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Swallows Shed New Light on Looks vs. Testosterone
Posted by Benny Bleiman on June 11, 2008
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A new study of barn swallows has shed fascinating light on the link between appearance and the levels of sexual hormones in their bodies. Scientists have long noted that male swallows with deeper red throats attract more females and have higher levels of testosterone. Conventional wisdom assumed that swallows born with more testosterone had deeper…