The Australian splendid fairy-wren has a peculiar way of passing on its genetic material. It starts off in a manner that might seem familiar to anyone who’s seen a 1950s family sitcom: Boy meets girl, boy partners with girl for life, boy and girl raise family together. But that’s where the similarities end. After the baby wrens grow up, they don’t pair up with other wrens right away; instead, they help their parents raise the next brood. Except that next brood is likely not the true genetic offspring of the “father” of this family. You see, while splendid fairy-wrens do pair up in family units for life, they rarely mate with their original partners. Instead, both males and females like to get together for dangerous sex with other wrens, who in turn may be socially paired with other wrens. And calling this sex “dangerous” may be only a slight exaggeration. Science writer Rob Mitchum blogged last week about research showing that these tiny wrens not only mate primarily outside the family unit, they may be more interested in mating in the presence of one of their primary predators, the butcherbird.
more from Dave Munger at Seed here.