Taxonomic Status of Common Gull and Mew Gull
Phil Davis (pdavis@ix.netcom.com)
Tue, 06 Jan 1998 04:35:12 -0500
Several days ago. I posted an answer to a question by Norm Saunders about
the status of the split between Mew and Common Gull. A corrected answer is
provided in the message thread, below.
Norm Saunders asked:
>Phil,
>
>I was reading about Common Gull last evening in Grant. Do you know
>offhand which of the races mentioned in that book will make up the
>Mew Gull split?
At 04:05 AM 01/02/1998 -0500, Phil Davis wrote:
>> The Brits have split the Mew Gull into Mew and Common Gull. It is
>> expected that the AOU will soon follow suit.
>>
>> Technically, as of today, you would tick it off as a Mew Gull ...
>> but note the difference so when the AOU splits it, you can "claim"
>> it as a Common Gull.
This information was not correct ... the BOU has not split these species.
Harvey Mudd, the Chair of the MD/DCRC Records Committee, has provided the
actual status in a message, below, which I forward with his permission.
Thanks for clarifying this, Harvey!
>To: PDavis@ix.netcom.com
>From: "S. Harvey Mudd, MD" <shm@codon.nih.gov>
>Subject: taxonomic status of Common Gull and Mew Gull
>
>Dear Phil,
>
>The discovery of the Common Gull at Conowingo by Bruce Peterjohn and Mary
>Gustafson on New Year's Day, 1998, has prompted me over the past few days to
>try to clarify in my mind the current taxonomic status of Larus canus and
>the four forms regarded currently by most authorities as subspecies or
>races (i.e. L.c. canus, heinei, kamtschatschensis, and brachyrhynchus). As
>far as either Bruce Peterjohn or I know, Larus canus has not formally been
>split by either AOU or BOU (the British Ornithologic Union). However,
>Charles Sibley in his computerized "Birds of the World" (version 2.0, 1996)
>does split Common Gull, Larus canus, from Mew Gull, Larus brachyrhynchus.
>He says there is a cline from western Europe through Siberia in which L.c.
>canus grades gradually to L.c. kamtschatschensis. He retains these forms
>(and presumably the geographically intermediate L.c. heinei) as a single
>species. There is then an abrupt change to the form that Sibley now splits
>as Mew Gull, Larus brachyrhynchus. He cites a study by Zink et al. (Condor
>97:639-649, 1995) that is said to report differences between the
>mitochondrial DNA's of kamtschatsensis and brachyrhynchus sufficient to
>support splitting them into distinct species.
>
>The observations of all birders to whom I have talked about the gull now at
>Conowingo, and my own observations, all seem to indicate this individual is
>clearly a L. c. canus in first winter plumage, the plumage in which it is
>probably easiest to distinguish this form from brachyrhynchus. If this
>identification withstands critical examination of the written and
>photographic documentation, and if the AOU follows Sibley in splitting these
>forms, those observers who need it should be able to add Common Gull to
>their lists for Harford County, Maryland, North America, and perhaps others,
>as appropriate.
>
>S. Harvey Mudd
Phil
PS - I am leaving town for a week, so I won't be available to respond to
anything more on this thread at this time.
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Phil Davis
home: PDavis@ix.netcom.com Davidsonville, Maryland, USA
work: PDavis@OAO.com Greenbelt, Maryland, USA
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