þÿ<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta name=Title content="GASTON, A"> <meta name=Keywords content=""> <meta http-equiv=Content-Type content="text/html; charset=unicode"> <meta name=ProgId content=Word.Document> <meta name=Generator content="Microsoft Word 11"> <meta name=Originator content="Microsoft Word 11"> <link rel=File-List href="25_2_119-126_files/filelist.xml"> <title>GASTON, A</title> <!--[if gte mso 9]><xml> <o:DocumentProperties> <o:Author>Gaston</o:Author> <o:Template>Normal</o:Template> <o:LastAuthor>Benjamin Saenz</o:LastAuthor> <o:Revision>2</o:Revision> <o:Created>2008-05-12T18:01:00Z</o:Created> <o:LastSaved>2008-05-12T18:01:00Z</o:LastSaved> <o:Pages>1</o:Pages> <o:Words>207</o:Words> <o:Characters>1182</o:Characters> <o:Company>Environment Canada</o:Company> <o:Lines>9</o:Lines> <o:Paragraphs>2</o:Paragraphs> <o:CharactersWithSpaces>1451</o:CharactersWithSpaces> <o:Version>11.1025</o:Version> </o:DocumentProperties> <o:OfficeDocumentSettings> <o:PixelsPerInch>96</o:PixelsPerInch> <o:TargetScreenSize>800x600</o:TargetScreenSize> </o:OfficeDocumentSettings> </xml><![endif]--><!--[if gte mso 9]><xml> <w:WordDocument> <w:Compatibility> <w:UseFELayout/> </w:Compatibility> </w:WordDocument> </xml><![endif]--> <style> <!-- /* Font Definitions */ @font-face {font-family:"Times New Roman"; panose-1:0 2 2 6 3 5 4 5 2 3; mso-font-charset:0; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:50331648 0 0 0 1 0;} @font-face {font-family:Arial; panose-1:0 2 11 6 4 2 2 2 2 2; mso-font-charset:0; mso-generic-font-family:auto; mso-font-pitch:variable; mso-font-signature:50331648 0 0 0 1 0;} @font-face {font-family:"MS Mincho"; panose-1:0 0 0 0 0 0 0 0 0 0; mso-font-alt:"ÿ-ÿ3 fg"; mso-font-charset:128; mso-generic-font-family:roman; mso-font-format:other; mso-font-pitch:fixed; mso-font-signature:1 134676480 16 0 131072 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0in; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Arial; mso-ansi-language:EN-CA; mso-fareast-language:JA;} table.MsoNormalTable {mso-style-parent:""; font-size:10.0pt; font-family:"Times New Roman";} @page Section1 {size:8.5in 11.0in; margin:1.0in 1.25in 1.0in 1.25in; mso-header-margin:35.4pt; mso-footer-margin:35.4pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> </style> </head> <body bgcolor=white lang=EN-US style='tab-interval:.5in'> <div class=Section1> <p class=MsoNormal><span style='font-family:"Times New Roman";text-transform: uppercase;mso-ansi-language:EN-US'>Gaston, A.J., Ydenberg, R.C</span><span style='font-family:"Times New Roman";mso-ansi-language:EN-US'>. &amp; SMITH, G.E.J. 2007.</span><span lang=EN-CA style='font-family:"Times New Roman"'> Ashmole s halo and population regulation in seabirds. <i>Marine Ornithology</i></span><span lang=EN-CA style='font-family:"Times New Roman"'> 35: 119-126.<o:p></o:p></span></p> <p class=MsoNormal><span lang=EN-CA style='font-family:"Times New Roman"'><b><![if !supportEmptyParas]>&nbsp;<![endif]><o:p></o:p></b></span></p> <p class=MsoNormal><span lang=EN-CA style='font-family:"Times New Roman"'>Ashmole s Halo is the term given to a zone of food depletion thought to surround the concentrations of predatory birds that exist in large seabird colonies. Philip Ashmole developed the hypothesis during studies of tropical terns. However, the idea has been widely applied outside the tropics and most evidence for the hypothesis has been based on studies of high-latitude seabirds. We model some expectations for measurable variables, including foraging range, food availability and offspring development in relation to colony size for four seabird types (based on characteristics of the genera <i>Uria</i></span><span lang=EN-CA style='font-family:"Times New Roman"'>, <i>Fratercula</i></span><span lang=EN-CA style='font-family:"Times New Roman"'>, <i>Puffinus</i></span><span lang=EN-CA style='font-family:"Times New Roman"'> and <i>Pterodroma</i></span><span lang=EN-CA style='font-family:"Times New Roman"'>) and test the model predictions against currently available data. We conclude that, although there is evidence for the existence of a zone of food depletion around seabird colonies, our model suggests that it is unlikely to be detectable for small colonies and especially for colonies of far-ranging species such as petrels and shearwaters. The hypothesis can be tested more effectively by measuring how food, feeding rates and feeding behaviour vary with distance from a colony than by comparing foraging at colonies of different sizes.<o:p></o:p></span></p> <p class=MsoNormal><span lang=EN-CA style='font-family:"Times New Roman"'><![if !supportEmptyParas]>&nbsp;<![endif]><o:p></o:p></span></p> <p class=MsoNormal><span lang=EN-CA style='font-family:"Times New Roman"'><b>Keywords</b></span><span lang=EN-CA style='font-family:"Times New Roman"'>: Seabirds, foraging range, food, energetics, central place foraging,<i> Uria</i></span><span lang=EN-CA style='font-family:"Times New Roman"'>, <i>Fratercula</i></span><span lang=EN-CA style='font-family:"Times New Roman"'>, <i>Puffinus,</i></span><span lang=EN-CA style='font-family:"Times New Roman"'> <i>Pterodroma<o:p></o:p></i></span></p> <p class=MsoNormal><span lang=EN-CA><![if !supportEmptyParas]>&nbsp;<![endif]><o:p></o:p></span></p> </div> </body> </html>