iris color of ? Kelp Gull

S. Harvey Mudd, MD (shm@codon.nih.gov)
Mon, 22 Feb 1999 16:45:52 -0500 

Last Tuesday, Feb 22, as I left to go look for the ? Kelp Gull in St Mary's
County, I hurriedly took from the shelf a copy of the photographic edition
of P. Harrison, "A Field Guide to Seabirds of the World", Stephen Greene
Press, 1987.  A quick, enroute reading of the text on Kelp Gull, p. 253,
revealed the statement that the Kelp Gull "differs from .... Lesser
Black-back Gull in dark
iris ...".  Upon gaining an excellent view of the iris color of the actual ?
Kelp Gull it was at first hard to reconcile the above description with the
color of the eye on the bird itself.  The iris has by now been described as
"pale grayish-yellow" (Michael O'Brien), "light" (Phil Davis), "pale,
greenish/grayish/yellowish (not brighter yellow as on most LBB)" (Ottavio
Janni), and "gray-yellow" (Wilbur Hershberger).  The words that come closest
to describing what I perceive might be "pale yellow with a slight grayish
wash or overtone".  A bit of further reading relieved the supposed
discrepancy when I came across the comment in the earlier [i.e
non-photographic] Harrison book, "Seabirds", Houghton Miflin, 1983:  "Two
subspecies; L.d. vetula .... [the subspecies that breeds on the coasts of
southern Africa] has a darker eye".   Among several books with large actual
photographs of Kelp Gulls in areas to which they are native, "Shorebirds of
Australia", J.D.Pringle, Angus & Robertson, 1987, p.500,  contains a
half-page color photo of a sitting Kelp Gull in which, to my eye, the iris
color (as well as that of the orbital ring) is exactly like that of the St.
Mary's bird.  "Birds of the South Western Cape", Joy Frandsen, Sable, 1982,
p.103-104, has two large color photos.  In one the iris appears a bit
darker; in the other, a bit lighter than that of the St Mary's bird.
Finally, the Kelp Gull in the photo in "Field Guide to the Birds of Southern
Africa", Ian Sinclair, C. Struik, 1984, p.139, seems to show a darker iris,
although it is not really well visualized.  Further indication hat there may
well be geographic (as posited in the text by R.C.Murphy quoted on the Bob
Lewis website),  age-dependent, and/or perhaps individual differences, is
provided by the description in "Field Guide to the Birds of Australia", G.
Pizzey, Princeton Univ. Press, 1980, p.140: "eye to brown, yellow-brown and
finally white". 

Harvey  


____________________________________

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