Naturespeak A naturalist's view of the world

June 22, 2012

Little Hellians

Filed under: Uncategorized — wykes @ 1:54 pm

I’m not sure why, but Pied-billed Grebes are often referred to as “Hell Divers.”  They don’t look especially nasty and they live in cool water, so the whole idea is rather lame. Technically, they don’t even dive. It makes for a good title, however. When you add the word Hell to anything it adds immediate interest (Hell children, for instance, are more fascinating than just children).  Grebe children – aka baby grebes – should be called “Hellians” if we stick to this formula, but they really look and act more like confused little stripy chicks.

I came up several sets of confused little stripy Grebe chicks at Pointe Mouillee recently and was lucky enough to digitally bag a set – along with their mom. The attending adult in this case displayed the usual traits of the species.  The adult birds (both male and female) look alike in their plainness. Both are chunky chicken-like birds with a light coffee-with-cream brown complexion.  They have long necks and virtually no tail (this part being reduced to a pathetic tuft of feathers). During the breeding (hell season) they have a black chin beard and a light blue bill circled with a dark band.

This bill feature is the reason behind their common name of Pied-billed Grebe. “Pied” refers to the two color bill. Although “Pie-bill” would be easier to say and write, the name is “Pied-billed” and that is that (hell of a name, eh?).  It is useful to think of them as “Pie-bills” in an odd sort of way because their bill is wedge, or pie, shaped. Theirs is a beak more akin to that of a chicken.  It is a beak used for feeding on fish, crayfish, and aquatic insects.

Young grebes do not look like their parents at all. They are marked with a wonderful array of dark and light stripes and a red face patch. This patterning probably serves to camouflage their outlines when among cat-tail and reed stems. Born atop floating mats of vegetation, the chicks leave their nest immediately upon hatching but do everything they can to stay out of the water – including riding mom’s back whenever possible.  I can say with some small bit of authority that they are slow to develop their diving abilities.

The chicks pictured here were obviously alarmed by my presence (note the “what the hell!?” look). Instead of doing the usual Grebe thing, which I will explain in a moment, they swam around in circles. It soon became apparent why they didn’t dash for the cover of the nearby cat-tails when mom bobbed to the surface. She had ducked out of sight when I arrived and they were waiting for further instruction.

 

Grebes are champion submerged swimmers. Once they get a handle on their technique they can swim great distances under water. Instead of actually diving, they simple submerge in the manner of a submarine. When they go down the last thing remaining above the water is their head (as opposed to other avian divers which leave you with a view of their hind end as they descend).  Here are a few pictures (below & here) of another adult grebe in the process of sinking. This behavior is a great identifying feature when you see one of these small marsh chickens disappear from a distance.

In order to submerge, Pied –billed Grebes are able to adjust their buoyancy by compressing their feathers.  Already possessed of rather dense bones, they can choose their sinking depth by forcing air out from beneath their feathers. Often they submerge to the point where just their heads remain peering out and they will swim for a while in this position.  Otherwise, they will sink and swim.

Unfortunately, the little hellions in these pictures were unwilling, or unable, to follow their mother’s lead when she initially sunk out of sight. They milled about until she returned to guide them to cover via the surface route. No doubt the family engaged in some submarine practice after I left. So, the next time I see them I won’t see them (what in the hell did I just say?).

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