Owl Eyes - ABC TV Science

click to watch video

An owl's eyes account for up to five percent of their body weight. Having large eyes enables an owl to see in low light conditions, but they've also given rise to the owl's incredible talent for rubber necking.

Owl's eyes can weigh up to five per cent of their bodyweight. That's like us having eyes as big as baseballs. Like us, owls have binocular vision so they can see in three dimensions, which is perfect for watching movies. Their necks have twice as many vertebrae as ours, so they can turn their heads two-hundred-and-seventy degrees, providing three-hundred-and-sixty degree vision.

They have three eyelids, one for blinking, one for sleeping, and a diagonal one that cleans like a windscreen wiper. Owls have extra-large corneas and pupils, and heaps of rod cells, giving them exceptional night vision. But they have fewer cone cells, so they see very little colour.

Owls can't roll their tubular eyes like we roll our spherical ones, which is why they never look exasperated. Their huge eyes give owls a look of wisdom. Ironic really, considering a group of owls is called a 'parliament'

Development of male Northern Bottlenose Whale (Hyperoodon ampullatus) melon

Development of male Northern Bottlenose Whale (Hyperoodon ampullatus) melon, with 1 being the oldest, 4 being the youngest and 5 being a female.

The next illustration has the same subject matter, although 120 years later. It’s fairly similar, although the oldest male head appears even more massive; amazingly, the Southern Bottlenose Whale (Hyperoodon planifrons) apparently has an even larger melon, although is unfortunately rarely photographed.

Gray, D. (1882) Notes on the characters and habits of the bottlenose whale (Hyperoodon rostratus). Proceedings of the Zoological Society of London 1882 726–731.

Hardy, M. (2005) Extent, Development and Function of Sexual Dimorphisms in the Skulls of the Bottlenose Whales (Hyperoodon spp.) and Cuvier’s Beaked Whale (Ziphius cavirostris). Master’s Thesis for University of Wales, Bangor

Owls

Facts About Owls

By About.com 

Saw-whet owl - Aegolius acadicusView owl pictures

Photo © Iculizard / Shutterstock.

Owls are a group of birds known for their distinct calls, nocturnal habits and silent flight. Owls are familiar to many people because they are often depicted in various ways in popular culture. They rank on par with bats and spiders as the most celebrated of Halloween creatures. Owls also appear as wise and noble characters in many children's stories, including Winnie the Pooh, Mrs. Frisby and the Rats of NIMH and Harry Potter

Here we'll go beyond the myths and the stories of owls to explore ten facts about real-world owls:

FACT: There are about 205 species of owls.

Owls belong to a group of birds that includes about 205 species. These species are sorted into two basic groups, the barn owls and the true owls.

Barn owls have a heart-shaped face, long legs and powerful talons. Barn owls are medium-sized birds with a wingspan of about 3½ feet. There are 16 species of barn owls, including the greater sooty owl, Australasian grass owl, ashy-faced owl, barn owl and Sulawesi owl.

True owls are more diverse than barn owls, with nearly 190 species in about 23 genera. Some better known true owls include screech owls, horned owls and saw-whet owls. True owls vary in size from the tiny elf owl to the bulky Eurasian eagle owl. True owls have a round facial disc, a short tail and a large head. Their color is muted (consisting of mostly brown, rust, gray, white and black) and their pattern is mottled, helping to conceal them from both predators and prey.

FACT: Owls are predators.

Owls feed on a wide variety of prey. Their main food source consists of small mammals such as mice, squirrels, voles and rabbits. They also supplement their diet by feeding on birds, insects and reptiles. Owls cannot chew their prey since, like all birds, they do not have teeth. Instead, they swallow small prey whole. They must tear larger prey into small pieces before swallowing. They later regurgitate pellets of indigestible material such as bone, fur and feathers.

FACT: Most owls are nocturnal.

Most owls hunt at night and in doing so avoid competition with daytime avian hunters such as hawks and eagles. Although nocturnal feeding is the norm for most owls, some species such as burrowing owls and short-eared owls feed during the day. Still other species, such as pygmy owls, feed at dusk or dawn.

