A recent study explains why all women seem to swoon over men with foreign accents.
Well actually, a study on spotted hyenas found that at least in some species, females really do prefer foreign males.
Scientists working in Tanzania tracked the reproductive success, or number of cubs fathered, of male hyenas. The scientists used genetic paternity tests to determine which male had fathered each cub born in the eight clans during a ten-year study period.
Hyenas live in social groups called clans. Most, but not all males, leave the clan into which they were born. Females, on the other hand, rarely leave their birth clan.
Using the genetic markers, researchers found that almost ninety-percent of the females mated with males that had immigrated from another clan, or were born into the clan after the female was born. In other words, females preferred to mate with males that they didn't recognize as being from their birth clan.
Since young, inexperienced females were less likely than older females to recognize the males from neighboring clans, males looking for mates were most successful if they moved to a clan with lots of young females.
By having a "rule" that unfamiliar males are better, females can usually avoid inbreeding, without needing to evolve a more elaborate mechanism to identify close relatives.