Tuesday 31 May 2011

Drinking birds

You're never far from a dove in East Africa, and if you sit by a waterhole waiting for something exciting to drop in, you might spend a little time point out how birds drink. Start by watching the clouds of quelea often around (don't forget to talk about them too, since they're fascinating birds we'll have a blog on later!).

Clouds of Red-billed Quelea drinking in Tarangire NP, May 2011

As they come in to drink you'll see them dipping their beak into the water, tipping their head back and letting the water flow back to their crops then repeating the process. Most birds drink like this - they can't suck as we can, so have to 'sip and tip' to do so. But there are some exceptions, one of which is pretty sure to turn up at every waterhole within a few moments of you: Doves (also sandgrouse, which we believe to be closely related to doves, and a few parrots).

Not drinking (sorry) but an Emerald-spotted Wood Dove in Kruger NP, May 2011
Watch a dove drinking and you'll see it open it's beak slight underwater, and then just keep it's head there as it uses capiliary action to pull the water into the beak, then it's tongue as a piston to pump water into its throat. It's a very different drinking action that will be immediately obvious. And it was obvious to many naturalists in Europe a long time ago - most birds lift their beaks to heaven to give thanks to God for the water between each sip, but those ungrateful doves must have something to do with the devil because they keep their heads down the whole time... Unfortunately I can't find any more details of this superstition online, because google dove, drinking and heaven and you find far too many links to the Biblical references to the dove (the closest is here). But it's still a good story!

And, of course, if you should happen to see a sandgrouse come in you'll see the same drinking, but you might also see the males (only males apparently) filling their specially adapted breast-feathers to take water back for the chicks. Their dry, seed-filled diet means all sandgrouse have to drink daily, and estimates suggest that in the driest times of the year adults may fly a round trip of up to 160km from the nest to waterholes in some species. Even though they are very fast fliers - they can easily do 70kph - that's still a long trip! (Sandgrouse facts from here, but you probably won't have free access.)

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