Origins of Black-tailed Gulls in NA

rick (rblom@blazie.com)
Wed, 10 Feb 1999 07:35:47 -0500 

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>Date: Wed, 3 Feb 1999 19:10:27 -0500
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>From: wilsoa02@endeavor.med.nyu.edu (Angus Wilson)
>To: NYSBIRDS-L@cornell.edu
>Subject: Origins of Black-tailed Gulls in NA
>Mime-Version: 1.0
>
>Believe it or not that are even more North American records of Black-tailed
>Gull than listed by Bob Lewis. There are records from Canada (several), the
>USA (several), Mexico and even Belize.
>
>Initial concerns about the origins of Black-tailed Gulls in North America
>centered on the fact that several of the initial records came from near
>major shipping ports. San Diego and Norfolk Virginia are most notable in
>being major US Navy bases with heavy traffic to and from Asia. Even the
>bird in Rhode Island didn't seem immune to concerns about unatural
>transportation. I recall serious discussions as to whether a gull would
>still follow a ship (and its galley scraps) as it passed through the locks
>of the Panama Canal!
>
>I think the most exciting Black-tailed Gull record to date is of a bird
>seen near Winnipeg in Manitoba, Canada. Clearly this is a very long way for
>the nearest naval base (although I don't know about naval airbases!). If I
>recall correctly, the record was from June. This may provide evidence that
>birds entering North America (perhaps via the Aleutian Chain) filter down
>across the Continent, ending up on the Atlantic coast. Other birds may
>simply move down the west coast reaching California and Baja Mexico.
>Long-billed Murrelets, another asiatic species, may follow a similar route.
>It is also interesting to note that Black-tailed Gull has not yet been
>recorded in Europe. This might argue against ship assistance theories.
>
>One last point. There are at least two (or possibly three) Black-tailed
>Gulls on the eastern seaboard at the moment. On Sunday the 31st Jan, the
>first day the NY bird was seen, another adult was still present at the
>Chesapeake Bay Bridge-Tunnel in Virginia. On one occasion (in early Jan?),
>two birds were reported from the CBBT. We do not know whether this second
>bird became the New York bird. It seems very likely however, that the New
>York bird is the same individual that has been seen at Cape May and then at
>the Manasquan Inlet earlier last month.
>
>Angus Wilson
>
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>tel: (212) 263-0206
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>E-mail: wilsoa02@popmail.med.nyu.edu
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>

"A great many people now reading and writing would be better employed
keeping rabbits." Edith Sitwell


Rick Blom
rblom@blazie.com
4318 Cowan Place
Belcamp, Maryland 21017
(410)575-6086