This is from Birdchat. There is a discussion about Ross' Gull there,
stemming from an eastern sighting in Canada (Fort Chambly). Since Ross'
Gulls have been on our mind, thought it might be interesting...

____________________________
Mike Smith
Univ. of Washington, Seattle
whimbrel at u.washington.edu

---------- Forwarded message ----------
Date: Wed, 7 Dec 1994 19:34:20 -0500
From: Byron Butler (GD 1995) <bbutler at MINERVA.CIS.YALE.EDU>
To: Multiple recipients of list BIRDCHAT <BIRDCHAT at ARIZVM1.ccit.arizona.edu>
Subject: Re: ross' gull

On Wed, 7 Dec 1994, David J. Lauten wrote:

> i wonder if the eye placement on the head of the ross' gull reflects their
> feeding habits. several years ago i unsuccessfully chased a ross' gull in

I had planned to discuss this in my original post, then forgot to do so.
Yes, I am hypothesizing that there is a suite of adaptations for foraging
in the Ross's Gull that include the forward directed eyes, short neck,
and short bill. Unfortunately, the Yale Peabody Museum osteology
collection does not have a Ross's Gull skeleton so I can not study the eye
orbit. Nor is their much literature on the life history of this gull, so
far I've not had time to dig deep into the literature to see what is
known of its foraging habits. I predict, however, on the basis of its
morphology, limited range (its main area is the Kolyma delta in e.
Siberia), and its rareness elsewhere, that it is a specialist of some sort,
perhaps a foraging specialist. I would be interested in any information
others are able to dig up on the life history of this species.

> this!!!!). anyhow, back to the original question: how is the bird in
> montreal feeding? is it feeding on mudflats, or close to the surface of the
> water where binocular vision would be an enhancement? does anyone know how
> these birds routinely feed?
>
I never saw the bird feed. I found this very interesting because I
arrived at the site shortly after first light, the bird was not actively
foraging at the time. It never did forage the entire time I was there
even though it landed on rocks in the river. The gull appeared to me to be
satiated and resting. I asked myself the question, if it wasn't hungry
at first light, when did it last eat? Maggie and I had driven all
through the night, it was still dark at 7:00am and we saw the bird by
7:45am. We had been looking for it since 7:15am and it must have been
sitting on the pier where it was finally spotted the whole time because
we never saw it among the active birds -- as we were to learn,
Ross's Gull is easy to pick out of hundreds of Bonaparte's once you know
what to look for. Because Maggie and I had driven all night our eyes
were dark adapted by the time we got near Fort Chambly. I recall telling
Maggie at 6:45am that it was light enough for dark adapted birds to be
active. Perhaps this gull fed before 7:15am or perhaps it is a nocturnal
feeder. Another possiblility is that it doesn't need to eat everyday.
Graham Martin's "Birds by Night" does not mention Ross's Gull. Again, any
information on the life history of this gull would be welcome.

Ross's Gull was discovered (for science) on 23 June 1823 on the Melville
Peninsula near Igloolik by James Clark Ross (1800-1862) when Ross and
another person on the expedition shot two specimens. Nomenclatural
priority goes to William MacGillivray due to a paper he presented to the
Wernerian Society in February, 1824 and published that year.
MacGillivray's common name for it was Ross's Rosy Gull, the binomen he
assigned was Larus roseus. The genus name has since been changed and it
is now known as Rhodostethia rosea (MacGillivray).

Byron K. Butler, Guilford, CT