Wednesday, October 31, 2012

Exciting New Bird Food at Wild Birds Unlimited Stores

Right now we are seeing an increase in activity at the feeders. Some birds from Canada and the U.P. are making mid-Michigan their winter resting place. Some Dark-eyed Juncos, Red-Breasted Nuthatches, Pine Siskins, Redpolls, Crossbills, and Snow Buntings are just a few birds seen here only during the winter. The White-throated and White-crowned Sparrows are common migrants in mid-Michigan from mid-September to mid-November.

A few other feeder birds that you will see all year as well as during the winter are the Mourning Dove, Downy Woodpecker, Red-bellied Woodpecker, Blue Jay, American Crow, Black-capped Chickadee, Tufted Titmouse, White-breasted Nuthatch, European Starling, Northern Cardinal, American Goldfinch, and of course the House Sparrow to name a few.

And the Wild Birds Unlimited store in East Lansing, Michigan have lots of food and feeders to attract all these birds up close. One of our most popular feeders is the seed cylinder feeder.

The Seed Cylinder feeders are popular with people who have been bird feeding a long time and for beginners. It is one of the easiest feeders to maintain and attracts a wide variety of birds.

For people that aren't able to get out to fill feeders often during our harsh Michigan winters this feeder is ideal. Depending on bird activity in your yard, a 2lb cylinder can last weeks and a 4.5lb cylinder can last months.

Oh the weather outside is frightful, But this feeder is so delightful!
Now we’ve developed a new adorable seed cylinder shape for winter. Our regular Bird Food Cylinders offer a convenient alternative way to feed the birds. And Buttons the Snowman, a whimsical seed cylinder is a fantastic way to introduce friends and family to the hobby of bird feeding.

Available for a limited time only, our Snowman Seed Cylinder is a seasonal mix of safflower, sunflower chips, peanuts, cherries, blueberries and papaya to attract a variety of birds. Simply slide the Snowman Seed Cylinder onto our WBU Seed Cylinder Feeders or WBU Dinner Bell™ feeder and enjoy the feathered holiday visitors.
The Snowman Seed Cylinder is the perfect holiday addition to any yard and 
a great gift idea for the nature lovers on your list.

Dimensions: 7½" x 3" diameter
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Tuesday, October 30, 2012

Mother Nature in disguise

Mother Nature (sometimes known as Mother Earth) is a common personification of nature. Also known as Nokomis, Algonquian legend says that "beneath the clouds lives the Earth-Mother from whom is derived the Water of Life, who at her bosom feeds plants, animals and human."

The word nature comes from the Latin word, natura, meaning birth. The personification of Mother Nature, was widely popular in the Middle Ages and can be traced to Ancient Greece where the earliest written literal references to the term "Mother Earth" occur in 13th/12th century BC.

Nature, the Gentlest Mother


"It's not your imagination" ~ 2007 movie poster for Premonition
By Emily Dickinson
Nature the gentlest mother is,
Impatient of no child,
The feeblest of the waywardest.
Her admonition mild

In forest and the hill
By traveller be heard,
Restraining rampant squirrel
Or too impetuous bird.

How fair her conversation
A summer afternoon,
Her household her assembly;
And when the sun go down,

Her voice among the aisles
Incite the timid prayer
Of the minutest cricket,
The most unworthy flower.

When all the children sleep,
She turns as long away
As will suffice to light her lamps,
Then bending from the sky

With infinite affection
And infiniter care,
Her golden finger on her lip,
Wills silence everywhere.

Source: Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Mother_Nature

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Monday, October 29, 2012

What Bird Seeds Goldfinches Like Best

I'm writing to scold you and I want you to reprint this on your computer newspaper. I did not think it made a difference where I bought my finch food. You said it made a "HUGE" difference. I took home a small bag of your thistle and I noticed it did make a HUGE difference!

Now I have so many finches at the feeder I will have to come in every week to keep the feeders full of your seed. Why do the other stores bother selling bird food when it is so inferior? ~ Lansing, MI

Attracting more goldfinches is very rewarding. They are bright, cheery songbirds that the great state of Michigan is lucky enough to have year round! However, it's very common to here people tell me they just don't have large numbers goldfinches.

Seed
There are a lot of bird seed blends containing many different types of seed. So how do you know which bird seed to buy? Wild Birds Unlimited uses research from a three-year, one million dollar study of bird seed and feeder preferences in the United States and Canada.

We know that goldfinches eat a variety of seeds. Sunflower and Nyjer thistle are two of their favorites at the feeders but it has to be fresh. One way to check your seed is to pinch it with your fingernails and see if any oil comes out. The finches use their bills to twist the seed and sip the oil and then drop the shell. If your seed has dried out, your feeder will be skipped. (Wild Birds Unlimited receives a fresh load of seed each week).

Feeders
Feeders also attract the American Goldfinches. We sell a variety of finch feeders. My favorites are the Mesh Finch Feeders. They not only let the finches land and feed in whatever position they choose, but they also allow air circulation to keep your Nyjer Thistle as dry and fresh as possible; something that's very important to these picky eaters. (Nyjer thistle is the common name used to identify a tiny black birdseed but is not related to the purple, prickly, Canada Thistle weed.)

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Sunday, October 28, 2012

What birds do when a hurricane hits

Can birds predict that tornado-like winds are about to hit?

