Showing posts with label Barred Owl. Show all posts
Showing posts with label Barred Owl. Show all posts

Monday, April 13, 2015

Everglades Sampler

I am finally to the Everglades, a uniquely beautiful gem among our National Park system. Many of the birds introduced earlier in this extended blog series were also present in the Everglades. Here I give a sampling of birds not seen - or not photographed - previously in our south Florida travels.

A surprise sighting (and one noted by a naturalist in the Visitor's Center) was this Western Kingbird ...
Western Kingbird

Briefly we watched as 3 Swallow-tailed Kites soared and swooped overhead, a study of winged gracefulness, and one which I wish I could have seen more of ...

Swallow-tailed Kite

Alas, during our Florida travels we had only one encounter with a Roseate Spoonbill, but it was a treat ...
Roseate Spoonbill

The birds of prey were well into their nesting season. We saw Red-shouldered young not long out of the nest. In Flamingo, there were several Osprey nests which were active in incubating or feeding young ...

Osprey

... and on two occasions, nestling Barred Owls tipped off their presence by hooting for food. ...

Barred Owl (nestling)
Not feathered, but still fauna, were these deer ...

White-tailed Deer
And finally, while driving the keys, we stopped at The Laura Quinn Wild Bird Sanctuary, a funky and fascinating rehab center. High in a tree, a Great Horned Owl kept watch over the visitors ...

Great Horned Owl

Tuesday, December 13, 2011

Owls - Masters of the Night

Athenian tetradrachama, 5th cen. B.C.
Owls are birds of the night. Their nocturnal vigilance was often associated with the studious scholar or the wise elder and made them symbols of wisdom and learning. The Greek goddess of wisdom and learning was Athena; one of her symbols was the owl. The ancient coins of Athens  carried the image of an owl as a sign of the patron goddess who vigilantly watched over the city. The owl was the Little Owl; in an attempt to increase their wisdom, some ancient philosophers ate the Little Owl, hoping to introduce the owl’s attributes of intelligence into their own persons. But they did not know what part of the bird contained the wisdom, so they ate the whole thing.

Athena with Owl, Louvre
The association of the owl with wisdom and learning is still present in a few centers of learning. Temple University in Philadelphia terms itself the “Owls,” while the medieval-style buildings of nearby Bryn Mawr College are decorated with owls. In the corner of Bryn Mawr’s Great Hall, a statue of Athena and her owls receive offerings around exam time.

Owls have large, forward-facing eyes. When we do see a live owl, it appears alert. It surveys its realm with attention and vigilance. It looks intelligent. It looks “wise as an old owl.”

But are owls wise? One writer put it succinctly: “To put it kindly, owls are no wiser than they need to be, i.e., not very.”

Owls are wise enough not to “rotate their heads through 360 degrees as is commonly supposed and which would in the event result in owls heads coming clean off and bouncing about all over the place.” (owlpages.com ) Owls cannot rotate their eyes in their sockets and have compensated by developing extra vertebrae in their necks which allow them to turn their heads about 270 degrees. However, they rarely turn their heads more than 180 degrees. In other words, an owl can look to its left by turning its head to the right but prefers not to.

Owls are primarily night hunters and are superbly equipped for their task Their eyes and ears are adapted to finding prey in the dark. Their feathers are designed for silence. They are the stealth flyers of the bird world.

Owls cannot “see” in the dark. A dead mouse in a totally darkened room went undiscovered by a Barn Owl. But an owl can see in light levels so low that we would be rendered totally blind. Light is measured in “lux”. The lowest number of lux in which humans can see is 37,000. Experiments on a Tawny Owl revealed that the lowest number of lux at which it was able to see was seven!

Or, consider the ears: The ears are asymmetrically located in the skull. The right ear is higher than the left ear. The ear openings are differing shapes. This means that sound reaches each ear a split second apart, enabling the owl to “triangulate” the location of its prey, pinpointing a sound to within ten millimeters with no aid from sight whatsoever. The flat face of the owl, formed by feathers, acts like a satellite dish to capture and direct sound to the ears. Some owls are capable of finding prey by sound alone. An experiment put live mice in a totally darkened room with a Barn Owl. Using hearing alone, the Barn Owl caught the mice every single time.

