Western Screech Owl

The Western Screech Owl is a breed of small North American owls, very similar in appearance to their Eastern counterparts – the Eastern Screech Owl. These birds are widely spread and are common throughout their habitat. There have been many myths and legends related to these nocturnal creatures, since their strange hoots in the middle of the night are enough to inspire awe and eeriness in the minds of the listeners.

Western Screech Owl Scientific Classification

Animalia
Chordata
Aves
Strigiformes
Strigidae
Megascops
Megascops kennicottii

Western Screech Owl

Western Screech Owl

Physical Description: What Does a Western Screech Owl Look Like

Size: On an average, they measure about 22 cm (8.7 in), while their wingspan length is 55 cm (22 in).

Weight: They are not too heavy, with the adult owls weighing between 88 to 22 g, with the average weight being 143 g (5 oz).

Plumage/Feathers: A few varieties of morphs are found viz. Mexican, gray Pacific, brown Pacific, Mojave and Great Plains, with all of them having dark gray or brown plumage with streaks on the underparts.

Head: The head is large and roundish with ear tufts protruding out just above the eyes.

Eyes: The eyes are large and round, with a big black eyeball surrounded by a yellow ring.

Bills: The Bills are yellowish to dark, and resemble a sharp nose that has rendered a humanoid face to the bird.

Feet: The feet are large with streaked plumage patterns.

Sexual Dimorphism: The female western screech owls are larger than the males.

Lifespan

The Western Screech Owls usually live for 1-8 years in the wild. But the longest lifespan recorded in the wild is at least 13 years. However, in captivity (or as pets), their longevity is more. A pair of captive WSOs had been recorded to have lived to be 19 years of age.

Western Screech Owl Range

Western Screech Owl Range

Distribution & Habitat: Where do Western Screech Owls Live

The western screech owls dwell primarily in the tropical, subtropical and temperate mountainous forests of the USA, Canada, Mexico, El Salvador, Honduras, Nicaragua, Guatemala, and Costa Rica. They are also found in the countryside fields, gardens and parks, deserts, and shrub lands.

Classification of Species

Nine subspecies of the Western Screech Owl has been identified:

  1. Megascops kennicottii aikeni
  2. Megascops kennicottii bendirei
  3. Megascops kennicottii cardonensis
  4. Megascops kennicottii kennicottii
  5. Megascops kennicottii macfarlanei
  6. Megascops kennicottii suttoni
  7. Megascops kennicottii vinaceus
  8. Megascops kennicottii xantusi
  9. Megascops kennicottii yumanensis

Differences: The Western vs. the Eastern Screech Owls

The Western and the Eastern screech-owls were considered to be one and the same species until the 1980s because of the strange resemblance in their physical characteristics. However, they differ from each other by their voices. Unlike the easterners, the westerners wouldn’t emit a screech, but low-pitched whistles that speed up towards the end, described as a ‘bouncy double trill’. WSOs apparently recognize their own kind by sound.

Western Screech Owl Images

Western Screech Owl Images

Sounds and Calls: How Do they Communicate

The male owls would emit mellow, muted trills like “hoo-hoo”, especially during mating and nesting seasons. Primarily, this call indicates territorialism. There is also a secondary trilling call with rapid bursts. They also give out other different calls like a prolonged “cr-r-oo-oo-oo-oo” during greeting, or a sharp bark when excited.
[Recordings: Listen to the Western Screech Owl calls’ audios and clips here.]

Video: Western Screech Owl Calling

Behavior

Like most other owl species, the Western Screech-Owl is active during dusk, night, or near dawn. These nocturnal birds are almost blind in the sunlight, and their activities begin approximately 20-30 minutes after sundown. However, the subspecies that are found in the western parts of Washington are at times found to stay active on sunless, cloudy days. They mostly spend time on tree tops, but will also forage on the ground for worms. These birds do not migrate.

The western screech owl is an opportunistic predator, and would perch onto branches of trees, waiting patiently for an unsuspecting prey passing by, and once found, it wouldn’t take the time to swoop down upon it. They eat small preys on the spot, and carry away larger ones for later.

Western Screech Owl Pictures

Western Screech Owl Pictures

Western Screech Owls

Western Screech Owls

This creature has an excellent sense of sound and vision, and would locate the prey easily. These birds tend to exhibit aggressive behavior. They would even attack humans while defending a nest site, or capture large preys like grouse for feeding their young.

