Eagle Owls - reclaimed from elsewhere.
Jul. 31st, 2004 09:43 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
kuangning(I'm pulling it as a writing sample suitable for inclusion with my resume. Opinions?)
It is just past twilight, and golden eyes scan the area. A small animal scurries below. Quick as thought and just as silently, a shadow unfurls, stoops, glides. There is just enough time for the hapless animal -- perhaps a mouse, perhaps a young, unwary rabbit -- to make one frightened sound. The eagle owl is a formidable hunter, and almost never misses.
Habitat:
Eagle owls are found throughout the world, with the exceptions of Australia and the southwest Pacific Islands. They inhabit the Sahara desert, African jungles, and almost every less extreme habitat, from Sweden to Asia. They are not widely found in the UK, however, as they were once numerous there but were then hunted almost to extinction. They are thought to have existed on this planet for millions of years -- 75 million or so, in fact. They have no natural enemies, and are highly adaptable. They are also long-lived: a bird which survives its first year in the wild can expect to live about 15 to 20 years, and birds raised in captivity have lived as long as 60 years. Given those facts, then, perhaps the single most amazing thing about eagle owls is how many people have never seen one. Their elusiveness seems to be the product of two special traits they share with most other owls: protective coloration, and near-silent flight.
Characteristics:
Owls in general, and eagle owls in specific, while largely preferring to be nocturnal, are also capable of functioning during the daytime. Their eyes are supremely adapted for making use of any available light (no animal can truly see in complete darkness, including owls), but they also include the nictitating membrane that all birds of prey have. They can stare directly into the sun without harm. Because of the adaptation which gives them their remarkable eyesight, however, owls are unable to move their eyes. To compensate for this, they are able to turn their heads far beyond most birds' range of motion. Most birds sleep with their heads pillowed on their backs, beaks tucked under their wings. Owls can achieve that position and then turn past it another 45 degrees.
All eagle owls, including the great horned owl, the only North American eagle owl, have a basic buff to orange coloration, streaked with brown. The mottling, on the other hand, varies according to the bird's accustomed habitat. All eagle owls are tufted, meaning they have ear tufts. These feather formations atop the birds' heads are sometimes mistaken for ears. In actuality, the tufts are merely for display, and their position is indicative of the bird's mood. They also aid in camouflage.
Their other great advantage, namely their fast and silent flight, is a product of special wing and feather configuration. Their wings are generally large compared to body size, and rounded, with a great deal of surface area. This allows for soaring flight and slow gliding, cutting down on the need for flapping and excess energy expenditure. Many types of eagle owl, in fact, prefer to glide while hunting, scanning the area below while on the wing and then stooping quickly for prey.
Feather Types:
All birds have up to five feather types, and eagle owls are no exceptions. The first feathers, filoplumes, actually have very little to do with flight itself. They are hairlike feathers which cover the body. Filoplumes are themselves covered by other feathers, and act as sensors, telling the bird how the other feathers are aligned (or misaligned, as the case may be), which aids in preening. They are short, with just one or two barbs on the end.
The next important feather type is down. Eagle owls are covered in down while they are chicks and unable to regulate their body temperatures well. With their fledging, they lose most of the down as their adult feathers grow in. Down's primary function is to warm the bird, and eagle owls have adapted by growing a special contour feather which has downy barbules close to the skin. This effectively combines the down function into the contour feather's usual function. As the name suggests, it is contour feathers which give the bird its characteristic contours of the wings, tail, and body. Between the contour feathers and other two feather types are semiplumes. These function to fill in and support the primary flight feathers, and perhaps also to provide another layer of protection and insulation.
The primary flight feathers are contour feathers. In eagle owls, and most other owls, they are further adapted to include special barbs at the leading edges. This is the primary reason why owls can fly silently. The barbs break the flow of wind over the wing, effectively muffling the characteristic whooshing sound that they would otherwise make. Owls which prefer to hunt in the daytime often lack this special adaptation.
Nesting and Mating Habits:
Eagle owls generally breed in late January or early February, unlike most birds and creatures which tend to produce young in the spring. This early breeding has one great advantage: spring to summer is when the young are ready to be taught to hunt, and game is generally plentiful then, in the form of other creatures' inexperienced offspring. The size of the clutches vary from one to four, and is very dependent upon food supply, so the early breeding allows for larger clutches than might otherwise be feasible. The male is very attentive to the female, and does all the hunting for them both in most cases. The female generally will refuse to leave the clutch until the chicks have grown to a good size. Sometimes this extends even to the point of allowing herself to be picked up, although since nesting females can be very protective, that experiment is not recommended. Eagle owls do not build their own nests. Instead, they adopt other birds' nests, adding nothing to them. Equally as often, they clutch on the ground. This may not be as disadvantageous as it sounds at first. The young often grow to such a size before they can fly properly that they simply fall from the nests, and spend the rest of their time clambering about on the ground until they can fly. Faced with the demand of feeding the flightless and clumsy young birds, both parents will often hunt in the daytime as well during this time.
