IT鈥橲 not just Desperate Housewives who stray when their husbands go to seed. Female barn swallows will happily cheat on their mates too. But they can also be fooled into staying faithful if their mate is given a plumage 鈥渕akeover鈥� to enhance his looks.
Rebecca Safran and colleagues at Princeton University waited until 60 barn swallows had paired up and laid their first clutch of eggs, before removing them to encourage a second attempt at breeding. This time they captured males before mating and painted the collars of a third of them with red ink to make them as colourful as the collar of the most dominant male. Another third were painted with clear ink, while the rest were left unpainted so that their collars would fade naturally.
Analysis of DNA from eggs in the first clutch suggested that around 70 per cent of eggs were sired by the 鈥渉usband鈥�. But in the second clutch, spruced-up husbands sired 95 per cent of their nestlings, while the other males were cuckolded just as much as first time around (Science, vol 309, p 2210). 鈥淥ur research shows that it really pays to keep up appearances,鈥� says Safran.
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