Funny, but I was going to ask about this shrike yesterday to see if anyone had taken a long hard look at it. I saw another photo and I just can't make it into a Northern Shrike.
I have put some photos of a specimen from the Cornell Museum of Vertebrates that might be of interest at http://picasaweb.google.com/KevinJ.McGowan/SpecimenExamples It is a hatch year female taken in Mecox, Suffolk Co. on 26 November 1946. It shows neat light barring across the chest, a gray unbarred back, and a pale patch at the base of the bill. Several individuals in the collection looked similar. The Jones Beach individual looks very similar to my eyes, except that it doesn't have the retained juvenal wing coverts, but that molt can be variable among individuals. Shai's real Northern Shrike photo shows very substantial contrast in shape, bill shape, mask size, coloring, and markings. I was not able to find a single specimen of Northern Shrike in the Cornell collection that even remotely looked odd or like the Jones Beach bird. Not to say that the collection encompasses the entire variation, but they all looked pretty much alike. Interesting bird. Here's hoping it really is a young Loggerhead; the population could use it! Keivn Kevin J. McGowan, Ph.D. Instructor Home Study Course in Bird Biology Cornell Lab of Ornithology 159 Sapsucker Woods Road Ithaca, NY 14850 hst...@cornell.edu 607-254-2452 From: bounce-7483490-3714...@list.cornell.edu [mailto:bounce-7483490-3714...@list.cornell.edu] On Behalf Of Hugh McGuinness Sent: Wednesday, December 01, 2010 9:43 AM To: Shaibal Mitra Cc: NYSBIRDS (NYSBIRDS-L@cornell.edu) Subject: Re: [nysbirds-l] Identity of Jones Beach Shrike Just to add some other images, here are some photos of Loggerhead Shrike photo showing vermiculations http://www.beachhunter.net/blog/2008/04/wherefore-art-thou-loggerhead.html http://sdakotabirds.com/species/loggerhead_shrike_info.htm And here is Kevin McGowan's pretty excellent review of the two species using specimens. http://www.birds.cornell.edu/crows/loggerhd.htm Hugh On Wed, Dec 1, 2010 at 9:25 AM, Shaibal Mitra <shaibal.mi...@csi.cuny.edu<mailto:shaibal.mi...@csi.cuny.edu>> wrote: I forgot to include links to photos. Here are a few of my own, with a couple of Northern Shrike shots for comparison: http://picasaweb.google.com/tixbirdz/LongIslandMiscellany2010#<http://picasaweb.google.com/tixbirdz/LongIslandMiscellany2010> Here are some from John Gluth: http://www.flickr.com/photos/jgluth_brb/sets/72157625379326695/with/5212944549/ ________________________________________ From: bounce-7483412-3714...@list.cornell.edu<mailto:bounce-7483412-3714...@list.cornell.edu> [bounce-7483412-3714...@list.cornell.edu<mailto:bounce-7483412-3714...@list.cornell.edu>] On Behalf Of Shaibal Mitra [shaibal.mi...@csi.cuny.edu<mailto:shaibal.mi...@csi.cuny.edu>] Sent: Wednesday, December 01, 2010 9:16 AM To: NYSBIRDS (NYSBIRDS-L@cornell.edu<mailto:NYSBIRDS-L@cornell.edu>) Subject: [nysbirds-l] Identity of Jones Beach Shrike A shrike present at Jones Beach West End, Nassau County, LI has been identified by many as a Northern Shrike, but a considerable amount of back-channel discussion has questioned whether it might actually be a Loggerhead. When I finally saw this bird well this past weekend I was already aware of the debates surrounding its identity, so I made an effort to evaluate the various characters that have been proposed in support of each species. As might be suspected multiple features have been proposed to support each view, so the question is how to evaluate the relative reliability of each character. To me, the bird appeared relatively small and quick (vs. the large and lanky impression usually imparted by Northern Shrike), with a relatively large head, rounded crown, and short bill--all consistent with Loggerhead Shrike. Also consistent with Loggerhead Shrike was the relatively dark gray tone to its back. Features more consistent with Northern Shrike include: extensively pale base to lower mandible, heavily hooked upper mandible, the shape of the black mask behind the eye, obvious gray barring on the breast in the absence of any barring on the back. The appearance of this bird's mask in the area of the eye itself and in front of the eye seems equivocal and has been argued in both directions, but I find it easier to find photos of Loggerheads that match its facial appearance than photos of Northerns that do so. Taking these features individually, I think that individual variation could account for many discrepancies either way. For instance, it seems plausible that some Northern Shrikes could have small bills and that some Loggerheads could have heavily hooked bills, etc. To me, the difficult questions are: 1. Could a Northern Shrike could look so small, quick, and large-headed? 2. Could an immature Loggerhead Shrike show a pale-based mandible and ventral barring in the absence of dorsal barring? 3. Is this bird's mask pattern possibly diagnostic, despite the conflicting impressions of local observers? Any constructive answers to these questions would be greatly appreciated! Shai Mitra Bay Shore Think green before you print this email. -- NYSbirds-L List Info: http://www.NortheastBirding.com/NYSbirdsWELCOME http://www.NortheastBirding.com/NYSbirdsRULES ARCHIVES: 1) http://www.mail-archive.com/nysbirds-l@cornell.edu/maillist.html 2) http://birdingonthe.net/mailinglists/NYSB.html 3) http://www.surfbirds.com/birdingmail/Group/NYSBirds-L Please submit your observations to eBird: http://ebird.org/content/ebird/ -- Think green before you print this email. -- NYSbirds-L List Info: http://www.NortheastBirding.com/NYSbirdsWELCOME http://www.NortheastBirding.com/NYSbirdsRULES ARCHIVES: 1) http://www.mail-archive.com/nysbirds-l@cornell.edu/maillist.html 2) http://birdingonthe.net/mailinglists/NYSB.html 3) http://www.surfbirds.com/birdingmail/Group/NYSBirds-L Please submit your observations to eBird: http://ebird.org/content/ebird/ -- -- Hugh McGuinness The Ross School 18 Goodfriend Drive East Hampton, NY 11937 -- NYSbirds-L List Info: http://www.NortheastBirding.com/NYSbirdsWELCOME http://www.NortheastBirding.com/NYSbirdsRULES ARCHIVES: 1) http://www.mail-archive.com/nysbirds-l@cornell.edu/maillist.html 2) http://birdingonthe.net/mailinglists/NYSB.html 3) http://www.surfbirds.com/birdingmail/Group/NYSBirds-L Please submit your observations to eBird: http://ebird.org/content/ebird/ --