As with most other creatures in the wild, the first winter proves the most dangerous time for the eagle owl fledglings, even with those advantages. The mortality rate for the first winter is generally high. However, those who survive to the spring will be formidable predators, and can look forward to a long lifespan with very little to threaten them.
________________________
Sources:
"Eagle Owl." World Book Encyclopedia.
Chicago, Il: World Book, Inc., 1994.
R.D Lawrence. Owls: The Silent Flyers.
Buffalo, NY: Firefly Books, 1997.
Eagle Owl | Animal Facts | Chaffee Zoological Gardens of Fresno.
Chaffee Zoological Gardens of Fresno.
http://www.chaffeezoo.org/animals/eagleOwl.html.
15 Jan. 2004
"Eagle Owl." Encyclopædia Britannica. 2004.
Encyclopædia Britannica Premium Service.
http://www.britannica.com/eb/article?eu=32239.
15 Jan. 2004
Original article.
It is just past twilight, and golden eyes scan the area. A small animal scurries below. Quick as thought and just as silently, a shadow unfurls, stoops, glides. There is just enough time for the hapless animal -- perhaps a mouse, perhaps a young, unwary rabbit -- to make one frightened sound. The eagle owl is a formidable hunter, and almost never misses.
Habitat:
Eagle owls are found throughout the world, with the exceptions of Australia and the southwest Pacific Islands. They inhabit the Sahara desert, African jungles, and almost every less extreme habitat, from Sweden to Asia. They are not widely found in the UK, however, as they were once numerous there but were then hunted almost to extinction. They are thought to have existed on this planet for millions of years -- 75 million or so, in fact. They have no natural enemies, and are highly adaptable. They are also long-lived: a bird which survives its first year in the wild can expect to live about 15 to 20 years, and birds raised in captivity have lived as long as 60 years. Given those facts, then, perhaps the single most amazing thing about eagle owls is how many people have never seen one. Their elusiveness seems to be the product of two special traits they share with most other owls: protective coloration, and near-silent flight.
Characteristics:
Owls in general, and eagle owls in specific, while largely preferring to be nocturnal, are also capable of functioning during the daytime. Their eyes are supremely adapted for making use of any available light (no animal can truly see in complete darkness, including owls), but they also include the nictitating membrane that all birds of prey have. They can stare directly into the sun without harm. Because of the adaptation which gives them their remarkable eyesight, however, owls are unable to move their eyes. To compensate for this, they are able to turn their heads far beyond most birds' range of motion. Most birds sleep with their heads pillowed on their backs, beaks tucked under their wings. Owls can achieve that position and then turn past it another 45 degrees.
All eagle owls, including the great horned owl, the only North American eagle owl, have a basic buff to orange coloration, streaked with brown. The mottling, on the other hand, varies according to the bird's accustomed habitat. All eagle owls are tufted, meaning they have ear tufts. These feather formations atop the birds' heads are sometimes mistaken for ears. In actuality, the tufts are merely for display, and their position is indicative of the bird's mood. They also aid in camouflage.
Their other great advantage, namely their fast and silent flight, is a product of special wing and feather configuration. Their wings are generally large compared to body size, and rounded, with a great deal of surface area. This allows for soaring flight and slow gliding, cutting down on the need for flapping and excess energy expenditure. Many types of eagle owl, in fact, prefer to glide while hunting, scanning the area below while on the wing and then stooping quickly for prey.
Feather Types:
All birds have up to five feather types, and eagle owls are no exceptions. The first feathers, filoplumes, actually have very little to do with flight itself. They are hairlike feathers which cover the body. Filoplumes are themselves covered by other feathers, and act as sensors, telling the bird how the other feathers are aligned (or misaligned, as the case may be), which aids in preening. They are short, with just one or two barbs on the end.
The next important feather type is down. Eagle owls are covered in down while they are chicks and unable to regulate their body temperatures well. With their fledging, they lose most of the down as their adult feathers grow in. Down's primary function is to warm the bird, and eagle owls have adapted by growing a special contour feather which has downy barbules close to the skin. This effectively combines the down function into the contour feather's usual function. As the name suggests, it is contour feathers which give the bird its characteristic contours of the wings, tail, and body. Between the contour feathers and other two feather types are semiplumes. These function to fill in and support the primary flight feathers, and perhaps also to provide another layer of protection and insulation.
