four to five weeks, the young leave the nest, but owl families often remain near each other throughout the summer. In August and September, the youngsters begin calling; you may hear their nighttime cries, which in the past people thought were frightening. Even Henry David Thoreau, who waxed poetic about so many creatures in nature, had this to say about these tiny birds:

I love to hear their wailing, their doleful responses, trilled along the woodside; reminding me sometimes of music and singing birds; as if it were the dark and tearful side of music, the regrets and sighs that would fain be sung … Oh-o-o-o-o that I never had been bor-r-r-r-n! sighs one on this side of the pond, and circles with the restlessness of despair to some new perch on the gray oaks. Then – that I never had been bor-r-r-r-n! echoes another on the farther side with tremulous sincerity, and – bor-r-r-r-n! comes faintly from far in the Lincoln woods.


Seen nearby

A white domestic goose joins a flock of Canada geese near the Charles River in Cambridge on Oct. 19. (Video: Gaelin Kingston)


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Jeanine Farley is an educational writer who has lived in the Boston area for more than 30 years. She enjoys taking photos of our urban wild things.