FACT: Owls' eyes are fixed in their sockets.

Owls are unable to move their eyes within their sockets to a great extent, which means they must turn their entire head to see in a different direction. Because owls have forward-facing eyes, they have well-developed binocular vision.

FACT: Many species of owls have special flight feathers adapted for silent flight.

Owls have developed special feather adaptations that enable them to minimize the sound made when flapping their wings. For instance, the leading edges of their primary feathers have a stiff fringes that reduces noise while the trailing edge of their primaries have soft fringes that helps to reduce turbulence. Downy feathers cover the surfaces of the wing to further reduce sound.

FACT: Owls have long been a part of human folklore and legend.

Owls are depicted in cave paintings in France that date back 15,000 to 20,000 years. Owls also appear in Egyptian hieroglyphics. They have held a variety of symbolic roles in culture and have represented misfortune, death, prosperity, and wisdom.

FACT: The tufts of feathers atop some owl's heads, referred to as 'ear tufts' are for display only.

Owls' ears are located on the facial disc behind the eyes and are concealed by feathers. Owls have an acute sense of hearing that helps them locate and capture prey. In some species, the ears are located asymmetrically on either side of the facial disc to enhance their ability to pinpoint the origin of the sounds they hear by sensing the minute difference in the time that sound reaches each ear.

FACT: Owls have strong feet like raptors, with two forward-facing toes and two backward-facing toes.

The structure of an owl's foot is referred to as zygodactyl, which means that tow of the toes face forward while two face backward. This arrangement enables the owls to capture and grasp prey with greater ease. Sometimes, the third toe can be rotated forward into a position occasionally used for perching.

FACT: Owls have a long, hooked bill.

In many species, the bill is partly concealed by feathers so it appears smaller than it actually is. Owls use their sharp bill to tear their food.

FACT: Owls do more than just hoot—they create many different vocalizations.

Owls create a wide variety of sounds or vocalisations. The familiar hoot is usually a territorial declaration, though not all species are able to hoot. Other sounds owls might make include screeches, hisses, and screams. Owl vocalizations are loud and low-pitched. Their cries travel well through the night air, enabling them to locate mates and declare territories despite the darkness.

March Bird Facts

Modern-day birds do not have any teeth (ancient birds did have teeth). Birds have a tongue, but unlike our tongue, a bird's tongue has a bone in it.

Birds spend most of their time looking for food. Most birds are insectivores (they eat insects). Some birds, like owls and eagles, are carnivores (meat-eaters). Some birds, like the hummingbird, grouse, and Canada goose, are mostly herbivores (plant-eaters). Other birds, like starlings, are omnivores (plant- and meat-eaters). Some birds (like the toucan) are fructivore (fruit-eaters)

Birds mostly use their keen eyesight to find food. They use their beak and their claws to get bugs, worms, small mammals , fish, fruit , grain, or nectar.

Birds play a very important part in the natural control of insects and in the dispersal of seeds. Some birds, like the tiny, nectar-eating hummingbird are important pollinators of some flowering plants.

Nests and Eggs:

The ostrich lays the largest birds' eggs; their eggs are up to 4.5 x 7 inches (11 x 18 cm) across and weigh 3 pounds (1400 g).

Birds bear their young in hard-shelled eggs which hatch after some time. Some birds, like chickens, lay eggs each day, others (like the maleo) may go for years between laying eggs.

Birds build nests for breeding in trees, on cliffs, or on the ground. Most birds are taken care of by at least one parent until they are able to fly and get their own food.

Bird	Incubation Period
Chicken	20-22 days
Ostrich	42-50 days
Parakeet (budgie)	27-28 days
Pigeon	14-18 days
Swan	30 days
Toucan	18 days

The incubation period of bird eggs varies from species to species. There's also some variability due to the temperature.

There are numerous species of bird found in a wide variety of habitats all around the world. 

