The Journeys of Birds

migration19th Century
Museum of Modern Art, New Delhi

At least 4,000 species of bird are known to be regular migrants, which is about 40 percent of the total number of birds in the world.
(Although this number will likely increase as we learn more about the habits of birds in tropical regions.)

Birds can reach great heights as they migrate.
Bar-headed Geese are the highest-flying migratory birds, regularly reaching altitudes of up to five and a half miles above sea level while flying over the Himalayas in India.
But the bird with the record for the highest altitude ever is the Ruppel’s Griffon Vulture.

The Arctic Tern has the longest migration of any bird in the world. They can fly more than 49,700 miles in a year, making a round trip between their breeding grounds in the Arctic and the Antarctic, where they spend their winters.
Over a lifespan of more than 30 years, the flights can add up to the equivalent of three trips to the moon and back.

The Northern Wheatear travels up to 9,000 miles each way between the Arctic and Africa, giving it one of the largest ranges of any songbird.
What makes this an especially amazing feat is that the tiny bird weighs less than an ounce.

The Bar-tailed Godwit has the longest recorded non-stop flight, flying for nearly 7,000 miles, over eight days, without food or rest.

To prepare for the extremely taxing effort of migration, birds enter a state called hyperphagia, where they bulk up on food in the preceding weeks to store fat, which they’ll later use for energy on their long journeys.
Some, like the Blackpoll Warbler, almost double their body weight before flying 2,300 miles for 86 hours without stopping.

Even birds that don’t fly migrate.
Emus, the large Australian birds, often travel for miles on foot to find food, and many populations of Penguins migrate by swimming.

Migration can be terribly dangerous for birds, and they often don’t make it back to their starting point.
Sometimes natural occurrences like harsh weather play a role, but human activities are the cause of many deaths.
In the United States alone, up to one billion birds die each year from window collisions,
seven million from striking TV and radio towers.

http://www.audubon.org/birds
http://www.audubon.org/conservation

The Peacock

grassi peacockThe Sketchbook of Giovannino de’ Grassi  (Milano, circa 1350 – 1398)

Choices

tree bullfinch durer

Three Studies of a Tree Bullfinch, Albrecht Dürer (1471 – 1528)

I go to the mountain side
of the house to cut saplings,
and clear a view to snow
on the mountain. But when I  look up,
saw in hand, I see a nest clutched in
the uppermost branches.
I don’t cut that one.
I don’t cut the others either.
Suddenly, in every  tree,
an unseen nest
where a mountain
would be.

for Drago Štambuk
by Tess Gallagher

Stork

Albrecht Dürer (21 May 1471 – 6 April 1528) German painter, printmaker, engraver, mathematician, and theorist

Albrecht Dürer (21 May 1471 – 6 April 1528)
Painter, printmaker, engraver, mathematician, and theorist.

Storks have no syrinx and are mute.
They use soaring, gliding flight, which requires thermal air currents, to conserve energy.  Photographs of storks by Ottomar Anschütz inspired the design of Otto Lilienthal’s experimental gliders of the late 19th century.
Their nests sometimes grow to more than six feet in diameter and ten feet in depth.
Storks were thought to be monogamous which is partly true. They may change mates after migrations, and may migrate without a mate. They tend to be attached to nesting places as much as partners.
Their size, serial monogamy, and faithfulness to an established nesting site contribute to the prominence of storks in culture and in mythology.
W.

Steal Into the Pleached Bower

Schnorr_von_Carolsfeld_-_Entwurf_für_das_Dekor_einer_Meißener_Vase
Julius Schnorr von Carolsfeld (1794 – 1872)

 


http://www.guardian.co.uk/science/neurophilosophy/2012/jan/19/1


Chickens, thrushes, pigeons and parrots have all been shown to be sensitive to various illusions, and–lacking the peacock’s tail–males of many species display themselves to females at a particular angle and distance with deliberate intention, because–for instance–the females may prefer males with larger coloured patches on their bodies.

Male Great bowerbirds spend many months building true marvels of complex architecture which consist of a thatched twig tunnel forming an avenue approximately half a metre long, opening out onto a court whose floor is covered with bones, shells and stones.
When a potential mate steps into the avenue, the male stands in the court just by the avenue’s exit, displaying to her the colourful flotsam and jetsam he has collected, one piece after the other.

They are  magicians – the bowers they build are like a house of illusions, with visual tricks that manipulate females’ perceptions.
The objects covering the floor of the court are arranged so that they increase in size as the distance from the bower increases. Thus, when the female is standing in the avenue all of the objects in the court appear to be the same size from her point of view, so she may perceive the court as being smaller than it actually is, and the male to be bigger.

Scientists reversed the objects by placing the larger objects closest to the bower and the smaller ones further away, and found that the birds corrected the  disarray very quickly.
In all cases the pattern was almost identical to the original within two weeks.

