Identification of Kelp Gull in Maryland
Rob Hilton (robert@csa.com)
Fri, 19 Feb 1999 13:39:30 -0500
Hi everyone,
I unfortunately don't have the time to post very much about the Sandgates
Kelp Gull. I agree with everything Ottavio says in his message (below)
which he has asked me to post on MDOsprey.
The Dwight reference is the pioneer account of molt and plumage for all the
gulls of the world. I don't know the full citation offhand.
Rob Hilton
robert@csa.com
Bethesda, MD, working hours only
++++++++++++++++++++++++++++++
Hi,
I've been reading with interest the posts about the Kelp Gull. At this
point I feel pretty confident in saying that the ID issue is resolved and
that the bird is definitely a Kelp Gull. I've had the chance to talk to
more people, look at my photos, and see more references and every character
on this bird is entirely consistent with Kelp Gull and rules out all other
species and I think any hybrid combination. Alvaro Jaramillo, who has lots
of field experience with Kelp Gull and is preparing an ID article on this
species for "Birding", has seen one of the photos and feels that the bird
is "dead-on" for Kelp Gull.
Some hybrid combinations have been proposed, but I feel all can be ruled
out:
Kelp X Herring: Greg Miller does a good job in pointing out the differences
between an F1 (first generation) Kelp X Herring hybrid and the Sandgates
bird (see the online article at the LOS website). I think an F2 hybrid
between Kelp X Herring and a Kelp Gull should show at least some
intermediate characters, which this bird doesn't show. As Rob Hilton
pointed out to me, an F3 hybrid (between a Kelp and an F2 hybrid) is
chronologically impossible, with Kelp Gulls having arrived in Louisiana in
1989, and the Sandgates Gull being 5 years old at least (it was an adult
last year as well).
Great Black-backed Gull X Herring: Again, as per Greg Miller's post, size,
mantle color, leg color, etc. easily rule this out.
Lesser Black-back X Great Black-back has been mentioned. I don't know of
any records of this combination, but I think leg color and very small
amount of white in the wings would rule it out.
I've had a chance to look at the Kelp Gull account in Dwight (1925) and
there were some interesting tidbits. Dwight mentions the small white
tongues on P5 and P6 [seventh and sixth primaries in from the tip--Rob]
which the Sandgates bird shows (and which I've seen on
a couple of photographs of Kelp Gull). Furthermore, as Dave Czaplak
suggested, Dwight confirms that birds in fresh plumage (which the Sandgates
bird is in) show a gray bloom to the mantle making them look slightly paler
that the worn birds, which become blacker. I think some were concerned
about the paleness of the mantle, but taking in to account the above and the
fact that most observers who've seen the Sandgates bird next to GBB agree
that it is as dark or darker than GBB I don't think there is much need for
concern anymore.
So, to recap all the features. Structure: excellent for Kelp Gull. Size:
fine for Kelp Gull. Leg color: perfect for Kelp Gull. Other soft part
colors (eye, orbital ring, bill): perfect for Kelp Gull. Mantle shade:
perfect for Kelp Gull. Wing pattern: perfect match for Kelp Gull. Head
streaking: fine for Kelp Gull. Al Jaramillo thought it was fine for basic
adult Kelp, and Dwight mentions that basic adults have some very faint head
streaking. The bird is in basic plumage and therefore on a northern
hemisphere molt cycle, unlike its congeners in South America. According to
Al Jaramillo however this is no cause for concern and only suggests that
this bird has been in the northern hemisphere for a while.
Still, I think it is an excellent idea to keep photographing and documenting
this gull, and it would be very useful if someone could obtain tape
recordings.
Ottavio Janni
ottavioj@iadb.org