[obol] Brood Parasitism

[Wayne Hoffman]

Back in the late 1940s two short papers were published in the Condor about "foreign" eggs in California Gull nests.  The authors were watching gull colonies, making behavioral observations, and watched adult gulls return to thier incubating mates and disgorge whole eggs that they had swallowed.  The incubating mates sometimes, istead of breaking and eating the eggs, behaved as if they had rolled out of thier nests, and pulled them in under themselves.  Egg retrieval is a very stereotyped behavior in gulls, well-studied by Nioko Tinbergen and his associates back in the 1940s or 1950s.

Wayne
  ----- Original Message ----- 
  From: Larry McQueen 
  To: jcholleyjr at yahoo.com ; obol at oregonbirdwatch.org 
  Sent: Friday, July 25, 2008 10:14 AM
  Subject: Re: [obol] Brood Parasitism


  Jack,

   

  I think this is quite likely.  I once found a Snowy Egret egg in a clutch of California Gull eggs in a gull colony along the Snake River in Idaho.  I can't imagine the gull raising the egret, however!  Green Herons probably use old crow nests as a starter kit, as they both nest in the canopy of street trees.  

   

  Larry

   


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  From: obol-bounces at oregonbirdwatch.org [mailto:obol-bounces at oregonbirdwatch.org] On Behalf Of Jack Holley
  Sent: Monday, July 21, 2008 10:17 AM
  To: obol at oregonbirdwatch.org
  Subject: [obol] Brood Parasitism

   

         Yesterday as My wife and I were walking our dog in a park in SE Portland, I spotted two young birds not able to fly jet hopping around on the ground. The first was a young crow, and the second was a young Green Heron. There were no marshy areas close to the park. Crows were  flying from one to the other birds. I was wondering if anyone has heard if Green Herons lay their eggs in other birds nest?
       

   



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