[mou] Duluth gulls

[Peder Svingen]

At 9:30 AM this morning (12 January), I found an extraordinary number  
of gulls on the ice in the Duluth harbor and watched them for about an  
hour and a half, before they were flushed by a ship departing its  
berth in the Port Terminal. Most of the flock (but not the dark- 
mantled gull mentioned below) subsequently returned, and hundreds of  
gulls were still present until about 3:00 PM. The flock was visible  
from the pedestrian walkway west of the Aerial Lift Bridge in Canal  
Park, and along Minnesota Avenue between 8th and 9th Streets on Park  
Point; gulls could also be seen from Harbor Drive along the southeast  
side of the Duluth Entertainment and Convention Center (DECC), but the  
lighting was poor from that perspective.

Herring Gull -- 1,540 (carefully counted by groups of 10)
Thayer's Gull -- one first cycle and one or two adults
Iceland Gull -- inexplicably absent (3 were at the Superior landfill  
in Dec)
Glaucous Gull -- 18 (11 first-cycle, one second-cycle, 2 third-cycle,  
4 adults)
Great Black-backed Gull -- second-cycle bird found by Kim Eckert in  
the early afternoon

The highlight was an adult dark-mantled gull with rasberry pink legs  
and feet, grayish-brown streaking on its head and neck, dark slate  
gray mantle, white scapular crescent, and broad white tertial  
crescent. Its size was similar to a large Herring Gull (HERG), i.e.,  
larger than an average sized HERG but not as big as the largest HERG.  
This bird was first found by Jim Lind late in the afternoon on the  
10th, and it was watched by Jim, Mike Hendrickson, and myself between  
4:00 and 4:30 PM that day. Digiscoped images taken by Jim Lind on the  
10th, including two remarkable in flight images taken late in the day  
with a handheld digital camera and a Leica Televid 77mm spotting scope  
under overcast skies, and another set of images taken today, are  
posted at http://www.flickr.com/photos/cochon/

Although we were unable to see its wing tips well enough in flight on  
the 10th to make a definitive identification, this bird shows some  
characteristics of Slaty-backed Gull. [Note that an adult Slaty-backed  
Gull was photographed by Karl Bardon at the Superior, Wisconsin,  
landfill on 21 December 2007 -- I have not seen Karl's images.] Great  
Black-backed Gull is apparently ruled out by overall size, bill size  
and shape, and leg color. Western Gull has a larger, bright yellow  
bill, and normally appears white-headed by this time of year. Kelp  
Gull and Yellow-footed Gull have yellowish legs, and also look more  
white-headed in basic plumage. Hybrid gulls also must be considered.

Today's observations were under much better light conditions, looking  
southwest between 9:45 and 10:45 AM under overcast skies, but  
unfortunately, the bird was not seen in flight or extending its wings,  
and the distance was approximately 350 yards. Also posted at the same  
web page mentioned earlier, are images of an adult Slaty-backed from  
the Superior, Wisconsin landfill in November 2006.
--
Peder H. Svingen
Duluth, MN