Subject: [Tweeters] Bob is a Glaucous Gull
Date: Jan 12 15:41:54 2009
From: miechel - mtabak at shaw.ca


As someone who has spent considerable time studying gull identification I can tell you with certainty that Bob is a Glaucous Gull, and not an Iceland Gull. From what I recall of previous discussions on this topic, that also is the general consensus of experienced birders on this chat group, with only a very few arguing that Bob is an Iceland Gull, and others who simply do not know. I've looked at the photos showing Bob in direct comparison with enough Glaucous-winged Gulls that the general large size and bulk is obvious. As well numerous observers have given verbal discriptions indicating that Bob is slightly smaller than an average sized Glaucous-winged Gull. The average sized Glaucous-winged Gull is a large bulky gull. While a huge male Iceland Gull might be larger than the smallest Glaucous-winged Gull, it will not be nearly the size of of an average Glaucous-winged Gull. So Bob cannot be an Iceland Gull because it is simply too big and bulky. I have personally seen a few Glaucous Gulls on the West Coast that were a bit smaller than an average sized Glaucous-winged Gull. These smaller Glaucous Gulls were about the size of Bob, so I can say with certainty that Glaucous Gulls do occur in our area of this size. I also have in the field identification experience with Iceland Gulls, so this is why I am confident that Bob is not one. I think it is difficult to get a good sense of Iceland Gull size from photos alone. And there are very few photos in existence showing Glaucous-winged Gulls and white-winged Iceland Gulls together in the same photo. That is why I posted an url to my own photos of these two species together. On page 220 of the large Sibley fieldguide he says of Glaucous Gulls "small adults distinguished from Iceland Gull by slightly bulkier proportions, always clear yellow iris, and unmarked white wingtips", also" some have red orbital ring" Bob appears to have all of these characteristics. Now factor in the extreme rarity of a white-winged Iceland Gull on the west coast, and the fact that these Iceland Gulls do not overlap in size with an average sized Glaucous-winged Gull, and you have clear cut case for Bob being a Glaucous Gull. And since male gulls are usually larger than females, and this is a small Glaucous Gull, then it is likely a female and would be better named Roberta. I realize most folks are in the Glaucous Gull camp here, and some others will likely never be convinced, but if you want some objective expert opinion why not send a post and some photos to the Frontiers of Identification website? I'm pretty sure that folks who are actually experienced with Iceland Gulls will quickly clarify that Bob is not an Iceland Gull, and looks like a small but normal Glaucous Gull. Mike Tabak Vancouver BC