Male hamsters’ urge to mate is switched on by the same chemical that triggers puberty in humans.
Greg Demas at Indiana University in Bloomington and his colleagues found that the peptide kisspeptin is involved in switching fertility on and off in Siberian hamsters (Phodopus sungorus), which only breed in summer. In winter, male hamsters change colour, their gonads retract and they have no libido. Kisspeptin is one of the triggers for human puberty (Â鶹´«Ã½, 22 July 2006, p 34).
One group of male hamsters was exposed to eight weeks of long, summer-like days and another group to short,…
