Wednesday, November 03, 2010

The Wildlife Mall and What IS a Kettle?

Remember the strip mall that hosted Wiley Mallard Hen and her ten ducklings? Well it seems that whenever I visit for printer paper or a cartridge of ink there is always an avian episode. Sometimes nominal and sometimes not.

Today, first off it was an American Crow having lunch on the roof. I have noticed that quite a number of avian species seem to be partial to those flat roofs for dining. I suppose that if the food in question is bigger than bite size, branches being roundish and hence not terrific tables unless they're quite old, and who knows what can happen if you take a leisurely lunch on the ground, a nice flat roof is a dandy option. There's a 360 degree unobstructed view and as many of these malls were only just recently corn fields or pastures, the roof perch makes you king of the mountain.

Crow gives me a perfunctory look.

Then it's back to fine dining at the rooftop cafe. I go in for my paper, come out, and am getting into the car when suddenly all hell breaks loose as birds start screaming.

I pop back out of the car, and there are two young gulls having a severe quibble over some edible right where I'd just walked not 15 seconds before.

Above me and the two screechers are, seemingly out of nowhere- I could have sworn they weren't there when I came out, a flock of gulls.

And of course being gulls, they're all putting their two cents worth in, at the top of their syrinxs.

While dipping, wheeling, and swooping about.

Then as suddenly as they appeared, they wheeled off and disappeared.

Speaking of gulls, here's the group that lured me into finding the bird feeders near Woodman's the other day. Karen Anne Kolling of Rhode Island left a comment on that post--"kettle up?"

I most often see it, kettling I mean, done by Turkey Vultures but other birds such as gulls do it as well. They circle, swirl, wheel, glide, even flap now and again riding the geothermal currents in what looks like some kind of organized activity.

What you see is called a kettle.

And a bird ascending in the kettle is kettling up or one could say they as a group, kettle up.

Okay, I may have made that up in the moment, turning the noun into a verb, but there is quite a bit of precedence for that so I'm going with it.
Conceivably, once one knows what a kettle is, the words kettling or even the use of kettle up, makes sense.

And there is a second issue--I suspect the angle and the lack of a third dimension is the culprit, but a photograph of a kettle never really looks like a kettle of birds does in the moment.
One needs to see one live to get the real feel of it.
Then you might ask, why the word kettle, in the first place?
There is some dispute as to just how the usage originated. Some say it is because the birds look like boiling water in a kettle as they swirl around and others think it is the birds themselves who outline a kettle in the sky.
I have my own opinion but I'm not telling.
It is the time of year when kettles are quite common so go have a look for yourselves and see what you think.
We've had-- why the name? Now how about-- why do they do it?
It is thought that vultures kettle as a cue that they are ready to migrate.
Though when I've seen any number of species kettle, it appears to me like a very visible way to gather the clan for the next leg of the trip, or to group roost or whatever and not necessarily only just gathering the clan for the original take off to migrate.
Perhaps that's a problem of semantics.
Also turkey vultures are very heavy birds after eating and have trouble even getting off the ground after a heavy meal. Therefore finding some nice geothermal currents could make the difference in getting up in the air or just standing around for a couple of hours digesting on the ground if there is a calm.
Then there is also the example, if you watch there seems always to be an example that doesn't really fit the cut and dried definition of a behavior.
At any rate, a few weeks ago I saw five Turkey Vultures and three Red-tails seemingly all kettling in the same geothermals. Were they all trying to attract others of their species to migrate? Or perhaps they kettled to get some altitude without having to flap their tails off and use up all those calories?
Perhaps they even had different reasons for being there and were just going about their own particular species business without interfering with the second species.
Good geothermals can be hard to find some days.
The Red-tailed hawks did not appear to be herding the vultures out of a territory which is a common interaction between the two species. In fact once two RTHs who were near each other reached a certain height they flew off to the east. The third RTH, kettled up for a bit longer, got to about the height in which the first two had exited the kettle and then the third left to the east as well.
The Turkey Vultures, on the other hand just kept swirling for as long as I watched.
"Different strokes..."
Donegal Browne

No comments: