Air Date: Week of January 14, 2005

Living on Earth’s Jenn Goodman reports on insects taking the easy way out when it comes to giving gifts.

Transcript

CURWOOD: Every week, Living on Earth brings you stories about the environment. Now, it's your turn to share a few of your own. We invite you to send them to us in a brief recording. Just visit Living on Earth dot org for complete details. We'll tell you how to make a recording, which could be as simple as picking up the telephone - or sitting down with a friend and telling it with a tape recorder running. Maybe it's a story about trolling for a bit of the country in the big city.

MALE: They say you don't fall into the East River in New York City - you slide in. So when I took up fishing in it from my apartment window, friends said that if I wanted to invite them for dinner, we'd be eating out.

CURWOOD: We'd be eating out. So, what's your story? A selection of stories and excerpts of stories will be chosen for production and posted online and may be broadcast. Now, this is not a contest. There are no winners or losers. It's simply a call for self-expression. Visit Living on Earth dot org for directions, sample submissions and a chance to tell your story.

Just ahead: closing in on the possible culprits behind prostate cancer. First, this Note on Emerging Science from Jenn Goodman.

[SCIENCE NOTE THEME]

GOODMAN: There's new evidence that romance is dead—at least in the insect world.

Authors of a study in the latest issue of Current Biology conclude that male dance flies bearing false gifts can easily fool females. The trickery involves the ritual of nuptial gift-giving—a common courtship ritual among many species in which males present females with tokens of various sizes and value to increase the chance of copulation. But researchers found that dance fly females are just as likely to accept worthless or inedible tokens that only resemble valuable items as they are to accept the real thing.

In a series of experiments, scientists replaced the edible prey that male flies would generally present with either a large edible gift, a small edible gift, or an inedible cotton ball. They found that the pairs of flies with the large edible gifts copulated the longest. But even females who received cotton balls allowed males to copulate for the same amount of time as if they had been presented with the smaller, though edible, gift.

Because it would be advantageous for males to invest less energy in obtaining nuptial gifts, scientists speculate that males may learn to exploit the females' apparent lack of preference, thus giving rise to a whole new culture of worthless gift-giving. Researchers also observed the next logical consequence of this behavior: re-gifting. After terminating copulation, one male was seen to fly off with his cotton ball and re-gift it three times to three different females in 20 minutes, possibly a new record for any species.

That's this week's Note on Emerging Science, I'm Jenn Goodman.

CURWOOD: And you're listening to Living on Earth.

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[MUSIC: James Brown "Funky Drummer" In the Jungle Groove (Polygram) 1986]