further comments on ? Kelp Gull

S. Harvey Mudd, MD (shm@codon.nih.gov)
Tue, 23 Feb 1999 11:07:11 -0500


Bill Mauck kindly sent me his further observations on the mantle color of
the St Mary's ? Kelp Gull.  With Bill's permission, his message is copied below:

On Feb. 20 my wife Cathy and I went down to St. Mary's so she could see the
Kelp Gull.  As it happened, there were 4 GBBGs on the pier with the Kelp.
One of the 4 had a much, much lighter mantle (sub-adult?) while two of the 4
had significantly lighter mantles apparent in any light.  The fourth bird's
mantle was very nearly the same degree of blackness as the Kelp's.  While
all these birds had dry feathers, it does appear the Kelp's mantle is
"shinier" than the GBBGs'. I believe the Kelp's white parts are slightly
whiter than the GBBGs which increases the contrast and thus makes the Kelp's
mantle appear blacker.  Or, as some have said, "crisper."

It does appear that any comparison of the color of the mantle of the ? Kelp
Gull to those of GBBGs will be affected by the particular GBBG to which the
comparison is made.

A book I meant to mention in my posting yesterday that contains a useful
color photo of the underwings of a flying Kelp Gull is "Complete Book of
South African Birds", P.J.Ginn et al, Struik, Cape Town, 1991.  The
underwing of the soaring bird on p. 272 appears to me just like that of the
St Mary's bird which we saw very well as it soared  repeatedly in the wind
last Sunday, Feb 21.  Judging by the black-and-white drawings of the
underwings of Kelp, Herring, and Kelp x Herring F1 hybrids provided by Donna
Dittman on the web (http://losbird.org/kelp.htm) the underwing of the St
Mary's bird to me fit best with that of Kelp Gull.  Nevertheless,  it would
be very useful to the Records Committee to have a copy of any photo that
shows this underwing pattern well.  If anyone has such a photo, please do
make sure an original (to be copied if necessary) or a copy to keep gets to
Phil Davis.  Thanks in advance.

Harvey Mudd 


____________________________________

S. Harvey Mudd
NIMH/DIRP/LMB
Building 36, Room 1B-08
36 CONVENT DR MSC 4034
BETHESDA MD 20892-4034
tel: 301-496-0681;  fax 301-402-0245
email: shm@codon.nih.gov