Most birds have a special middle-ear receptor called the Vitali organ, which can sense incredibly small changes in barometric pressure. So if the activity at feeders suddenly becomes much more intense a storm may be approaching. Birds flying low or lining up on power lines also indicate swiftly falling air pressure.

The small birds like chickadees fly as little as possible and try to wait out storms in patches of dense vegetation or roosting boxes that give protection. And they appreciate feeders.

During storms birds may think of your feeder as a known source of food. While not dependent on feeders, birds don't feel like foraging for food in bad weather. Feeders make it easier for wild birds to brave a storm.

High winds make flying difficult. I love when the wind blows but know it is hard on the birds, so I keep the feeders full. If they can navigate it to the feeder, they deserve a good meal.
 
You'll see some birds that seem to be flying in place, while other birds like the Blue Jays seem to be able to navigate and take advantage of the wind. They zoom in at the feeder like a bullet. 
 
After a storm, brush piles of leaves and other natural debris can be piled up to provide birds with a place to take cover from the weather and hide from predators.

There should also be available drinking water to allow birds to maintain a healthy metabolism and stay warm. If weather turns freezing, you can use a heated bird bath or add a heater to your existing plastic, metal or stone bird bath.
 
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Saturday, October 27, 2012

Small, gray, short-bodied, long-tailed, big-headed flycatcher

The Eastern Phoebe (Sayornis phoebe) is one of the first birds to return to the breeding grounds in spring and one of the last to leave in the fall. They arrive for breeding in mid-March, and return to winter territories in September and October.
STEM Eastern Phoebe animation

Eastern Phoebes breed all across Michigan in open deciduous woodlands, usually near water. They spend the winter primarily across the southeastern United States, ranging as far north as Virginia, southern Kentucky, and central Oklahoma and as far south as central Mexico. An insectivorous, this tyrant flycatcher sits alertly on low perches, often twitching their tail as they look for flying insects. They also eat fruits and berries in cooler weather.

The Eastern Phoebe's call is a sharp chip, and their characteristic song  fee-bee gave them their common name. They are a gray sparrow-sized bird with a lighter gray belly and no eye rings, no obvious wing bars and an all dark bill and legs. The Eastern Phoebe is a fairly short-bodied, long-tailed flycatcher with a thin pointed bill and a big-headed look when they puff up their small crest.

Sources:

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Friday, October 26, 2012

Feathers developed as a form of communication not flight

Were feathers used originally as a form of communication and not for flight? A new theory is that when feathers first formed on dinosaurs they were used more for flashing and waving to impress and attract potential mates.  

In Canada, fossilized bones of an ornithomimiddinosaur preserved evidence of fossil feathers that could not possibly be used for flight. Debates began on the purpose of feathers if not for flying, like protection from the elements, help to nestle eggs, threaten predators or attract mates.

Because the juvenile ornithomimus had a thin, downy coat and the adults had bigger, showy feathers, scientists believe that the wings were used for purposes later in life, like reproductive activities, such as courtship displays.

Richard Prum, an expert on birds present and past at Yale University, says recent discoveries do suggest that feathers were some kind of signal. "The idea is that these were for communication," says Prum, "and that's fascinating, because we recently have new evidence that the feathers of dinosaurs were pigmented, and perhaps pigmented very boldly, so that already implied that there was a communication function for early feathers."

In fact, Prum says the need for dinosaurs to "look hot" had some important consequences for today's birds. "The evolution of attractiveness or beautiful traits may have had an important role in the origin and early diversification of feathers," Prum says.

.
Sources: 
- Science - www.sciencemag.org/content/338/6106/510
- University of Calgary - http://www.ucalgary.ca/news/releases/october2012/first_feathered_dinosaurs

Related articles:
- Types of Bird feathers http://goo.gl/W9rzP
- Why Birds don't Freeze After They Take a Bath in the Winter: http://bit.ly/mPa0Y8
- How small birds stay warm in the winter: http://bit.ly/q3dDqj  
- Why birds molt: http://bit.ly/ox5Hwi
- Blue Jays aren't blue: http://bit.ly/pMN37k
- Fossils of colored feathers: http://bit.ly/nc2UeA

Thursday, October 25, 2012

Photo Share: Northern Cardinal and Black-capped Chickadee

"My favorite weather is bird-chirping weather."
~ quote from Loire Hartwould
Thank you for sharing your photos! Holly sent us lots of fabulous photos that I will continue to share in the coming weeks on our Friday photo share. If anyone else would like to share a photograph of nature send it to bloubird@gmail.com and I'll put it on the Friday Photo posts. 

Wednesday, October 24, 2012

The Wild Birds Unlimited Bird Feeding System is the Best!

The Advanced Pole System - Looks Great, Stays Straight! Wild Birds Unlimited's patented Advanced Pole System (APS) is comprised of interchangeable hardware pieces, that lets you add or subtract bird feeders, birdhouses and other bird feeding accessories, giving you the ability to create and customize your bird feeding station with over 3,000 combinations — it is all up to you!

How Does It Work?
It’s easy! Just insert a screwdriver into the hole at the middle of the 4-foot Base Pole and twist it into the ground using the convenient corkscrew auger connected at the bottom of the pole. Next slide the Stabilizer onto the Base Pole and push into the ground. Tests show the stabilizer holds the pole straight in up to 35 MPH wind gusts. Plus, it is lawnmower-friendly.

