26 January 2012

NPM Thayer's Gull

I found this first cycle Thayer's Gull at North Point Marina on Sunday. NPM is one of Illinois' premier winter gulling sites which sits almost directly on the Illinois/Wisconsin state line along Lake Michigan:

First cycle Thayer's Gull. North Point Marina Illinois. 22 January 2012.

I consider this individual to be on the dark side for Thayer's. Here's this same photo lightened up:

One mark that I like to use in flight - although not popularized in our field guides - are the undertail coverts. Thayer's tends to display more neatly patterened undertail coverts that show horizontal bars:
Same individual as above.

Similar aged Herring's tend to show undertail coverts that are more wavy and "messy". Often times, the buff coloring is thiner (or thicker) in width than the alternating brown rows in Herring.

21 January 2012

A "Chicago" California Gull

Chicago got its biggest snow storm of the season on Friday which tends to really change the gulling dynamics along the lakefront. So, I went to Calumet Park the next morning to conduct a "well-being" check on the gulls. The gulls were really receptive and no more than 5 minutes of chumming brought in this adult California Gull:

Adult California Gull. Calumet Park. Chicago, IL. 21 Jan 2012.
CAGU is now annual in Illinois with the majority of records coming from Lake County. The entire state averages maybe 1-2 birds per year. Coincidentally, this individual was found by Josh Engel on the Chicago CBC on Christmas Day. Almost a month later and 12 miles south, it continues to work the lakefront. The great thing about birding Calumet Park is that the state line is literally a rock's throw to Indiana. Any gull seen in Illinois is always a "to and from" Indiana bird, although not all birds in Indiana always enter Illinois.