There’s a lot more to the humble dunnock than meets the eye. Modest in appearance, shy in its behaviour, charming in its song. It is an archetypally feminine bird.
Dunnocks are polygynists. Or polyandrysts. Or polygynadrysts. Which means that they typically have more than one mate. They are the very model of a modern avian, sharing partners in a free love scenario. Perhaps one male has two females; but more likely one female might have two males. Or maybe three or four have three or four others. The dunnock seems a liberal minded bird.
Which is not to say that all are equal in the dunnock world. There is as likely to be an alpha male in the dunnock household as in most other arenas. But that doesn’t mean the beta male must bide his time. The female is quite likely to nip out for a bit o’ lovin’ while the top bird isn’t looking. It’s not that she’s not fussy: rather she likes to ensure that she dips her beak, so to speak, into the best gene pool. And dip she does. Dunnocks are likely to mate up to twenty times a day. Jealousy doesn’t seem to come into it. If she mates with both males, both are likely to help out with raising the chicks.
The female dunnock has another clever trick she can deploy. If she should mate with one male and then find another she fancies, she can expel the first bird’s sperm so that the second has a better chance. He in turn is happy to think his genes are in the ascendancy.
The end result might be a dowdy little bird, albeit with a marvelous gift for song. But they’ve found a way to make ‘free love’ work, on the female’s terms. And there’s something in that.
Image by Dennis, Creative Commons