Get Creative! 
Create your own unique setup by selecting the bird feeder, birdhouse, bird bath, or bird feeder supplies you want. The APS parts fit together easily, and no special tools are required. Birds will flock to your new APS station in no time. So, sit back and enjoy the show.

It’s Flexible!
The APS was designed to accommodate all feeders with many hanging accessories from which to choose. Suet feeder, peanut feeder, tube feeder, wooden feeder, one feeder, many feeders — the Advanced Pole System is the ultimate solution to all your birdfeeding needs.

Don’t have a yard? Use the Advanced Pole System to create a birdfeeding station on your deck. It’s that flexible!
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Wild Birds Unlimited - Advanced Pole System (APS) is a revolutionary bird feeding pole that has interchangeable hardware pieces that lets you design the perfect feeding station for your needs. You can make it as tall or as short as you want with as many arms or attachment as needed.

We have a wall of “extras” that can customize your set-up with several different arms to add as well as perching branches, suet attachments, side dishes, baffles and a choice of several finials.

To help you construct your masterpiece come in to our WildBirds Unlimited - East Lansing, MI store or go to wbu.com/aps for more examples.  If this is all too confusing we have a basic setup all boxed up and ready to take home or give as a gift.
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Australian Ringneck Parrots

Australian Ringneck Parrots
by Mark Holmes, Angaston, S.A.

Classification

The ringneck family of Australian parrots belong to the genus, Barnardius.  They are also referred to as Broad-tailed parrots.  The ringneck group are widespread throughout the drier areas of Australia and there are four main subspecies recognised, namely :
Twenty-eight parrot
Port Lincoln parrot
Mallee ringneck
Cloncurry parrot
A hybrid subspecies between the Port Lincoln and Twenty-eight parrot, the so-called wheatbelt hybrid or the yellow-fronted Twenty-eight parrot, also exists. All are widely kept in avicultural collections and are a worthwhile addition to any fanciers collection.
The Twenty-eight and Port Lincoln parrots and the wheatbelt hybrid are all very similar in coloration and I am sure there has been many a friendly argument on an aviary visit amongst aviculturists as to which is which.

Male/Female

In the Twenty-eight parrot, the sexes are alike in body colouration. It is a large bird, being approximately 40cm in length, of which 20cm is tail. The male however, is slightly larger than the female and has a broader head. Its head is dull black; lower ear coverts violet blue; it has a narrow yellow collar around the nape; the back and wings are bright green; the outer webs of the primary feathers are dark blue; the throat and breast are dark green; the belly is green; the underwing coverts are blue; the eye is brown; bill is pale grey; legs and feet are grey.  Both sexes have a red   frontal band across the top of the bill, as do the wheatbelt hybrids. The wheatbelt or yellow-fronted Twenty-eights as they are often called have the same colourings and markings, except the belly is yellow grading to a pale green towards the vent.
Immatures of both the Twenty-eight and the wheatbelt hybrid are duller than the adults with a brown hue about the head. The Twenty-eight has a tri-syllabic call, sounding like 'twenty-eight', as the last note is higher in pitch than the first two. This call has given rise to their common name.
The Port Lincoln parrot is also known as Bauer's parrakeet, Banded parrot or the Yellow-naped parrot, although these names are not widely used.
Once again the sexes are similar with the male being slightly larger with a broader head. They are 37cm in length, including 19cm of tail. The head is dull black; lower ear coverts are violet-blue; narrow yellow collar on the neck; back and wings are green; outer web of primary feathers are green, becoming blue towards the tips; the lateral feathers are blue edged with pale blue; the throat and breast are blue green and the belly yellow changing to a yellow green as nears the vent and undertail coverts.  Underwing coverts are blue; the eye is brown; the bill pale grey and the legs and feet are grey. Neither the male or female Port Lincoln has a red frontal band although some individual birds may have a small red spot above the bill. This is due to interbreeding, as the Twenty-eight, the wheatbelts and the Port Lincoln will readily hybridise. This is most noticeable in large numbers of trapped birds that dealers have on hand at times.
Immature Port Lincoln's are once again duller than the adults with the head having a brown hue.
The contact call is a high pitched whistling note, repeated rapidly several times. The alarm call is harsh and metallic, being very similar to that of the Mallee ringneck.

The Twenty-eight and Port Lincoln breed from August to February, mainly in central and southern Australia. Birds in northern Australia are known to start nesting as early as June, but this often depends on the rainfall. They often double brood in the wild although I have rarely heard of them double brooding in captivity.

Mating

There is a great activity at the start of the breeding season as the pair inspect every hole and hollow in the branches of a living or dead     eucalyptus tree, chattering incessantly and wagging their tails.  Once a breeding pair have selected a hollow they defend it vigorously against other parrots.
During the mating display, the courting male crouches in front of the female, squares his shoulders and wings and vibrates them slightly, with his tail fanned and moving quickly from side to side. While doing this he chatters constantly.

Nesting

They nest in a hollow limb of a eucalyptus tree, laying four to seven (usually four), rounded, white eggs 31x25mm in size.  The bottom of the   hollow is lined with wood dust as a soft bed for the eggs. Hens sit for 21 days and young fly after 30 days.

