Date: Fri, 20 Apr 2001 10:53:48 -0400 Reply-To: Maryland Birds & Birding Sender: Maryland Birds & Birding From: Susan Heath Subject: Re: Yellow-throated Warbler subspecies in MD and theirhabitats MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit My ecology book has a reference to the longer bill size in Yellow-throated Warblers on the Delmarva Penn as an example of character displacement. When two species are allopatric (living in separate geographical ranges) they have nearly identical physical characteristics. When they are sympatric (living in the same geographical range) such as Pine and Yellow-throated Warblers on the Delmarva Penn, the physical or morphological characteristics diverge in one or both species. The Yellow-throated Warblers on the Delmarva Penn have developed larger bills so they can feed on larger insects than Pine Warblers. The list of references for that chapter doesn't say which reference is for that specific example, but I will find out and post it. Sue Paul O'Brien wrote: > As an aside, I remember reading that the longer bill of the yellow-lored > dominica race of Yellow-throated Warbler evolved very rapidly, over the > course of the 20th century! Does anybody have that reference? > > Paul O'Brien > Rockville, Mont. Co., MD > pobrien776@aol.com > > ======================================================================= > To leave the MDOsprey list, send e-mail to listserv@home.ease.lsoft.com > with the following message in line 1: signoff mdosprey > ======================================================================= -- Susan Heath Fairfax County Centreville, VA sheath@erols.com ======================================================================= To leave the MDOsprey list, send e-mail to listserv@home.ease.lsoft.com with the following message in line 1: signoff mdosprey ======================================================================= =========================================================================