The birds go to great lengths examining their work and rearranging objects to make the pattern as even as possible.
“Males spend most of their time on the bower going into the avenue and looking out, then moving objects, going back into the avenue, and so on. They sometimes fix the twigs in the walls, too.”

During his courtship display, the male waves his treasures towards the female, causing their apparent size to increase.
The more time a female spends in a bower, the more likely she is to mate with its builder so holding her attention longer is important.

http://what-when-how.com/birds/satin-bowerbird-birds/
After carefully constructing a twig avenue on the forest floor; the Satin bowerbird chooses decorations, arranging them around the sunny northern entrance.
He favors blue, but may use yellowish-green ornaments, like the female’s plumage.
If anything outside his color scheme (such as a white flower) falls onto the bower, he’ll quickly remove it.

The male bowerbird is one of the few birds known to use tools. He forms soft bark or other plant fiber into a sponge to absorb a mixture of saliva and bushfire charcoal, holding the sponge in his bill to daub the bower’s inner walls. He also paints the twigs by rubbing them with the juice of pulped blueberries.

The Vogelkop gardener bowerbird of New Guinea builds an astonishing courting place — a hut up to 5′ wide with a moss front garden on which he arranges flowers and fruits. MacGregor’s bowerbird builds a 2′-high twig maypole ringed by a circular dance floor because the brightly colored male dances around his bower to entice a female to enter.

Rival males steal trinkets from an unguarded bower and may even demolish it if the owner doesn’t return in time.
The bowerbird is an accomplished mimic whose repertoire has been known to include the mew of a cat.

All male bowerbirds decorate their bowers lavishly with flower petals and sparkly manmade trash: plastic bottle caps, straws, paper, jewelry, teaspoons …

Chief threats to the bowerbird’s future are forest clearance and shooting by fruit growers, which has led to extermination in some areas.

 

Reference: Kelley, L. A & Endler, J. A. (2012). Illusions Promote Mating Success in Great Bowerbirds. Science, DOI: 10.1126/science.121

Is Grammar Unique to Human Language?

the strawberry thief
While birdsong has long been known to share similarities with human language, the ability to convey different bits of information by simply rearranging word order was thought to be exclusively human.

This study revealed that Bengalese finches can learn grammar and, furthermore, that their grammatical abilities involve a specific part of the brain region distinct from other brain regions involved in singing. This is similar to what neuroscientists understand about human language processing.

If the tweets of birds can be roughly likened to strings of human words, and if bird brains process songs in a way similar to how human brains process language, future research may tackle whether these animals possess other cognitive abilities once thought to be singularly characteristic of human intelligence.

About the Author: Danielle Perszyk is a social neuroscience researcher at the Yale Child Study Center, where she studies autism using electrophysiological methods. At Williams College, studying cognitive science and neuroscience, she wrote a thesis on the neural mechanisms underlying syntax in birdsong. She is interested in the mind from an evolutionary perspective and is pursuing her PhD in cognitive psychology.

http://blogs.scientificamerican.com/guest-blog/2011/10/28/are-birds-tweets-grammatical/

Strawberry Thief is one of William Morris’s most popular repeating designs for textiles. It takes as its subject the thrushes that Morris found stealing fruit in the kitchen garden of his countryside home, Kelmscott Manor, in Oxfordshire. To print the pattern Morris used the ancient and painstaking indigo-discharge method he admired above all forms of printing.

Blue Heron

Mark Catesby (1682/83 – 1749)

 

 

Published in: on August 15, 2011 at 6:10 pm  Leave a Comment  
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Lyrebirds – Accidental Historians

Archibald James Campbell 1853-1929. Silver gelatin print.

Nature’s Living Tape Recorders May Be Telling Us Secrets
Robert Krulwich

In 1969, Neville Fenton, an Australian park ranger, recorded a lyrebird singing a song that sounded very much like a flute, a flute being played by a human. After much sleuthing, Mr. Fenton discovered that 30 years earlier, a farmer/flute player had lived near the park and played tunes to his pet lyrebird. That lyrebird downloaded the songs, then was allowed to live wild in the park.

Phrases from those flute songs apparently became part of the local lyrebird songbook. A scholar named Norman Robinson figured out that the songs wild lyrebirds were singing in 1969 were modified versions of two popular tunes from the 1930s, “The Keel Row” and “Mosquito’s Dance.”

When the BBC’s David Attenborough ran into a lyrebird deep in the Australian woods, the bird not only sang the songs of 20 other forest birds, it also did a perfect imitation of foresters and their chainsaws, who apparently were getting closer. That same bird made the sound of a car alarm.
These birds were, in effect, recording the sounds of their own habitat destruction.

http://www.npr.org/blogs/krulwich/2011/04/26/135694052/natures-living-tape-recorders-may-be-telling-us-secrets?ft=1&f=1007