The primary flight feathers are contour feathers. In eagle owls, and most other owls, they are further adapted to include special barbs at the leading edges. This is the primary reason why owls can fly silently. The barbs break the flow of wind over the wing, effectively muffling the characteristic whooshing sound that they would otherwise make. Owls which prefer to hunt in the daytime often lack this special adaptation.
Nesting and Mating Habits:
Eagle owls generally breed in late January or early February, unlike most birds and creatures which tend to produce young in the spring. This early breeding has one great advantage: spring to summer is when the young are ready to be taught to hunt, and game is generally plentiful then, in the form of other creatures' inexperienced offspring. The size of the clutches vary from one to four, and is very dependent upon food supply, so the early breeding allows for larger clutches than might otherwise be feasible. The male is very attentive to the female, and does all the hunting for them both in most cases. The female generally will refuse to leave the clutch until the chicks have grown to a good size. Sometimes this extends even to the point of allowing herself to be picked up, although since nesting females can be very protective, that experiment is not recommended. Eagle owls do not build their own nests. Instead, they adopt other birds' nests, adding nothing to them. Equally as often, they clutch on the ground. This may not be as disadvantageous as it sounds at first. The young often grow to such a size before they can fly properly that they simply fall from the nests, and spend the rest of their time clambering about on the ground until they can fly. Faced with the demand of feeding the flightless and clumsy young birds, both parents will often hunt in the daytime as well during this time.
As with most other creatures in the wild, the first winter proves the most dangerous time for the eagle owl fledglings, even with those advantages. The mortality rate for the first winter is generally high. However, those who survive to the spring will be formidable predators, and can look forward to a long lifespan with very little to threaten them.
________________________
Sources:
"Eagle Owl." World Book Encyclopedia.
Chicago, Il: World Book, Inc., 1994.
R.D Lawrence. Owls: The Silent Flyers.
Buffalo, NY: Firefly Books, 1997.
Eagle Owl | Animal Facts | Chaffee Zoological Gardens of Fresno.
Chaffee Zoological Gardens of Fresno.
http://www.chaffeezoo.org/animals/eagleOwl.html.
15 Jan. 2004
"Eagle Owl." Encyclopædia Britannica. 2004.
Encyclopædia Britannica Premium Service.
http://www.britannica.com/eb/article?eu=32239.
15 Jan. 2004
Original article.
![[identity profile]](https://www.dreamwidth.org/img/silk/identity/openid.png){kind=small}
no subject
Date: 2004-07-31 06:54 pm (UTC)lj-cut, or at least take the surplus line feeds out?
no subject
Date: 2004-07-31 06:56 pm (UTC)no subject
Date: 2004-07-31 08:12 pm (UTC)no subject
Date: 2004-07-31 09:02 pm (UTC)no subject
Date: 2004-07-31 09:04 pm (UTC)no subject
Date: 2004-07-31 09:06 pm (UTC)no subject
Date: 2004-08-01 01:12 am (UTC)It didn't bore me, although I skimmed the part about the feathers a bit. Aside from that I will probably retain everything (and I *do* remember why they can fly silently).
no subject
Date: 2004-07-31 09:01 pm (UTC)This confused me:
To compensate for this, they are able to turn their heads, not just the 360 degrees that most birds can achieve, but up to 45 degrees beyond that on either side. Most birds sleep with their heads pillowed on their backs, beaks tucked under their wings. Owls can achieve that position and then turn past it another 45 degrees.
The first part suggests that an owl could turn its head a total of 405 (360 + 45) degrees.. the part about sleeping though says they can turn it around 180 to tuck their head under their wing, but could also possibly go another 45 degrees, as if that were the limit instead of 405. The fact that the number 45 is used twice makes me think it's the same limit, but the numbers aren't the same..
I'm not nearly as fluent at this language as you are :P so I'm sure that didn't make sense.. just my confusion about the numbers.
no subject
Date: 2004-07-31 09:03 pm (UTC)no subject
Date: 2004-07-31 09:07 pm (UTC)"To compensate for this, they are able to turn their heads." Dunno why that sounds a little awkard to me.. could I suggest a comparitive or something, like "they are able to turn their heads.. in a greater range of motion that other animals" :P or something similar
no subject
Date: 2004-07-31 09:09 pm (UTC)no subject
Date: 2004-07-31 09:05 pm (UTC)no subject
Date: 2004-07-31 09:08 pm (UTC)