|First cycle Thayer's Gull. NPM, IL. 26 FEB 2012.|
No "mass exodus" was observed at any one point throughout the day, but rather, 2-3 small groups of 75-100 gulls were noted flying westward early in the morning (very likely to the Zion landfill). Returning numbers from the west consisted of small, loose, groups throughout most of the day. There were two instances when ALL of the gulls got up and were reshuffled, once because of a low-flying helicopter and once because of a Snowy Owl that came in directly over the harbor from south to north. This Snowy was markedly whiter than last week's bird.
Hourly counts verified a constant flow of gulls coming and going, which was expected. For instance, between the hours of 7- 11 a.m., at least 4 adult Lesser Black-backeds were noted, but not one was to be seen again for the entire day shortly after 11:00 a.m.
The Herrings began their evening cacophony of yelps, mews and caws around 4:45 p.m., and at 5:10 p.m., approximately 3/4 of them took wing in unison and flew out quite a distance over the lake. Why some Herrings stayed in the harbor is puzzling, but the majority of Ring-billeds (~ 150) stayed in the harbor as well. With that said, I'd point out that birds noted coming into the harbor during the early morning hours were ones that very likely roosted on Lake Michigan.
|An intermediate Thayer'/Kumlien's type, tending towards Kumlien's. NPM, IL. 26 FEB 2012.|
|A well-marked adult Thayer's.|
11 Thayer's Gulls (8 distinct adults, 1 second cycle, 2 first cycle).
4 Kumliens' Iceland Gulls (4 adults. One of these adults showed all white wingtips but with upperparts that matched Herring - see photos).
2 Glaucous Gulls (1 adult, 1 first cycle).
7 Lesser Black-backed Gulls (4 adults, 1 third cycle, 2 first cycles).
1 Great Black-backed Gull (1st/2nd cycle).
|Adult Kumlien's Gull with stage zero wingtip pattern. Upperparts matched surrounding Herrings.|
|Tending towards Kumlien's (same bird as above).|
|Thayer's/Kumlien's in back with dark eye. American Herring in front.|
|First cycle Ring-billed Gull.|
|First cycle Thayer's (a bit on the pale end).|