Distribution 

The Port Lincoln is widely distributed on the west coast of South  Australia around Kimba, north to Alice Springs, west from Alice Springs to the Western Australian coast, and the whole of WA below that line, except the south-west corner.  They are most common in most types of lightly     timbered country, from eucalypt woodland to mallee and dry acacia      scrubland of the central regions.
The Twenty-eight inhabits dense eucalyptus forests in the south-west of Western Australia.

Feeding

Twenty-eights and Port Lincolns feed on the ground or among the branches of trees and shrubs, eating a variety of seeds and plant food.

Behavior

These conspicuous birds are noisy and inquisitive. When disturbed they fly to a nearby tree, call excitedly and evaluate the danger before flying away. The alarm calls given by one bird quickly attracts others and soon the disturbance, be it a snake, goanna or other, is being investigated by a dozen or more chattering parrots.
Twenty-eights and Port Lincolns in an aviary have been known to be very aggressive towards their young when they have fledged and it is best to isolate the young as soon as they are independent. They have also been known to continually chase their young from the feed bowl, resulting in the death of the young birds.

Names

The Mallee ringneck parrot is also known as the Mallee parrot,   Ringneck parrot, Barnard's parrakeet or buln buln. It is often confused with its close relative, the Cloncurry parrot.  Both the Mallee ringneck and the    Cloncurry are the same size but their body colourings are different and more distinct than the Twenty-eight and Port Lincoln.

Size

They are approximately 34cm in length including 17.5cm of tail.

The male Mallee ringneck has an overall blue-green body plumage, a red frontal band above the beak and blue cheeks. They have a V-shaped brown-blue band extending from the eyes, back around the head, to meet a narrow yellow collar at the nape. There is an irregular band of orange-yellow across the belly, with the back and mantle a deep blue-black. The shoulders are yellow; the outer webs of the flight feathers blue, the underwing coverts also blue. The central tail feathers are blue with a faint edging of white. The eye is dark brown; bill is pale grey; feet and legs are grey.
The female is very similar to the male, but the back and mantle are a dark grey-green.  The hen is slightly smaller, especially in its head size.     Immature birds are duller than the female. The normal call sounds something like 'Kwink-Kwink-Kwink' and, when disturbed, the alarm call is a harsh     metallic shriek.
If feeding in branches or shrubs, they will utter a subdued chattering.
Mallees blend extremely well with their surroundings, either when feeding among the outer branches of eucalyptus or mallee or on the ground.

Diet

Their diet consists mainly of the seeds of grasses and herbs, fruit, blossoms, leaf buds and insects and their larvae, They are usually seen in pairs or family groups.

Breeding

The breeding season is usually August to January, but may be triggered by heavy rain. After choosing a hollow, the pair spend considerable time preparing it, lining the bottom of the hollow with decaying wood dust and making a shallow depression for the eggs.
The courting male crouches in front of the female, squares his  shoulders and wings and vibrates them slightly, with his tail fanned and  moving quickly from side to side. He also chatters constantly.
Four to six white eggs are laid (usually five); they are rounded and are 29x23mm in size. The female incubates the eggs for 20-21 days and the young leave the hollow after about 30 days.
While the female feeds in the early morning and late afternoon, the male sits in a nearby tree and warns of approaching danger.
The Mallee ringneck is common in mallee scrub, open woodlands
and in trees along watercourses and is distributed from the Murray Flats and Murray Mallee of South Australia, to the sunset country of north-west Victoria and western NSW. They are also seen in southern Queensland.
When seen in an aviary, their colouring may seem a bit ‘ordinary’, but when seen in the wild they are very impressive.
Soon after sunrise they leave their roosting perches, drink and move out to the feeding areas until mid morning. During the hottest part of the day they shelter in the trees or forage in the shade for seeds, fallen fruit and the like. Towards dusk they become active and feed and drink before roosting for the night.
The Cloncurry parrot is often confused with the Mallee ringneck in captivity. In the wild the Cloncurry parrot is restricted to the Selwyn Ranges in north-west Queensland.
The Cloncurry is of similar size and stature as the Mallee with the sexes alike.  The Cloncurry has a general plumage of pale green; no red   frontal band; a wide pale yellow band across the belly; the wing coverts are green; and the tail feathers get darker as they go down the tail, almost to a blue. The feet and legs are grey-brown. The female is paler than the male and slightly smaller. Immatures are duller than the adult birds and may posses a russet frontal band which disappears after a few months.
They have a call, courtship and mating habits very similar to a Mallee.  They seem to be a quieter bird and more docile among my collection of    ringnecks. The male Cloncurry is the clown of my collection, as he usually hangs upside down on the aviary roof and moves from one side to the other. He is usually seen to roost this way too.

Feeding

As far as feeding is concerned, ringnecks like a diet of small parrot mix comprising, for example, plain canary seed, grey sunflower (not black), hulled oats, pannicum, white millet and safflower.
They also relish a regular supply of fresh apple, silver beet, orange quarters, carrot, seeding grass, wheat, barley grass, millet sprays and sunflower heads.  Be careful with grass from the roadside as it may have been sprayed by the local Council.
They also enjoy almonds and nuts. Do not feed almonds that have been left to get damp. Make sure they are stored in a dry place and cracked when needed.

