G'day,
In answer to Dean Portelli's question:-
I was particularly aware of the bill size and shape difference of the
Pacific v's the Kelp, so when I saw the bill with the Pacific Gull
characteristics, then I quickly checked for the upper red spot to
confirm, and that was unmistakibly evident.
Neither the upper nor lower red spots however filled to the edges of the
bill tip.
The brown streaks on the nape looked the same as the illustration in the
Morecombe field guide for a Lesser Black-backed gull, except that they
did not extend up over the head.
I am sure that the tail had no black bar, it was all white - observed in
flight as well as perched.
When I indicated "white tips to primaries", they were different on the
folded wings of the resting bird to what you see in a kelp gull. They
formed only 3 spots on the side view, possibly corresponding only to
white tips except for the last 2-3 primaries.
Regards
-----Original Message-----
From:
On Behalf Of Dean
Portelli
Sent: Thursday, 8 May 2003 1:50
To:
Subject: RE: strange gull at Boat Harbour, Kurnell
Hi All (especially people with a good knowledge of gulls)
When Bruce mentioned streaks on the nape the first thing that popped
into my
head was that these were retained feathers from a previous plumage (i.e.
the
bird has moulted into definitive plumage with its last moult). I have
seen
late-stage immature Pacifics with traces of dirty brown on various parts
of
the head and breast area, sometimes only a few feathers. However, this
is
not absolutely the case, it may be an abberant plumage condition (I
recall
an otherwise adult plumage Sooty Tern at Lord Howe with many small
blackish
streaks all over the white parts of it's plumage, it didn't appear to be
due
to soil/dirt or other material on the feathers but rather part of the
plumage).
I would not jump yet to the conclusion of hybrid, seems premature. Does
anyone know if there are any established records of hybridisation
between
these two species?
Bruce: You say the bill was massive - with good views it is usually easy
to
separate Pacific from Kelp Gull purely on the relative shape/size of the
bill. Any further comment?
With respect to the white primary tips - does anyone know if freshly
moulted
primaries may have white tips in Pacific Gulls which are quickly worn
off?
(Although it does seem late for the bird to be moulting - not that I
know
much of moult timing and sequence in this species - god I wish I was
rich
and had all HANZAB volumes at home!).
The other troubling aspect is the tail being all white. It has been
suggested that old Pacifics can lack the subterminal band, but where has
this suggestion come from? So many remarks from earlier literature
(speaking
generally) are based on 'gut feeling' and sometimes they are on the
mark,
while others are way off, and some of them are carried through the
generations and become standard knowledge (yet may be flawed!). Has
someone
simply speculated that the Pacifics lacking the tail band were old
individuals or was their age known accurately? Could it be that
occasional
individuals lack this feature and it is not related to age (as the
streaks
on the nape may indicate the bird is not aged)? So many questions!!!!!!
I welcome comments from people more "in the know" with moulting in gulls
(which I am aware is a complex topic having a friend that has worked
specifically on moulting strategies and plumages in some North American
gulls).
Cheers, Dean
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