Wednesday, 31 January 2007

Duck tales

Although I am the world's second worst birdwatcher*, I can tell my Anas from my eider. I'm not sure which came first—a fondness for ducks or the ability to tell them apart—but one inevitably led to the other. Whenever ducks are around, I have my binoculars glued to one eye and the camera to the other**.

Blue-billed ducks (Oxyura australis) are among my favourites. They're pocket-sized birds with tails that look as though someone's shut them in the car door. They're closely related to the stifftails (ruddy ducks, white-headed ducks and others), all of which are characterised by the sparsely-feathered fan-shaped tail that's either laid flat on the water's surface or held vertically on display. (Or at 45 degrees. Darned birds not posing properly!)

These ducks are also known for another characteristic — a penis of prodigious proportions. Kevin McCracken produced a paper on the drakehood of the Argentinian blue-billed duck (O. vittata). He speculated not only on the reason for its length (at more than 30 cm, it's almost as long as its owner) but also for its weird shape (coiled with spines and bristles). It's probably best that you read the original articles from Auk and Nature (both PDF) because I'm struggling to hold back a torrent of puns. And the occasional unfortunate typo.
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* The world's worst birdwatcher is a friend who not only mistook a mooring buoy for a pelican but also confidently identified a little pied cormorant among a group of little black cormorants. What was wrong with that? Well, when the white-fronted bird moved, it became obvious that it was, after all, just another LBC ... and the white was a streak of cormorant shit on the rock.

** Apologies for any mental images of Marty Feldman generated by that moment of hyperbole

6 comments:

budak said...

Always knew ducks, sorry drakes, had it good!:P

Darky said...

Struth, indeed!
A transparent ploy to generate more traffic, I fancy!
I don't think those poor well-hung quackers will be getting much relief from prying eyes for a while.

The hand-waving statement in the Auk article that "geese tend to copulate on land" is a bit loose.
Ducks will also tend to copulate on land if they are deprived of water, and conversely geese prefer to do it on the water if it's available.
My experience is that fertility in heavy breeds of domestic geese is reduced when they don't have access to water, however it looks like these Argentine Lake Ducks would have zero fertility on land!

Olivia Judson's excellent Dr Tatiana's Sex Advice to All Creation has a great bibliography on all forms of sexual competition - - for us amateur readers.

Snail said...

Ah, the comments are working again!

I thought you might appreciate this post, Budak!

Darky, you've rumbled my little ploy. Actually, I was a bit mindful of what sort of traffic I might get. Not to mention how disappointed some people might be when they found out what the post was really about. But I was much more concerned with the possibilities of typos. I screened the text several times ...

Duncan said...

Strike me, made to feel inadequate by a flamin'duck. ;-)

Snail said...

I want to know about pink-eared ducks. Y'know, if it's true about beak size and ...

Duncan said...

Aha, you're a woman of the world Snail. :-)