Showing posts with label sexual selection. Show all posts
Showing posts with label sexual selection. Show all posts
Whydahs and Canaries, Oh My!
In the grasslands outside Nelspruit, South Africa, I enjoyed a day birding with my dear friend Peter Lawson. Lantana was running wild in the tangled grasses, and yellow-fronted canaries were feeding on its fruit. Blue is traditionally a bird-attracting color; plants that "want" birds to take their fruit make blue fruit.
No wonder lantana spreads like mad!
Yellow-fronted canary with common waxbill. The waxbills are just after grass seed.
The stars of the show this day were the pin-tailed whydahs. I'd seen whydahs in winter in South Africa, when they look like little brown house sparrows. Nothing prepared me for seeing the males in full summer raiment, breeding plumage.
They chose prominent perches all around the fields, showing off their spectacular tails.
That's a lot of tail for a little finch to carry. Must be some sexual selection at work here. The boys with the longest tails get the most mating opportunities...something like that must be going on.
Here's the little gal who decides how long the tails will get: the female pin-tailed whydah.
Yes, the males are spectacular, but the females are the ones driving the evolution of their wonderful tails. If female birds decide they like long tails and mate preferentially with long-tailed males, Nelly bar the door. Eventually you get a 5" bird with a 15" tail! And the males were dancing like mad, buffeted by a fresh warm breeze, their tails making sinusoidal curves as they danced.
O glory, what a bird. They landed with a flourish on a prominent high perch, letting their tails do their thing in the wind.
I love this shot of a male whydah dancing above a female (hidden in the grass). He's fluttering in one place, and he closes his wings to his body and just hangs in the air between flaps, looking like some kind of crazy wiglet suspended above the grass tops. Bird displays just knock me out. I can only imagine how cool it looks from below.
Resting between dancing bouts.
And a rattling cisticola cheering them on.
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The Madness of Martins and Elk
Monday, April 23, 2007
0 commentsOn my drive up to Bellville, Ohio on Friday, April 19, I stopped at a favorite haunt: Zanesville Pottery. This is where I get a lot of my bonsai pots and the Ohio-made birdbath pedestals that I use for orchids and planters. Didn't find much this time but I had fun looking, and I decided to cruise north on old U.S. 40, which parallels boring old I-77. Boy, am I glad I did. The first thing I saw was a flock of birds overhead, with a distinctive shape.
There was.
Simply the most magnificent purple martin colony I'd ever seen. Most of the nesting gourds home-grown; the houses, nay-- castles, all home-built.
Friday was the first nice day in about two weeks. The martins were chortling and basking in the unaccustomed spring sunshine. They looked so happy, and they sounded happy, too.
Whether or not you buy this evolutionary just-so story, I have definitely seen some people who are responding to selection pressure by the opposite sex in ways that are not adaptive. Like women, trying to run on stilettos, and falling down and breaking an ankle. Or wearing skirts so short they can't even bend over or sit down. Or acting dumb and helpless and trading solely on their looks. Or putting bags of silicone and saline on their chests. (How do you nurse a child around that?) Like men, trying to drive the hottest cars the fastest, thinking to impress women, and wrapping themselves around telephone poles. Jumping off bridges secured only by bungee cords. Shooting whitewater rapids nobody ought to mess with. Irish elks, all. Pfffffft. That's my lecture for the day. And I plod off to cook dinner for the bearers of my genetic material, wearing homely, sensible shoes and khakis, and thinking about Irish elk.
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Labels:
Irish elk,
purple martins,
sexual selection
Tuesday, August 21, 2012
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