Date: 7/3/17 6:12 pm
From: Sebastian <sebastianpatti...> [ILbirds] <ILbirds-noreply...>
Subject: IBET Ring-billed Gull Nesting Colony - Murder Mystery Whodunnit
Good afternoon and Happy Fourth (almost!)

I work at the courthouse that is on the corner of Harrison and Clinton on the near-southwest side of the Chicago loop.

For the past several years, there's been a RBGU nesting colony on the roof on an adjacent commercial building that is

bounded by Harrison on the north, Polk to the south, and Jefferson and Desplaines on the east and west, respectively.

The colony has been expanding over the last 5 years that I've been here, and at present during the morning hours I'd guesstimate

that there are about 150 individuals on the top of the building; a very rough count of nesting mounds in the range of 25-30

nests. Right now there are two sizes of birds of the year: very large juvies (almost adult-sized) and young chicks. The chicks are

not even the size of a small pigeon, and are clearly incapable of anything close to sustained flight. The older juveniles are just

starting to practice short flights.

Here's the mystery: this afternoon on my walk around the building I discovered 15 of the chicks on the public sidewalk on the

east (Jefferson St.) side of the structure. So, whodunit?? I have never seen a human on the roof of the building. So, I guess the

question is whether the adults are killing off neighbor's chicks, or whether it's the older (young) birds that are doing the deed.

(Given the size of the chicks, and their inability to fly, this is not a mass suicide event). I don't have access to the BNA species account,

but I'll get that access in a couple days. In the meantime I'll keep a closer eye on what's going on, and invite any comments from the list-serve!

Sebastian T. Patti
(Lincoln Park)
Chicago, ILLINOIS 60614-3354
PHONE: 312/325-9555 (o)
CELL: 773/304-7488
FAX: 312/325-9017(o)

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