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"Mysteries of Migration" slideshow/lecture tomorrow night

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  • Kate Marianchild
    Please pass this along to your friends! Mysteries of Migration: Slideshow and Lecture by Ron Levalley by Kate Marianchild Bird migration has mystified humans
    Message 1 of 1 , Oct 17, 2007
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      Please pass this along to your friends!


      Mysteries of Migration:
      Slideshow and Lecture by Ron Levalley

      by Kate Marianchild

      Bird migration has mystified humans since we acquired a sense of
      wonder. Birds disappeared in the fall and arrived in the spring, and no
      one had any idea where they had been in the meantime. Ancient people
      would have been astonished to know that the beautiful flyers that came
      and went twice a year were more familiar with distant and exotic lands
      than they were. As humans began traveling long distances across the
      world by ship and by air we gained knowledge of the destinations of
      migrant birds, and over the last several decades we have learned that
      birds navigate by the sun, the stars, magnetic fields, and smells. But
      no one has ever known exactly what happens during migration: do the
      birds stop to eat or drink? if they eat, what do they eat? do they
      sleep? do they fly a straight course or meander? how high do they fly?
      The mystery has always been compounded by the fact that many birds
      migrate exclusively at night.

      Well, exciting new developments are on the wing. With the use of tiny
      transmitters and satellites scientists can now sit in front of computer
      screens and watch migrating birds all around the world as they eat,
      sleep, and veer off course to feed on islands in the middle of the
      ocean. Ron LeValley, an eminent biologist, ornithologist, and
      photographer, will deliver a slideshow lecture on this fascinating
      subject on Thursday, October 18, at the Ukiah Civic Center at 7 p.m.
      LeValley´┐Żs talk will focus on seabirds that migrate extraordinarily
      long distances and the challenges facing small-population migrants.
      This Peregrine Audubon Society event is free to the public but
      donations will be gratefully accepted.

      It is a common and comfortable myth that migrating juvenile birds are
      led to their wintering grounds by their parents. In fact it is only
      among geese, cranes, and some other fresh-water waterfowl that such
      parental shepherding occurs. One of the birds that LeValley will talk
      about is the Bristle-thighed Curlew, a long-legged shorebird that nests
      in a small area of western Alaska called Beringia. The adult females of
      the species desert their chicks as soon as the chicks can fly, at four
      weeks old, and fly to a food rich area in the Yukon where they fatten
      up for their upcoming migration. The males soon take off as well,
      leaving the chicks to frantically feed and practice flying on their
      own. In late August and early September the adults begin their
      migration, the endpoint of which is sometimes 5,000 miles away on
      remote islands in the South Pacific. They make the flight non-stop, as
      they lack waterproof plumage and therefore cannot rest on the water.
      The juveniles leave a few weeks later and fly the same distance without
      adults to guide them, relying on genetically programmed cues. No one
      knows exactly how either the adults or juveniles find their tiny island
      destinations in the vast Pacific, but most arrive safely.

      Another bird we will learn about is the Laysan Albatross, a seabird
      that nests on the northwest Hawaiian islands and flies several thousand
      miles to the coasts of California and Alaska to collect oil-rich squid
      and other fish for its chicks. LeValley will also bring us up to date
      on avian migration records. The Arctic Tern, which migrates 22,000
      miles round trip from the Arctic Circle to Antarctica, may now be
      challenged for its title as the longest-distance migrant in the world.

      Ron LeValley is founder and senior biologist of Mad River Biologists in
      McKinleyville. He is the California coordinator for the Pacific Coast
      Joint Venture, a public/private partnership funded by the North
      American Wetlands Conservation Act to promote conservation. LeValley
      lectures all over the western United States at Audubon meetings, bird
      festivals, and ornithological conferences, where he is frequently the
      keynote speaker. He is also a founding member of the Mendocino Coast
      Photographer Guild and Galley in Fort Bragg, where he displays his
      nature and wildlife photographs. His passion for the natural world is
      rivaled only by his desire to share that passion.

      The Ukiah Civic Center is at 300 Seminary Avenue. From 101 take Perkins
      west to State Street (3rd light). Go left on State Street and turn
      right on Seminary. Take Seminary to the end. To join Peregrine Audubon
      Society and receive a newsletter with articles and announcements about
      programs and field trips, please send $15 to PAS, P.O. Box 311, Ukiah,
      CA 95482.




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