Human females no different to birds and fish when it comes to 'mate-poaching'

Newscientist.com: The most striking result was in the responses of single women. Offered a single man, 59 per cent were interested in pursuing a relationship. But when he was attached, 90 per cent said they were up for the chase.

SHOOT: Fascinating article. It reminds me of a conversation I had with my sister a few years ago.
Me: How come you are ALWAYS in a relationship?
Candice: How come you're NEVER in one?

clipped from www.newscientist.com Burkley and Parker speculate that single women may be more drawn to attached men because they've already been "pre-screened" by other women and found to be satisfactory as a mate, whereas single men are more of an unknown quantity. Burkely said that similar mate-poaching strategies have been reported in birds and fish. But previous studies of people had only asked whether participants found other potential partners attractive, so she designed hers to specifically probe whether participants would pursue a relationship. "The next question is why," says Burkley. So in further studies, she plans to further explore women's motives for pursuing "taken" partners. Apart from the explanation of "pre-screening", another possibility, she says, is that in US society, women are socialised to be competitive, so they derive self-esteem by mate poaching from rival women. Men were keenest on pursuing new mates, but weren't bothered whether their target was already attached or not.