Saturday 3 January 2009

More moorhens

Teenage moorhens feed their younger siblings. Not only that, but in some species they also sit on eggs and chase off intruders. They probably even keep their bedrooms tidy and are unfailingly polite to other members of the family. Teenage moorhens set an example to us all.

Teenage dusky moorhen (Gallinula tenebrosa) looking for an old bird to help across the pond

But why are they so helpful? There are numerous hypotheses about the roles of different individuals in co-operative breeding. The benefit to the youngest chicks is obvious — they get care from siblings as well as parents. The benefit to the parents is also pretty clear. But where does that leave the teenagers?

Moorhen chick prepares itself for teenage-hood.

On the lookout for more food

Here's my hypothesis. Feel free to test it. Maybe they're just rebelling against their parents who live in communes and engage in a spot of free love. That's right — it's always the 1960s for moorhens. Given that they lay their eggs in shared nests, not only are the males not sure which chicks belong to them, but neither are the females. This is the stuff of A Current Affair. Teenage moorhens, according to my hypothesis, are the stockbroking kids of the hippy generation.

Adult taking some responsibility for its actions. Or possibly that of another pair. Who knows? Certainly not this moorhen.