Date: 6/25/17 2:38 pm
From: Carol Joan Patterson <0000003a0ccbe138-dmarc-request...>
Subject: Re: the end of the cowbird string - maybe
OOPS!!  Now I'm adding my little bit (can't resist):  One human activity that can encourage cowbirds is building more trails or roads that allow cowbirds access to areas they would otherwise not frequent - such as forests, where many bird species, having not normally been exposed to cowbird predation, are acceptors.


From: Kimberly G. Smith <kgsmith...>
To: <ARBIRD-L...>
Sent: Wednesday, June 21, 2017 9:56 PM
Subject: the end of the cowbird string - maybe

<!--#yiv5957584828 _filtered #yiv5957584828 {font-family:Wingdings;panose-1:5 0 0 0 0 0 0 0 0 0;} _filtered #yiv5957584828 {font-family:"Cambria Math";panose-1:2 4 5 3 5 4 6 3 2 4;} _filtered #yiv5957584828 {font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;}#yiv5957584828 #yiv5957584828 p.yiv5957584828MsoNormal, #yiv5957584828 li.yiv5957584828MsoNormal, #yiv5957584828 div.yiv5957584828MsoNormal {margin:0in;margin-bottom:.0001pt;font-size:12.0pt;font-family:"Times New Roman", serif;}#yiv5957584828 a:link, #yiv5957584828 span.yiv5957584828MsoHyperlink {color:blue;text-decoration:underline;}#yiv5957584828 a:visited, #yiv5957584828 span.yiv5957584828MsoHyperlinkFollowed {color:purple;text-decoration:underline;}#yiv5957584828 p {margin-right:0in;margin-left:0in;font-size:12.0pt;font-family:"Times New Roman", serif;}#yiv5957584828 span.yiv5957584828EmailStyle18 {font-family:"Calibri", sans-serif;color:#1F497D;}#yiv5957584828 .yiv5957584828MsoChpDefault {font-size:10.0pt;} _filtered #yiv5957584828 {margin:1.0in 1.0in 1.0in 1.0in;}#yiv5957584828 div.yiv5957584828WordSection1 {}-->I am  attempting to stop this string, but by offering more information, I may allow it to continue…J   Species are either acceptors or rejecters…  this has been known for many years due to the pioneering work of Herbert Friedmann, who published “Host relations of the parasitic cowbirds” in 1963… https://archive.org/details/hostrelationsofp00frie   Of course, his publication predates the release and expansion of House Finches in the eastern US but they appear to be acceptors based on his information…   Acceptors do not recognize cowbird eggs as different from their own… rejecters do and either eject the cowbird eggs, abandon the nest, or build a new nest on top of the nest with cowbird eggs (e.g. Yellow Warblers)   Re habitat change:  Cowbirds have to have somewhere to feed…  their preferred feeding areas are associated with livestock, preferably horses but cattle feedlots will do…  for example, there is almost no cowbird parasitism in the forests of the Ozarks… every study we have done on nesting success has had no effect by cowbirds…  but apparently they are finding feeding areas in urban environments…   The best study of this is by Jared Verner who documented the colonization of the Sierra Nevadas by cowbirds as the horse tourism trade expanded into that area… I can supply references if you are interested   So habitat change per se is not the issue, it is habitat changes that allow cowbirds to find feeding areas…        Cheers, Kim   ******************************** Kimberly G. Smith Distinguished Professor of Biological Sciences Department of Biological Sciences University of Arkansas Fayetteville, AR 72701 Phone:  479-575-6359  fax: 479-575-4010 Email: <kgsmith...> ********************************


 
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