Housing

The floor of the aviary should consist of a sand or grit base, and cuttlebone and shellgrit should always be available. They also enjoy a fresh branch of mallee or other gum in the aviary every so often, chewing off the leaves and climbing all over it.
In all, I have found my collection of eight pairs of ringnecks, comprising three pairs of Port Lincolns, two pairs of Mallees, and one pair each of the Twenty-eight, wheatbelt hybrid and Cloncurry, a rewarding addition to my aviaries. One pair of Port Lincoln's are laying, and another is working their hollow, as is the pair of Mallees and the Cloncurry.  Most of my ringnecks are only 12 months old, so I am not over hopeful of achieving success just yet.
Some of mine are housed in adjoining aviaries, with heavy gauge 13mm mesh. I hope to have them in every second cage by next season as I build some more cages. My aviaries are all 2.4m deep, 0.9m wide and 2.1m high, except two which are 3.7m deep, 1.1m wide and 2.1m high. Their hollows are all 60-90cm long and hung at 45° angle, away from the afternoon sun.

Tuesday, October 23, 2012

Winter foods for birds

Chickadee rides a flower head while examining it for seeds
I’m fascinated with the nuthatches I’m seeing in the yard this year! Every time I fill the feeder, little nuthatches and chickadees are around to let me know they are doing their best to reach the end of my bottomless buffet of birdseed.

Goldenrod Gall
Birds are excellent food foragers. They don’t need a feeder to survive normally, but I enjoy watching them up close, so I provide them with ample seeds and suets. I also provide them with lots of trees, bushes, flowers, and vines that produce fruits, nuts and berries.

Bugs and bug larvae are also hidden but available if you know where to look. Sometimes they are buried in the fallen leaves or in the crevices of tree bark. Another tasty treat for bug eating birds is the Goldenrod Gall Fly larva. You may have noticed golf ball sized growths on dried goldenrod stems. Did you think maybe it was some weird seed pod development? It’s actually a spherical gall bed for larva to develop.

The female Goldenrod Gall Fly lays her eggs on young goldenrod stems in the spring. In about 10 days the eggs hatch and larva burrows down into the plant stem. The larva's saliva, which is thought to mimic plant hormones, results in the plant producing exaggerated plant growth or galls to provide the larva with both food and protection over the winter.

Woodpeckers, chickadees, titmice and nuthatches can peck into the galls to extract the tasty and energy rich larva inside. In some areas, it can be a very important food source for birds.

Related Articles:
- Birds of Michigan Field Guide http://bit.ly/pXv5ZN
- What’s the best suet for Michigan wild birds? http://bit.ly/nImz5g 
- How to have more colorful birds at your feeder http://bit.ly/qizlNh  
- How to Prepare Your Yard for Winter Birdwatching http://bit.ly/q93Men 
- What is the best bird feeder? http://bit.ly/qVr7i8

Monday, October 22, 2012

Bald Eagle







The bald eagle (Haliaeetus leucocephalus), America's national bird, is the only eagle unique to North America. The bald eagle's scientific name signifies a sea (halo) eagle (aeetos) with a white (leukos) head. At one time, the word "bald" meant "white," not hairless. Bald eagles are found throughout most of North America, from Alaska and Canada to northern Mexico. About half of the world's 70,000 bald eagles live in Alaska. Combined with British Columbia's population of about 20,000, the northwest coast of North America is by far their greatest stronghold for bald eagles. They flourish here in part because of the salmon. Dead or dying fish are an important food source for all bald eagles.


Eagles are a member of the Accipitridae family; which also includes hawks, kites, and old-world vultures.
   Scientists loosely divide eagles into four groups based on their physical characteristics and behavior. The bald eagle is a sea or fish eagle.
   There are two subspecies of bald eagles. The "southern" bald eagle, Haliaeetus leucocephalus leucocephalus, is found in the Gulf States from Texas and Baja California across to South Carolina and Florida, south of 40 degrees north latitude. The "northern" bald eagle, Haliaeetus leucocephalus alascanus, is found north of 40 degrees north latitude across the entire continent. The largest numbers of northern bald eagles are in the Northwest, especially in Alaska. The "northern" bald eagle is slightly larger than the "southern" bald eagle. Studies have shown that "northern" bald eagles fly into the southern states and Mexico, and the "southern" bald eagles fly north into Canada. Because of these finding, the subspecies of "northern" and "southern" bald eagles has been discontinued in recent literature.




Color -Both male and female adult bald eagles have a blackish-brown back and breast; a white head, neck, and tail; and yellow feet and beak.
    Juvenile bald eagles are a mixture of brown and white; with a black beak in young birds. The adult plumage develops when they are sexually mature. It takes about five years for their head and tail feathers to gradually turn white.
    The bald eagle is the only eagle confined to North America. There are no other large blackish-brown birds with a white head and tail in North American.







Size - A female bald eagle's body length varies from 35 to 37 inches; with a wingspan of 79 to 90 inches. The smaller male bald eagle has a body length of 30 to 34 inches; with a wingspan ranging from 72 to 85 inches. An eagle's average weight is ten to fourteen pounds. Northern birds are significantly larger than their southern relatives.