Barred Owl
The most common owls in Vermont are both nocturnal hunters: Barred Owl and Great Horned Owl. The call of the Barred Owl can be heard throughout our eastern forests; it prefers heavily wooded swamps, hemlock or pine forests. On many occasions I have kayaked on Sunset Lake on a summer evening. Nearly every time I have heard the distinctive call of the Barred Owl: “Who cooks for you? Who cooks for you? Who cooks for you allll?” It is not uncommon to hear a duet from this very vocal owl.

Daytime sightings of the Barred Owl are uncommon, but not unusual. It happens most often in the winter when food may be scarce, or under deep snow cover, or both. A Barred Owl active during the day is a hungry owl. It may also be a young owl which did not have time to hone its hunting and survival skills before winter arrived to make the task of finding food even more difficult.

The Barred Owl is one of the few owls which will reveal itself to humans. In “The Atlas of Breeding Birds of Vermont,” 1985, the Barred Owl is described this way: “A gentle creature with an engaging personality, the Barred Owl can be quite tame and curious even in the wild. One individual raised at the Vermont Institute of Natural Science’s raptor care facility in Woodstock returned there each winter for four years after his release, greeting his former benefactors with hoots, and swooping down to pluck mice from their hands.”

Great Horned Owl
One will often hear expressed something akin to affection for the Barred Owl. Affection is rarely expressed toward the second most common owl in Vermont, the Great Horned Owl. What one hears in relation to the Great Horned Owl is awe. Edward Forbush begins his description of this species this way: “The Great Horned Owl is not only the most formidable in appearance of all our owls, but it is the most powerful. The Great Gray Owl and the Snowy Owl may appear larger, but the Great Horned Owl exceeds them in courage, weight, and strength. Indeed, it little regards the size of its victim, for it strikes down geese and turkeys many times its weight, and has even been said at times to drive the Bald Eagle away from its aery and domicile its own family therein.”

Great Horned Owl - John James Audiubon
The Great Horned Owl (its “horns,” are feather tufts) is the “winged tiger of the woodlands.”Again, Forbush: “The Great Horned Owl is no respecter of persons. It kills weaker owls from the Barred Owl down, most of the hawks and such nocturnal animals as weasels and minks. It is the most deadly enemy of the Eastern Crow, taking old and young from their nests at night and killing many at their winter roosts. Game birds of all kinds, poultry, a few small birds, rabbits, hares, squirrels, gophers, mice, rats, woodchucks, opossums, fish, crawfish and insects are all eaten by this rapacious bird. It is particularly destructive of rats.”

Fishers often get blamed for the disappearance of domestic cats, but it could just as well be the work of a Great Horned Owl. They rule the night, with no natural enemies. Outside of your  home, both of these predators are in their home. Your cat is no match for either. The best way to protect your cat is to keep it indoors.

One early winter morning, I heard through my open window distant hoots: “Who’s awake? Me, too. Who’s awake. Me, too.” The Great Horned Owl was probably calling for its mate, but he also told me that the night belonged to him. I was glad to let him have it. I rolled over and went back to sleep.

Good birding!

Saturday, January 19, 2008

Barred Owl - Our Most Common Owl


Coming out of Brattleboro on a faux Spring day last week, just pass the Retreat Meadows I saw something white and brown in a tree close to the road - not the erect posture of a hawk, but a stubby, round posture that said, “Owl.” Fortunately, there were no vehicles in front of me or behind me so I could brake suddenly with safety. And the berm was wide, so I could exit rapidly and also safely. (Getting smacked by a vehicle when chasing a bird can ruin the chase.)

The Barred Owl was so close to the road that I only grabbed my camera. It was looking at something in the direction of the West River. I took a couple of pictures of the back of its head, then began maneuvering through the snow bank for a better angle. I got the better angle. The owl’s head swivelled at my noisy disturbance through the crunchy snow, considered me with distaste for a moment, and then flew.

Fortunately, it merely crossed the road and found a new perch among tall trees. It perched with complete ease, even as I again maneuvered along the roadside for an unobstructed view through the barren branches. My camera whirred away.

Then I began to hear a bird call that I don’t remember having heard before. Just before I had braked for the owl, I had made a quick stop to insure that the mockingbird perched on a wire was in fact a mockingbird and not a shrike. Now the mockingbird had come across the road. The unfamiliar calls I heard were strident, warning calls; the mockingbird began harassing the owl, boldly. It flew within a few feet of the owl, screaming as loudly as a mockingbird can scream, then flew back and yelled some more. A couple of times it appeared to peck at the back of the owl, and once it looked like it had landed on the owl - ever so briefly. To say that the mockingbird was unhappy with the owl’s presence in its neighborhood is an understatement.

