[va-richmond-general] And another one!

  
http://news.yahoo.com/s/space/20050623/sc_space/birdswarningchirpsrevealsurprisingsmarts

   
  Bird's Warning Chirps Reveal Surprising Smarts 
  Robert Roy Britt
  LiveScience Senior Writer
  LiveScience.com Thu Jun 23, 4:58 PM ET 

  Birds squawk and chirp to attract mates and warn of danger. But much of their 
intelligent chatter has until now eluded human comprehension.

  The black-capped chickadee not only warns its flock of danger but also 
communicates the predator's size and relative threat, a new study finds.

  All with a familiar chick-a-dee-dee-dee -- plus a few more dees.


  Imminent danger? 


  A cat on the ground might elicit five or 10 dees. But something closer and 
capable of an aerial attack could generate nearly two dozen closing notes.


  "With something really dangerous, such as a pygmy-owl perched near some 
chickadees in our aviary, we heard as many as 23 added dees," said Chris 
Templeton, a biology doctoral student at the University of Washington and lead 
author of the study.


  The acoustic signatures of the calls change too, in ways humans can't notice.


  The results are detailed in the June 24 issue of the journal Science.


  Your backyard 


  Black-capped chickadees are common in much of North America, and might be in 
your backyard right now, according to scientists at Cornell University. They 
are about 5 inches long and are very active. Look for a black cap and white 
cheeks. 


  Scientists had already described their call as one of the most complex in the 
animal kingdom. A chickadee can tell of individuals it spots or entire flocks 
it recognizes, previous studies showed.


  The new research was done in an outdoor, semi-natural aviary with 15 live 
predators perched or on leashes. 


  Small but dangerous 


  Chickadees recognize a predator's threat status based on its size and 
agility, the study found. And, they know, bigger isn't always badder. Like 
Tweetie Bird taunting Sylvester the Cat, they can virtually ignore some 
not-so-dangerous predators. 


  "A pygmy-owl is more dangerous to a chickadee than a great horned owl that 
has a large hooked beak and big talons," Templeton explained. "A great horned 
owl going after a chickadee would be like a Hummer trying to outmaneuver and 
catch a Porsche."


  The test chickadees paid no attention to a nearby and harmless bobwhite 
quail, suggesting the songbirds also recognize various species.


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