25 October 2011

Adult or Not?

I birded Clinton Lake in Illinois yesterday. I started my birding at the Parnell Bridge at sunrise while waiting to meet up with others for a Yellow Rail walk. The bridge separates the northern most section of the lake (Salt Creek area) from the eastern and southern part of the lake. Historically, this site was a reliable spot for Little Gulls but no longer is (which holds true for most other sites across the Midwest).

Bonaparte's were streaming in over the bridge which presented a good photographing opportunity (even more so when I would use the trees as a blind). Interestingly, if an incoming gull noticed my presence, it would veer slightly off the course that would have brought it directly over me. I realized a scenario that would make for ideal photographing: what if, as crazy as this idea seems, one was to set up a few "scare crows" on each end of the bridge while I myself hid in a blind situated towards the middle of the bridge? The gulls would be indirectly forced to take a path directly over me. I might actually try this one day.

This individual appears to be an adult at first glance, but is it?

If one looks closely at the outermost primary, you'll notice a black sliver in the middle of the white on the underside of the feather. When the wing is held down, we notice this mark of immaturity even more. Here's a photo of this bird a few seconds later as it banked around the bridge:

2nd cycle Bonaparte's Gull; Definitive adults should have pristine-white outer primaries.
Also, note the blackish markings on the mid-primaries.

By the time adults (and near-adult birds) reach Illinois, they've usually grown out their primaries and secondaries leaving them with a very fresh look. Here's one with the prebasic molt running a bit behind:

It was a beautiful day to be out. I estimated there to be about 130 Bonaparte's on the lake. Not many other lakes in Illinois get these numbers as consistently (Carlyle Lake attracts the most, reaching into the thousands some years). These numbers will continue to increase through early November and then they'll begin to drop off as we get towards Thanksgiving.

16 October 2011

One-footed Gulls

Have you ever seen a gull with an amputated foot? I'm not talking about an individual standing with one leg and the other tucked away like this bird:

I'm talking about a completely missing foot like this guy:

Adult Ring-billed. Chicago, IL; 14 October 2011.

A quick google search of "gull missing foot" will provide tens and tens of hits that describe this unfortunate phenomenon. The culprit? Most times it's fishing line. Like other species that spend a significant amount of time near water, the risks of getting tangled up are prevalent, but even more so with gulls because they tend to gravitate towards fishermen. Most that survive this traumatizing experience seem to eventually manage just fine.

Here are a few YouTube videos that demonstrate this ongoing clash between gulls and fishing line:

Another explanation for missing limbs stems from adults biting newly fledged chicks. It's very common for adult gulls to attack the young of their neighbors, especially if one has wandered out of its designated "space". Here's a great video showing how these "spaces" are established and maintained:


11 October 2011

Loyola Park Franklin's

I never tire of observing Franklin's Gulls, especially on the Chicago lakefront where this species is uncommon. The nice thing about getting Franklin's here is their willingness to allow relatively close views. My experience with this species on the lakefront has been pretty consistent: they allow good initial views upon approach but then they soon become skittish and demand their space. My feeling is that they initially perceive me as an ordinary beachgoer that's walking by, but then when I stop and make eye contact they, naturally, become nervous.

Steve Spitzer found and reported 3 FRGUs at Loyola Park on Saturday, 8 October 2011. Surprisingly, Steve's birds were still there the next evening. I made it out to the park after a brutal battle with post-Chicago-Marathon lakefront traffic. My effort was rewarded with this adult that came right in with a group of Ring-billeds:

Adult Franklin's Gull; 9 October 2011; by Amar Ayyash.

The other two birds were first cycles that seemed happier on the lake and would not get up for me. They sat about 100 yards out as if to take in the scenery of beachgoers and boaters. Here's one of those youngins beautifully captured by Illinois birder Matthew Cvetas:

1st cycle Franklin's Gull; 9 Oct 2011. by Matthew Cvetas

Steve Spitzer refound this same individual today on 11 October 2011 (first seen on 8 Oct 2011). This is somewhat unusual as Franklin's spend no more than 1-2 days at a site when they're seen on Lake Michigan. They always seem to be in a hurry to get where they're going, especially in the spring. Somewhat puzzling is the absence of the adult and the other first cycle individual. Franklin's typically come and go together when migrating but I suppose there comes a point in their journey where certain individuals split off. Could it be that this individual needs more time to refuel? Could its health be compromised? Maybe it's just enjoying this stagnant pressure-system that has been hovering over the Midwest for the last week or so. One Chicago birder reported seeing what he felt was the adult at nearby Fullerton Beach on Monday (the only day none of the 3 birds were reported at Loyola since Saturday); The red tip on the bill was the reference mark used.

Coincidentally, I found a 2nd cycle Franklin's at Loyola Park this past spring and so I'm starting to wonder if this site regularly attracts this species during migration. In any event, these transients will soon finish their transequatorial journey to the southeast coast of the Pacific where they'll winter in and along the Humboldt Current. Here, they'll congregate with hundreds of thousands of other gulls including their mostly sedentary South American relatives, namely Andean, Gray, Gray-hooded, Kelp and Belcher's Gulls. Ah, what I'd give for one of these relatives to accompany our Franklin's back north next year.

Ramble over.