Showing off for nothing

04september2013
Source:sciencemag.org
Male strawberry poison-dart frogs work very hard to conquer females. Vying for mates, they make constant, loud vocalisations. A new study, however, demonstrates that all that hard work is just not necessary.
Despite the best efforts of the courting males, female strawberry poison-dart frogs (Oophaga pumilio) simply choose to mate with the nearest male. The period in which the eggs can be fertilised is short, so allowing pairing with neighbouring males prevents them from remaining unfertilised. Although the behaviour of the females seems careless, write the investigators in Frontiers in Zoology, it is an optimal choice. The males are continually fighting for territory, so any male who has already conquered a territory is a winner—and therefore a good candidate for mating. Why seek a mate far away when the man next door is just fine?

It turns out that the effort the males put into their vocalisations is not completely useless: females must be able to hear them and find them. Shy, silent types don’t get dates...