Eagles sit at the top of the food chain, making them more vulnerable to toxic chemicals in the environment, since each link in the food chain tends to concentrate chemicals from the lower link.
   A bald eagle's lifting power is about 4 pounds. They do not generally feed on chickens or other domestic livestock, but they will make use of available food sources. Bald eagles will take advantage of carrion (dead and decaying flesh). Because of its scavenger image, some people dislike the bald eagle. Other people do not care for powerful and aggressive birds. Still other people object merely on the grounds that it is a bird of prey, which kills other animals for food.  


Voice - Shrill, high pitched, and twittering are common descriptions used for bald eagle vocalizations. Eagles do not have vocal cords. Sound is produced in the syrinx, a bony chamber located where the trachea divides to go to the lungs. Bald eagle calls may be a way of reinforcing the bond between the male and female, and to warn other eagles and predators that an area is defended.

Eyesight - An eagle's eye is almost as large as a human's, but its sharpness is at least four times that of a person with perfect vision.

 Skeleton - It weighs about half a pound (250 to 300 grams), and is only 5 or 6 percent of its total weight. The feathers weigh twice that much. Eagle bones are light, because they are hollow. The beak, talons, and feathers are made of keratin.
bird skeleton

Habitat - Bald eagles live along the coast and on major lakes and rivers where they feed mainly on fish.

Longevity (life expectancy) - It's possible for bald eagles in the wild to live longer than thirty years, but the average lifespan is fifteen to twenty years. A captive eagle at West Stephentown, NY lived to be at least 48 years old.

Body Temperature - About 106 degrees Fahrenheit (41 degrees Celsius)

Eagles do not sweat, so they need to use other cooling methods such as perching in the shade, panting, and holding their wings away from their body.

Tolerance to cold temperatures - A bald eagle's skin is protected by feathers lined with down. Their feet are cold resistance, consisting of mostly tendon. The outside of the bill is mostly nonliving material, with little blood supply.

Golden eagles are larger than bald eagles in average height and wingspan, but there isn't much difference in average weight. One way to distinguish a golden eagle from an immature bald eagle is leg plumage. A golden eagle's legs are entirely feather covered; an immature bald eagle's lower legs are bare. As seen while in flight, juvenile golden eagles have white patches at the base of the primaries; the tail is white with a distinct dark terminal band. It takes four years to acquire adult plumage. Adult golden eagles are brown with tawny on the back of the head and neck; tail faintly banded.

Bald eagles are active during daylight hours (diurnal).

Fidelity - Once paired, bald eagles remain together for life. Although, if one dies, the survivor will not hesitate to accept a new mate.

The wings and soaring - An eagle's wings are long and broad, making them effective for soaring. To help reduce turbulence as air passes over the end of the wing, the tips of the feathers at the end of the wings are tapered so that when the eagle fully extends its wings, the tips are widely separated.


 To help them soar, eagles use thermals which are rising currents of warm air and up-drafts generated by terrain such as valley edges or mountain slopes. Soaring is accomplished with very little wing-flapping, enabling them to conserve energy. Long-distance migration flights are accomplished by climbing high in a thermal, then gliding downward to catch the next thermal where the process is repeated. Several eagles soaring in a thermal together is described as a "kettle of eagles."

   Bald eagles can fly to an altitude of 10,000 feet. During level flight, a bald eagle can achieve speeds of about 30 to 35 mph.

The tail - is very important for flight and maneuvering. While the bald eagle is soaring or gliding in flight, the tail feathers are spread in order to attain the largest surface area and increase the effect of thermals and up-drafts. The tail also helps to brake the eagle when landing and assists in stabilization during a controlled dive or swoop toward prey. The strength of the feathers and the follicles holding the feathers is quite impressive while watching the tail move back and forth and up and down during maneuvers.

Bald eagles have 7,000 feathers. Eagle feathers are lightweight yet extremely strong, hollow yet highly flexible. They protect the bird from the cold as well as the heat of the sun, by trapping layers of air. To maintain its body temperature an eagle simply changes the position of its feathers. While an eagle suns itself on a cold morning, it ruffles and rotates its feathers so that the air pockets are either opened to the air or drawn together to reduce the insulating effect. Feathers also provide waterproofing and protection, and are crucial for flight.



   






Feather structure makes pliability possible. Overlapping feathers can form a dense covering, which the birds can open or close at will. The bald eagle has several layers of feathers, each serving a different function. Under the outer layer of feathers is an inner layer of down or smaller feathers. The interlocking of feathers is an astonishing design of nature. 
   Birds puff up their feathers for various reasons. They puff them up while preening; to insulate themselves to changing temperatures; when they're relaxed; to make themselves appear larger when threatened; and when they're ill.
   The feathers enable eagles to live in extremely cold environments. Eagles do not have to migrate to warmer areas each year to fulfill temperature requirements, they migrate to available food supplies.
   A lone eagle feather is believed to convey great power. North American Indians incorporated the eagle's primaries and tail feathers into their ceremonies and legends.   Use of feathers permit.

