Western Screech-owl
While we're on the subject of owls, perhaps my favorite group of birds, I'd like to introduce you to a common little owl found across much of California and the west: the Western Screech-owl (Megascops kennicottii).
While I've heard and even seen these little nocturnal hunters right here in our Central Valley neighborhood, the following photographs were taken this past summer while Eric and I were birding in Southeastern Arizona at the fabulous San Pedro House near Sierra Vista.
Western Screech-owls inhabit open woodlands and forested areas below 6,000 feet in elevation, particularly favoring deciduous trees along rivers and canyon bottoms. But they are not uncommonly found in parks and suburban areas as well, where a reliable food source and suitable nesting habitat are to be found.
Screech-owls nest and roost in natural cavities, such as those excavated by woodpeckers or formed where branches break off of the trunk (as pictured here). They also readily take to man-made nest boxes. If you live in suitable screech-owl habitat (check their range map or look for recent sightings in your area), consider putting up a nest box. Plans are available online to build a nest box, or you may buy one instead.
The diminutive size of the Western Screech-owl, topping out around 8 or 9 inches from head to tail and weighing less than half a pound, belies its reputation as a fierce predator. They are entirely carnivorous, and small mammals, such as mice, shrews, woodrats, kangaroo rats and bats, make up a large part of their diet. However, their diet is diverse and varies with season and location. Given the opportunity, they will also prey on birds, fish, reptiles, amphibians and invertebrates, including insects, worms, slugs, and snails. (I once found a pile of empty snail shells, along with whitewash, beneath our backyard owl's perch!) Screech-owls generally utilize the sit-and-wait method of hunting, waiting quietly for prey to happen past them before swooping down to snatch it up, but will also catch flying insects or bats in midair. These tiny tyrants have even been known to take animals larger than themselves, like rabbits.
The name "screech-owl" is a bit of a misnomer. As I often tell people, screech-owls don't screech, Barn Owls screech! The song of the Western Screech-owl is often likened to a bouncing ball: a series of short whistled hoots that speed up toward the end. In contrast, the Eastern Screech-owl "whinnies" and the Whiskered Screech-owl toots in Morse code.
Learning the songs and calls of nocturnal birds, like owls and nightjars, is sometimes the only way to discern their presence or identify them. In addition to being active after dark, Western Screech-owls have another line of defense against being detected and disturbed in daylight hours: excellent camouflage.
The mottled grays and browns of their plumage blend seamlessly into a background of bark and branches. Perched against the trunk of a tree, the form of a quiet screech-owl melts into the pattern of bark. When alert, screech-owls elongate their bodies, raise their ear tufts, and look for all the world like just another snag or branch on the tree. I've had the privilege of working with these little owls in a rehabilitation situation, and have been able to examine their beautiful feathers up close. Never before have I seen something that mimics the colors, patterns, and textures of bark so flawlessly, so intricately. Their feathers are truly a work of art.
Though Western Screech-owls are nocturnal, spending daylight hours inside their roost or nest hole, they are sometimes seen sitting at the entrance of their hole, basking in the sun. This is how you are most likely to glimpse one of these beautiful owls during the day. But even that can present a challenge!
Can you spot the owl in the photo below?
Look closer at the hole three-quarters of the way up the left trunk. Here is the zoomed-in version:
For more information about North America's owls, including our little screech-owls, I recommend Peterson Reference Guide to Owls of North America and the Caribbean as well as Field Guide to Owls of California and the West.
But of course there are many excellent books on owls to choose from! Some on my wish list include:
Owls of the United States and Canada: A Complete Guide to Their Biology and Behavior
North American Owls: Journey Through a Shadowed World
Owls of North America
While I've heard and even seen these little nocturnal hunters right here in our Central Valley neighborhood, the following photographs were taken this past summer while Eric and I were birding in Southeastern Arizona at the fabulous San Pedro House near Sierra Vista.
Western Screech-owls inhabit open woodlands and forested areas below 6,000 feet in elevation, particularly favoring deciduous trees along rivers and canyon bottoms. But they are not uncommonly found in parks and suburban areas as well, where a reliable food source and suitable nesting habitat are to be found.
Screech-owls nest and roost in natural cavities, such as those excavated by woodpeckers or formed where branches break off of the trunk (as pictured here). They also readily take to man-made nest boxes. If you live in suitable screech-owl habitat (check their range map or look for recent sightings in your area), consider putting up a nest box. Plans are available online to build a nest box, or you may buy one instead.
The diminutive size of the Western Screech-owl, topping out around 8 or 9 inches from head to tail and weighing less than half a pound, belies its reputation as a fierce predator. They are entirely carnivorous, and small mammals, such as mice, shrews, woodrats, kangaroo rats and bats, make up a large part of their diet. However, their diet is diverse and varies with season and location. Given the opportunity, they will also prey on birds, fish, reptiles, amphibians and invertebrates, including insects, worms, slugs, and snails. (I once found a pile of empty snail shells, along with whitewash, beneath our backyard owl's perch!) Screech-owls generally utilize the sit-and-wait method of hunting, waiting quietly for prey to happen past them before swooping down to snatch it up, but will also catch flying insects or bats in midair. These tiny tyrants have even been known to take animals larger than themselves, like rabbits.
The name "screech-owl" is a bit of a misnomer. As I often tell people, screech-owls don't screech, Barn Owls screech! The song of the Western Screech-owl is often likened to a bouncing ball: a series of short whistled hoots that speed up toward the end. In contrast, the Eastern Screech-owl "whinnies" and the Whiskered Screech-owl toots in Morse code.
Learning the songs and calls of nocturnal birds, like owls and nightjars, is sometimes the only way to discern their presence or identify them. In addition to being active after dark, Western Screech-owls have another line of defense against being detected and disturbed in daylight hours: excellent camouflage.
The mottled grays and browns of their plumage blend seamlessly into a background of bark and branches. Perched against the trunk of a tree, the form of a quiet screech-owl melts into the pattern of bark. When alert, screech-owls elongate their bodies, raise their ear tufts, and look for all the world like just another snag or branch on the tree. I've had the privilege of working with these little owls in a rehabilitation situation, and have been able to examine their beautiful feathers up close. Never before have I seen something that mimics the colors, patterns, and textures of bark so flawlessly, so intricately. Their feathers are truly a work of art.
Though Western Screech-owls are nocturnal, spending daylight hours inside their roost or nest hole, they are sometimes seen sitting at the entrance of their hole, basking in the sun. This is how you are most likely to glimpse one of these beautiful owls during the day. But even that can present a challenge!
Can you spot the owl in the photo below?
Look closer at the hole three-quarters of the way up the left trunk. Here is the zoomed-in version:
For more information about North America's owls, including our little screech-owls, I recommend Peterson Reference Guide to Owls of North America and the Caribbean as well as Field Guide to Owls of California and the West.
But of course there are many excellent books on owls to choose from! Some on my wish list include:
Owls of the United States and Canada: A Complete Guide to Their Biology and Behavior
North American Owls: Journey Through a Shadowed World
Owls of North America
 |
| This Western Screech-owl was injured and is unable to survive in the wild, so he now lives a comfortable life at the Stanislaus Wildlife Care Center where he works as an animal ambassador, educating school kids and the public about our local wildlife. |
Comments
Post a Comment