Date: Sat, 14 Dec 2002 12:09:56 -0500 Reply-To: Maryland Birds & Birding Sender: Maryland Birds & Birding From: Walter Ellison Subject: Re: IDing individual Blue Jays MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Hi Tom and other Osprey readers, It should be possible to come up with individual identification of almost any bird with complex patterned plumage as long as one takes into account physical change in plumage through wear and other factors (being wetted for instance) and molt. In jays not only should the white "vee" into the gray breast be useful, but details of the black breast "necklace", the amount of white and blue in the face, and the extent of black in the face should also combine to produce a distinctive pattern in each individual bird. Only using the white "vee" would not be quite as reliable as a combination of patterns including underpart and head pattern. The breast and belly feathers are indeed prone to occasional rearrangement, that is why on rare occasion one sees a Song Sparrow lacking a breast spot. I am unsure the plumage pattern would remain stable across molts however, because each molt has its own history of feather building. Birds eat better or worse and experience different weather in each molt period leading to a subtly unique plumage every time molt takes place. That's why biologists use more "permanent" markers, such as color bands, for long-term population studies. Sorry to go on so long about this, but I did some similar plumage ID work on American Redstarts in New Hampshire awhile ago. Good observation. Good Birding, Walter Ellison MD-DC Atlas Coordinator - MOS 23460 Clarissa Road Chestertown, MD 21620 phone: 410-778-9568 e-mail: rossgull@crosslink.net "A person who is looking for something doesn't travel very fast" - E. B. White (in "Stuart Little") ----- Original Message ----- From: "Tom Beal" To: Sent: Friday, December 13, 2002 9:26 AM Subject: [MDOSPREY] IDing individual Blue Jays > I was watching the Blue Jays gorging themselves on peanuts this > morning when > I notice that the white stripe/streak/wedge that extends up from their belly > into the gray of their breast seems to be distinctive on each > individual. Something like the tail patterns on whales. I am thinking > of using our new digital camera to capture images of the birds > and see something about the local population visiting the feeder, > size, group > structure, etc. > > Does anybody think these patterns will lead to individual > identifications or > do you think the patterns constantly change due to movement, preening, > bathing, etc.? > > Tom Beal > Glenn Dale, MD ======================================================================= To leave the MDOsprey list, send e-mail to listserv@home.ease.lsoft.com with the following message in line 1: signoff mdosprey ======================================================================= =========================================================================