Respiratory system - Eagles have an external naris on both sides of their beak. A bald eagle never reaches speeds that would interfere with normal breathing. An eagle's lungs and air sac system are adequate for its size. Air moves in through the lungs and on into the air sacs before moving back through the lungs and out again. Air passes through the lungs twice with each breathing cycle - twice that of mammals. More about the respiratory system of birds

Beak - The hook at the tip is used for tearing. Behind the hook, the upper mandible, the edge sharp enough to slice tough skin, over laps the lower, creating a scissors effect. A bald eagle's beak is a strong weapon, but is also delicate enough to groom a mate's feathers or feed a small portion of food to a newly hatched chick. The beak of a female eagle is deeper (distance from top to chin) than the beak of a male.  


The beak and talons grow continuously, because they are made of keratin, the same substance as our hair and fingernails. The beak of a captive eagle is not warn down naturally, so must be trimmed annually.

Talons - Talons are important tools for hunting and defense. Eagles kill their prey by penetrating its flesh with their talons.
   Eagles can open and close their talons at will. If an eagle is dragged into the water by a fish too large for the eagle to lift, it is because the eagle refuses to release it. In some cases this is due to hunger. An eagle might drown during the encounter with the fish or if it's unable to swim far enough to reach shore.

Above all other birds it is the soaring eagle, with its size and weight, that gives the most abiding impression of power and purpose in the air. It advances solidly like a great ship cleaving the swells and thrusting aside the smaller waves. It sails directly where lesser birds are rocked and tilted by the air currents.

   Bald eagles were officially declared an endangered species in 1967 in all areas of the United States south of the 40th parallel, under a law that preceded the Endangered Species Act of 1973.
   Until 1995, the bald eagle had been listed as endangered under the Endangered Species Act in 43 of the 48 lower states, and listed as threatened in Wisconsin, Minnesota, Michigan, Washington and Oregon. In July of 1995, the US Fish and Wildlife Service upgraded the status of bald eagles in the lower 48 states to "threatened."
   On June 28, 2007 the Department of Interior took the American bald eagle off the Endangered Species List. The bald eagle will still be protected by the Migratory Bird Treaty Act and the Bald and Golden Eagle Protection Act. The Bald Eagle Protection Act prohibits the take, transport, sale, barter, trade, import and export, and possession of eagles, making it illegal for anyone to collect eagles and eagle parts, nests, or eggs without a permit. Native Americans are able to possess these emblems which are traditional in their culture.

Saturday, October 20, 2012

Owl





Introduction

Owls are a world-wide order of birds known as Strigiformes and the 216 species range in size from the tiny, sparrow size, Elf Owl to the Eurasian Eagle Owl which has a wing span of nearly 2 metres and can weigh almost 5kg. They are a group of predatory birds, characterised by large forward facing eyes surrounded by a facial disk of short stiff feathers and an upright posture. A large proportion of owls are nocturnal. They occupy an equivalent niche to the diurnal birds of prey such as hawks, falcons, eagles and buzzards but they are not actually related. The resemblance to the day time birds of prey is an example of convergent evolution, where both groups have independently evolved several features such as the hooked beak and talons. Owls are all very closely related to each other, much more so than, for instance, the diurnal raptors which include birds as dissimilar as vultures, secretary birds, falcons etc. Even so, owls are separated into two fairly distinct families.

The first family is the Tytonidae which is made up of 17 species of barn and grass owl, and one species of Bay Owl. Members of this family are quite distinct from other owls and possess several differences. The most obvious external ones being the heart-shaped rather than round facial disk, the longer skull and beak, longer legs, longer and more pointed wings and a forked tail. Grass Owls come from Africa, South East Asia and Australia and are very similar to Barn Owls but have longer legs.

All of the other 198 owls are in the family Strigidae.

The collective noun for owls is a “Parliament”.

The Barn Owl is protected in the same way as any other wild bird, in that it is illegal to injure, kill or take one from the wild. It also has added protection in that, during the breeding season, it is illegal to disturb the nest sites. That means that if a bird is actually sitting on eggs or there are unfledged babies in the nest site it is illegal to disturb them in any way. If that nest site is in a building that is going to be developed, building work has to be delayed until the young have fledged.

Food and Hunting











All owls are predators and the size of the prey is generally reflected by the size of the owl. The Elf and Pygmy Owls prey on a variety of insects, spiders and other invertebrates, although, some are quite voracious and can take birds as large as themselves. Eagle Owls, at the other extreme have been known to take such formidable prey as Golden Eagles and a Roe Deer of 13kg as well as foxes, herons, domestic dogs and there is apparently a report of a large Siberian Eagle Owl taking a ¾ grown wolf!



Hunting, normally, is performed in two different ways. The first is perch hunting, where the bird literally sits and waits on a suitable perch until a prey item is located. The other technique is flight hunting where the owl slowly quarters the ground from a low altitude, looking and listening for prey and diving down when food is detected. The length of the wings is normally a good indication of the preferred method of hunting - short wings for perch hunting and long wings for flight hunting.



Most owls are opportunists and virtually anything that moves is fair game. Some species are more specialised feeders, in particular the Fish and Fishing Owls. These are two genera of owls, one from Asia and the other from Africa whose members feed mainly on fish, amphibians and aquatic invertebrates, snatched from beneath the water surface.

No other species are quite so specialised but some have a preference for particular prey. The Milky Eagle Owl of Africa feeds on a wide variety of prey, but where the ranges overlap it seems particularly partial to hedgehogs. The Eurasian Eagle Owl would appear to have a vendetta against other birds of prey, especially other owls. In some areas they form 10% of the bird’s diet, which is much greater than one would expect from chance.