Birds are one of the most thriving groups of animals on the planet as they generally have their habitat (the skies) to themselves.

Birds can be easily distinguished from other animals due to their sharp, pointed beaks, thin legs, wings and feathers covering their bodies. 

Although all bird species have wings, some are actually flightless animals that only use their wings for balance and not for flying. Where other birds, such as penguins, use their wings for swimming. 

Birds are often omnivorous animals, generally eating nearly anything that they can find. Most species of bird survive on a diet primarily consisting on insects and plants such as fruits, nuts, berries and seeds. 

Birds are also distinctive in the fact that they lay eggs in a similar way to other animal groups such as fish and reptiles. Birds often make nests in the trees or on the ground in which to lay their eggs.

Birds (class Aves) are bipedal, warm-blooded, oviparous vertebrate animals. 

Most scientists believe that birds evolved from theropod dinosaurs. 

Ranging in size from tiny hummingbirds to the huge Ostrich and Emu, there are between 9,000 and 10,000 known living bird species in the world, making Aves the most diverse class of terrestrial vertebrate. 

A bird is characterized by feathers, a toothless beak, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a light but strong skeleton. 

All birds have forelimbs modified as wings and most can fly. 

Birds are important sources of food, acquired either through farming or hunting. 

Numerous species of birds are also used commercially, and some species, particularly songbirds and parrots, are popular pets. 

Birds figure prominently in all aspects of human culture from religion to poetry and popular music. 

Numerous species of birds are threatened with extinction by human activities and as a result efforts are underway to protect them.

Common Backyard Bird Nest Identification

http://lansingwbu.blogspot.com.es/2011/03/common-backyard-bird-nest.html

The art applied to building a nest is very individual for each bird species.

Bluebird, Eastern – a neat, woven cup-shaped nest made mainly from fine grass or pine needles inside an old woodpecker nest or bird house.

Cardinal, Northern – Builds cup-shaped nest low in dense shrub from twigs, weeds, grass, and leaves.

Chickadee, Black-capped – Another cavity nester that starts building her nest with a moss base and tops it with animal fur or cottony plant fibers.

Cowbird, Brown-headed - Cowbirds do not build their own nest – Instead they lay one egg in several nests and let other birds foster their young.

Dove, Mourning – On the fork of a shrub or tree or sometimes on the ground or on an outside workbench or gutter. Doves are known for their inappropriate nesting sites. Nest is usually a fragile, shallow platform of twigs made by the male.

Goldfinch, American – Nests in August. At a fork of a deciduous tree the female builds a nest from grass and spider silk and lines it with plant down and hair.

House Finch – Messy cup-shaped nest made of twigs, grasses, plant fibers, leaves, rootlets, hairs, string and wool, lichens. Sometimes nest in wreaths on doors of houses or hanging plants.

House Sparrow – Tall messy nest made from a collection of loose litter, grasses, feathers and more stuffed into a bird house.

Hummingbird, Ruby-throated – Female alone constructs cup-shaped nests with a diameter about the same size as a quarter. They start to build with bud scales and spider webs and then camouflage the outside with lichen. To cushion the inside of the nest they use cotton or some other plant fluff like dandelions.

Jay, Blue – Male and female build bulky stick nest in a crotch of a tree or tall shrub.

Oriole, Baltimore – Nests high in deciduous trees. Female weaves a hanging pouch at the end of a branch from grasses, plant stems and grape vines and then lines it with fine grasses and animal fur.

Robin, American – Builds sturdy cup nest in coniferous or deciduous tree or shrub. Made from grass, moss and loose bark and cemented with mud.

Swallow, Tree – Inside a bird house they build a cup-shaped nest of grass or pine needles, usually lined with lots of fluffy feathers to cover the eggs.

Woodpeckers – Most of Michigan’s woodpeckers use their chisel-like bills to excavate their cavity nests in trees, and line it with woodchips. They will also use a bird house that is packed with wood chips.