Although, at times, they also feel threatened, or are attacked by larger predators. In such cases, the owl is often seen standing erect, holding their ear-tufts up, slicking down their body feathers, and drawing the feathers around their beaks forward to scare away the predators. They would also squint their large eyes, and sway forward and backward to imitate the movement of a branch.

Reproduction and Life Cycle

The WSO is monogamous by nature. They would pair before breeding season, and would engage in long-term bonds. Before mating, the male and the female will perch on a branch, sitting close to each other. The male would emit a mating call, which is usually reciprocated by the female.

These birds are secondary cavity nesters, and would make their nests in natural cavities, or those made and deserted by Northern Flickers or Pileated Woodpeckers at the height of 5 to 30 feet from ground level. They would also choose nest boxes, or cactuses for the purpose. They prefer to breed in open woods, or mixed woods at the edge of the forest.

Western Screech Owl Nest

Western Screech Owl Nest

Babies Western Screech Owl

Babies Western Screech Owl

Video: Family of Western Screech Owls in the Nest

Typically, a pair would hatch a single brood per year. The female would lay its eggs inside the nest-hole without adding any material to it. The clutch size is 3-5. The incubation period of the mother owl is around 33-34 days. During this time, the father owl would bring food to feed the female.

As the hatchlings break out, the mother would brood for about three weeks, while it is the duty of the father brings food to gather food for the mother and the fledglings. After about a week or 10 days, the young owlets learn to leave their nest cavity and explore the nearby trees. The juveniles do not go far from their nest for a few nights until they attain the ability to fly. The parents keep an eye on the baby owls for about five weeks, when they learn to fly for the first time.

Western Screech Owl Size

Western Screech Owl Size

Adaptations

  1. The tips of the western screech owls’ flight feathers are serrated for which the noise made by their wings during flying are muffled, allowing them to glide down silently on their unsuspecting prey.
  2. Since they live in the dense woods, they have developed an acute sense of hearing, which helps them trace mammals even under heavy vegetation or under thick layers of snow during wintertime.
  3. They have developed large eyes with an excellent power of vision, helping them pick up even small movements at night. This helps them locate both their prey and predators quickly.
  4. Their cryptic coloration helps them blend with the tree branch they have perched on. This predator evasion technique is called ‘tree branch mimic’, and is a kind of natural camouflage.
Blind Western Screech Owl

Blind Western Screech Owl

Diet: What Does a Western Screech Owl Eat

The WSO has an extremely wide range of prey species in its diet list, starting from small insects to even mammals that are larger to them by size. Though they mostly feast upon small mammals, they would also consume fish, amphibians, reptiles, birds, and invertebrates. The most favorite creatures in their dinner menu include small microtine rodents, deer mice, rats, small birds, large insects, depending on availability. Occasionally, they have also been known to hunt Mallard ducks and cottontail rabbits, and fledglings of local birds.

Western Screech Owl Bird

Western Screech Owl Bird

Video: Western Screech Owl Preying

Predators: What Eats the Western Screech Owl

Their most common enemies include cats, minks, weasels, raccoons, skunks, snakes, and other birds. The chicks are the more common targets to the predators.

Conservation Status

Considering their population abundance, the IUCN 3.1 has categorized them under ‘Least Concerned’.

Western Screech Owl Flying

Western Screech Owl Flying

Western Screech Owl Feather

Western Screech Owl Feather

Interesting Facts

  • They are the smallest owls found in North America.
  • The WSO has been scientifically named – Megascops kennicottii – after the American naturalist Robert Kennicott.
  • This breed is a close relative of the Scops Owl.
  • The Northern populations are noticeably larger than their Southern counterparts.
  • Notwithstanding their names, Western screech owls rarely emit screeching sounds.
  • The mortality rate in baby WSOs is as high as 70%, mostly because they are frequently hit by cars while hunting in the night.
  • Zeus is a rescued, blind Western Screech Owl that lives at the Wildlife Learning Center, Sylmar, California. The bird has become famous because its eyes resemble the starry night sky with twinkling galaxies.

Baby Western Screech Owl Video

References:

http://www.audubon.org/field-guide/bird/western-screech-owl

http://www.seattleaudubon.org/birdweb/bird/western_screech-owl

http://eol.org/pages/1025101/details

https://www.allaboutbirds.org/guide/Western_Screech-Owl/id

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