Eyesight

Because of their predominantly nocturnal tendencies, owls have evolved several physical adaptations which facilitate catching prey in the dark. All owls have large forward facing eyes giving good stereoscopic vision, vital for judging distances. Indeed, owls have the most forward facing eyes and hence the best stereoscopic vision of all birds. In smaller species the head often appears flattened so that the eyes can be as widely spaced as possible to increase the stereoscopic effect. This is often further enhanced by bobbing or weaving the head to give a differing perspective known as the parallax effect.
The eyes are very large, those of a Snowy Owl weighing as much as our own. They are modified in nocturnal species to improve sensitivity in low light intensities. They are tubular, rather than round, giving a relatively large cornea in proportion to the overall size of the eye and enabling more light to enter the eye. The light passes through the pupil (which can be closed by the iris to a small pinprick in bright light or opened so wide that virtually no iris is visible at night) to the lens. This is large and convex, causing the image to be focused nearer to the lens hence retaining maximum brightness. One drawback is that owls are long sighted and cannot focus on objects which are too close. Tactile bristles around the beak partially compensate for this. The tubular shape also gives a comparatively large retina size which is packed full of light sensitive rods, about 56,000/square mm. in the Tawny Owl. These rods are far more sensitive than cones at low light levels. The phenomenal light gathering properties of the owls eye is further enhanced in many species by a reflective layer behind the retina, called the tapetum lucidum, which reflects back onto the rods any light that may have passed through the retina without hitting one the first time. Tawny owls would appear to have the best developed eyes of all the owls, indeed of all vertebrates, being probably about 100 times more sensitive at low light levels than our own.
As well as rods, all owls possess colour sensitive cones in their eyes. Although having fewer light sensitive cones than humans, they can probably detect colours to some extent. They are certainly not blind in daylight and some, like the Eagle Owl, have better day time vision than us. Our night time vision, however, is better than some diurnal Pygmy Owls.

Owls are unable to move their eyes in the sockets because of the size and tubular shape. To compensate, they have a deceptively long flexible neck which enables them to turn their head 270° in either direction horizontally and at least 90° vertically.

Breeding


No owl can be said to build its own nest in the proper sense of the word. Burrowing Owls may extend an already existing burrow, and some of the large owls may scratch a slight depression or scrape in loose earth but nothing that compares with the marvels produced by some other birds. Nest sites vary but tree hollows and cavities are the preferred site for many species. The Elf Owl nests in holes in Sanguaro cactuses made by the Gila Woodpecker, the Burrowing Owl as mentioned in animal burrows, Grass owls trample tunnels and nest chambers in long grass, whilst larger species scratch a scrape or use old stick nests of crows, pigeons or diurnal birds of prey. The American Great Horned Owl often drives out quite large raptors such as red-tailed buzzards and takes over their nests. Tawny Owls often use old squirrel drays, and Barn Owls in Africa use the giant stick structures made by Hammerkops (a stork like bird) occasionally nesting communally. Many species can be encouraged to use nest boxes and they may even be used in preference over natural sites.


Many owls are quite territorial, especially during the breeding season, sometimes even other owls species are not tolerated, at the other extreme some species will defend the nest site its self but will share hunting habitat.

Breeding seasons are always geared so that rearing chicks coincides with the peak availability of food, this is not always when prey is most numerous but when it is able to be caught in increased numbers. This may be as a result of decreased vegetation cover, or when the prey are more active or vocal say in defence of their territories allowing them to be caught more easily. In some species this often means that the eggs are laid very early, some times with snow still on the ground, this also gives the relatively slow growing young more time to learn how to hunt more efficiently before the following winter.

All owls lay white eggs, which suggests that they all evolved from a hole nesting ancestor. Elaborate markings to conceal the eggs from predators aren't needed in dark holes indeed the whiteness may make them more visible to the parents.

The number of eggs laid varies from species to species, year to year and between individual birds. In general larger birds lay fewer eggs, and birds from tropical regions lay fewer than birds from more extreme latitudes. In temperate and sub-arctic regions some species like the Snowy Owl the Short-eared Owl and the Barn Owl can increase the size of the clutch as prey availability increases, in years when the lemming or vole populations crash, breeding may be abandoned totally.

Owl eggs are relatively spherical to a greater or lesser extent. In most species the female starts incubating as soon as the first egg is laid. The eggs are laid at intervals of at least a day, often more, resulting in what is known as asynchronised hatching, where the eldest chick can be up to 2 weeks older than the youngest. The means that each chick reaches its peak food demand period at different times and so spreading the load. In lean years the oldest and therefore strongest chicks at least will survive, the younger chicks, once dead, may even be utilised to feed the others.

During incubation, and until the smallest chick is large enough to maintain its own body temperature, all the food is provided by the male, the female rarely leaving the nest site. She dispatches the food and feeds the chicks small slivers until they can swallow the prey whole, she then helps the male with the hunting.

The age of fledging varies greatly and some species even remain in the area until the following year. Gradually the young learn to hunt, often starting on insects or food brought in by the parents, which may still be alive. Most species are independent by their first winter and in many cases the young are actively driven away by their parents prior to this.