Wren, House – Male fills a many bird houses full of twigs and lets the female choose. Females then take over building the nest with cottony spider cocoons, fine fibers and downy feathers.

Book Review: Zero the Hero

By Joan Holub 
for Cynthia Leitich Smith's Cynsations

Zip. Zilch. Nada. That's what all the other numbers consider Zero in my new picture book that’s about, well, nothing.

Zero doesn't add anything in addition. He's of no use in division. And don't even ask what he does in multiplication. (Hint: Poof!)

Still, he knows he's worth a lot, and when trouble comes, Zero swoops down just in time to prove that his talents are innumerable.

This book grew from a conversation with a teacher, who mentioned that she uses the Zero the Hero concept to teach place-holding to her students. In her classroom, Zero is a hero because he enables us to count beyond the number nine. Without him, we’d be like the ancient Romans, unable to do much in the way of math.

I immediately visualized Zero as an underdog math superhero, complete with cape. But it took me about five years to actually finish writing a book about him. Lucky thing, because the manuscript hit my editor’s desk just as she was working with a wonderful New York Times-bestselling artist named Tom Lichtenheld, who agreed to illustrate it.

In this kind of “faction” (a blend of fiction and fact), the fiction component is always paramount. It’s the story. Young readers won’t necessarily pick up this picture book to learn math facts. They’ll likely want the story to entertain them, make them root for the characters, and wonder how it will all turn out.

Sure, Zero the Hero subtly teaches place-holding and arithmetic operations like addition and subtraction. It touches on stuff like rounding up and down, and even/odd numbers (and the fact that the number eight resembles a snowman). But all of that is secondary. I just hope kids find it to be a fast-paced, funny story. And who doesn’t love a superhero?

I submitted this picture book to Henry Holt/Macmillan as a dummy, complete with very rough black-line sketches, even though I didn’t intend to illustrate it. When writing easy readers, chapter books, and tween or middle grade, I submit a traditional, typed manuscript instead.

But when it comes to picture books, I think visually. So I create dummies. Sometimes they’re just words taped on pages that I can turn so as to get a feeling of how the story unfolds. Those never go to an editor. Other times—as in the case of Zero the Hero—I draw sketches, generally spiff things up, and actually submit the dummy itself.

Why? If you were an editor, and a book like Zero the Hero came your way asking to be published, which of these examples would you find easier to envision at first glance--my dummy page or my typewritten text?

(typed manuscript)
Number 6, speaking to Zero: Hey! Aren’t you a Froot Loop? I love those.
Zero: No, I’m Zero the Hero!
Number 6: Um, yeah I don’t think so. Are you a donut?
Zero: No!
Number 6: I’ve got it! You’re the letter “O”.
Zero: No! How many times to I have to tell you?
Number 6: Six.
Zero: Grrr.

Not every picture book requires that an author make a dummy. However, if you have a cast of ten numbers or more, all with something to say, and sometimes saying it in speech balloons—a dummy could be a good vehicle for communicating your vision to an editor. And you don’t have to be a professional artist to make one that gets your ideas across.

Speaking of creative ways to get your ideas across, look how Tom Lichtenheld used this birdhouse to display his earliest character sketches. Although Zero’s ‘look’ evolved quite a bit from this initial point, I was really wowed when I got this in the mail from Tom. It was my introduction to his humor and generous spirit, and I knew right away that the process of creating this book was going to be something special with him involved.

After the book was finished, our collaboration continued. Tom and I also wrote the script for an animated book trailer short about Zero the Hero that’s lots of number fun. We hope everyone will take a look. After all, you’ve got nothing to lose!

Cynsational Notes

Visit Joan Holub at her blog, website, or on Facebook.

Zero the Hero zoomed into bookstores Feb. 28. It’s published by Henry Holt/Macmillan for ages 6 to 10 and up. Zero the Hero excerpts and sketches copyright © 2012 by Joan Holub. Zero the Hero art copyright © 2012 by Tom Lichtenheld.

25 cute hairstyle ideas for little girls

Source