Thought some of you on the listserve might find this interesting.
DaveR/Breaks
----- Original Message -----
From: GARY RAINES
To: David & Susan Raines
Sent: Wednesday, June 08, 2016 9:59 AM
Subject: For a bird lover
From delanceyplace.com:
Today's selection -- from Birdology by Sy Montgomery. The exquisitely delicate
hummingbird is the lightest bird in the sky, but is in some respects the most
powerful. One species of hummingbird can dive at a rate of sixty-one miles per
hour.
"Unlike our thick, marrow-filled bones, most birds' bones are hollow. Even
their skulls are scaffolded with passageways for air. Their feather shafts are
hollow, and the feathers themselves, like strips of Velcro, are interlocking
barbules for catching air. Their bodies are filled with air sacs, which
originate in, and function, in part, as extensions of the lungs. No fewer than
nine of these filmy bladders fill the tiny body of a hummingbird: one pair in
the chest cavity; another under each shoulder blade; another pair in the
abdomen; one under each wing; and one along the neck.
A female ruby-throated humming bird hovering in mid-air
"Hummingbirds are the lightest birds in the sky. Of their roughly 240 species,
all confined to the Western Hemisphere, the largest, an Andean 'giant,' is only
eight inches long; the smallest, the bee hummingbird of Cuba, is just over two
inches long and weighs a single gram.
"Delicacy is the trade-off that hummingbirds have made for their unrivaled
powers of flight. Alone among birds, they can hover, fly backward, even fly
upside down. For such small birds, their speed is astonishing: in his courtship
display to impress a female, a male Allen's hummingbird, for instance, can dive
out of the sky reaching sixty-one miles per hour, plunging from fifty feet at
a rate of more than sixty feet per second -- and pulling out of his plunge, he
experiences more than nine times the force of gravity. (Adjusted for body
length, the Allen's is the fastest bird in the world. Diving at 385 body
lengths per second, this hummer beats the peregrine falcon's dives at 200 body
lengths per second -- and even bests the space shuttle as it screams down
through the atmosphere at 207 body lengths per second.)
Rufous hummingbird
"Hummingbirds' wings beat at a rate that makes them a blur to human eyes, more
than sixty times a second. For centuries, people deemed hummingbird flight
pure magic. Until the invention of the stroboscope, scientists could not
understand how hummingbirds hover. With a flash duration of one
hundred-thousandth of a second, the stroboscope finally revealed the motion of
wings that had been too fast for other cameras to capture.
"Hummingbirds are less flesh than fairies. They are little more than bubbles
fringed with iridescent feathers-air wrapped in light. ... Feathers are among
the most complex structural organs found in nature. Nothing of comparable
dimension is stronger. They are made of keratin, the same as a humans
fingernails, a horse's hooves, and a rhino's horn-but the keratin in feathers,
due to a difference in molecular structure, is even tougher."
Sent from my iPhone
