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

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NOT NOW

storia uccelliStoria Naturale degli Uccelli Trattata con Mmetodo e Adornata di Figure Intagliate in Rame e Miniate al Naturale. Ornithologia methodice digesta atque iconibus aeneis ad vivum illuminatis ornate
Saviero Manetti (1723-1784) (editor)
Lorenzo Lorenzi (act. c. 1760) and Violante Vanni (c. 1732-1776)                     (artists and engravers)

When To Prune Trees: NOT NOW

The idea that we can keep pruning, if we’re careful, is wishful thinking.
When arborists or tree trimmers tell you it’s OK to prune in April, May or June because they will keep an eye out for nests, the blunt translation is: “Forget the birds.”
Although rules exist that require tree workers to stop cutting when active nests are discovered, a nest revealed is a nest imperiled.

In short, only one valid excuse exists for spring or early summer pruning: a danger in which a potentially falling tree threatens life or property.

California has a long nesting season.
Hummingbirds have been broody since January and will remain so for some time.
Think of them when you tell your gardener to leave the hedges, camellias and hibiscuses alone.
Bushtits, swallows, wrens, woodpeckers, phoebes and finches are either sitting on eggs or constructing nests.
Think of them, then put off termite work, gutter repair and tree thinning.

Also: Nothing else does the kind of job that birds do controlling insects.
No pesticide matches their safety for humans.
If your hibiscus has whitefly, it’s probably because constant pruning keeps out the flocks of bushtits that would have devoured the insects.
If unwelcome caterpillars are wreaking havoc on your vegetables, rethink letting the garden crews with buzz saws evict the finches that would otherwise have eaten the pests.
If rats appear on your telephone wires at night, you don’t need poison. You need a hawk.

For trees and shrubs, water deeply and occasionally, say once a month, to avoid the stress of drought.

Years ago, in a bid to stop the routine destruction of nesting grounds in Southern California, the Los Angeles Audubon Society produced the Guide to Bird-Friendly Tree and Shrub Trimming and Removal.
Online versions are available in Spanish and English.


http://latimesblogs.latimes.com/…/…/when-to-prune-trees.html