Soon after the mockingbird began its noisy harassment of the owl, chickadees began calling. Downy Woodpeckers chimed in. The troops were rallying. The alarm had been sounded; the danger passed along. However, I did not see any of the small birds join the harassment, and, after a few minutes, the mockingbird allowed discretion to replace valor and moved some distance away. If there had been Blue Jays in the neighborhood, they would have been much more aggressive.

This harassment of a predator is called “mobbing.” It is a collective response to danger. At the very least it alerts the bird community to the threat and sometimes results in driving away the enemy. I have often seen crows harassing a Red-tailed Hawk along an interstate; they usually succeed in chasing away the hawk.

A few summers ago on a Newfane hill, I heard an unholy racket from a mob of crows. I could only get glimpses of the crows through the tree tops and I never saw the object of their odium. But in the deep woods, I was quite sure that they had found a Barred Owl and were more than a little unhappy about their discovery.

The Barred Owl is the most common owl in our area. At twenty-one inches, it is large. It is stocky, round-headed, with a grayish-brown back speckled white and a streaked (barred) belly. It has an orange-yellow beak and black eyes. It is the only owl likely to be seen in our area with black eyes.

The Barred Owl is a forest owl. It prefers mature deciduous and mixed forest with a closed canopy. The Great-horned Owl (a less common year-round resident) and the Great Gray Owl (a rare winter visitor to the northern US border) usually sit on the forest edge. Both have yellow eyes. The Barred Owl rarely sits on the forest edge.

The Barred Owl usually perches high in trees and close to the trunk. It hunts from a perch closer to the ground, and almost always at night. Unlike the powerful Great-horned Owl, the Barred Owl has weak talons which impose limits on what it is capable of killing. Most of its prey consists of small rodents: mice, rats, chipmunks, squirrels, moles, shrews, bats, young rabbits. In his life history, Bent cites the conclusion of a researcher: “Altogether, the Barred Owl seems endowed with about as mild a personality as a raptor could have yet maintain a predaceous existence, in some instances subsisting for considerable periods upon large invertebrates (insects and crayfish) or upon fish and amphibians.”

That being said, the Barred Owl is similar to most other predators. It will eat whatever is available, including birds. The list of documented birds in the food of the Barred Owl is long. While primarily nocturnal, there is plenty of evidence that it also hunts in broad daylight. The owl I watched being harassed by the mockingbird may not have been hunting, but like all raptors, it posed a potential danger to songbirds, and danger cannot be ignored.

The Barred Owl is normally a bird of the forest, but in the winter it may venture into villages and towns. The one I saw was very close to Brattleboro. Burlington has had several reports of an urban Barred Owl. And in general, there are been an unusual number of daytime sightings of this owl in recent weeks.

Last summer rodents had a prolific breeding year. This in turn produced higher than usual nesting success for many raptors that feed on the rodents, including Barred Owls. The young owls are inexperienced hunters; they often have a difficult time getting enough to eat. They feed on roadkill, but become victims themselves of vehicles. They often turn up on the doorstep of rehabilitators injured or emaciated.

Now add an early winter with deep snow, and the challenge of survival becomes greater, even for experienced adults. They must take food when and where they can find it. They must do so in these harsh conditions successfully for at least two more months. Then, sometime in late March, they may begin their nesting season.

This is a harsh winter for the owl, but a good winter for seeing owls. It is more common for us to hear the Barred Owl with its haunting “who cooks for you, who cooks for you, who cooks for you allll ....” - often as a back and forth conversation seeming to echo through the night forest.

In 1927, Edward Forbush witnessed a Barred Owl performance which I have to share with you. He wrote: “At one of my lonely wilderness camps in the month of March a pair of Barred Owls came to the trees over my campfire and made night hideous with their grotesque love-making, banishing sleep during the evening hours. Their courtship antics, as imperfectly seen by moonlight and fire light, were ludicrous in the extreme. Perched in rather low branches over the fire they nodded and bowed with half-spread wings, and wobbled and twisted their heads from side to side, meantime uttering the most weird and uncouth sounds imaginable. Many of them were given with the full power of their lungs, without any regard to the sleepers, while others were soft and cooing and more expressive of the tender emotions; sounds resembling maniacal laughter and others like mere chuckles were interspersed here and there between low wha whas and hoo-hoo-aws.”

Good birding.

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