Water off a duck’s back
A phrase that came to mind on a recent long journey home from holiday, driven in torrential rain.
It’s generally accepted that ducks are waterproof and shed water easily, but I confess it’s not something I’ve ever given a lot of thought to. A duck’s front is waterproof too. Underneath the waterproof outer feathers is a layer of fluffy down feathers that trap air. This not only insulates their body from cold air and water and keeps them warm, but it also provides buoyancy to keep them afloat. As it will for dunnocks and doves too, should they find themselves briefly immersed!
Feathers are engineering marvels, constructed from a hollow central shaft with a vane made of barbs that zip together and repel water. As well as being tightly zipped-up, a layer of water-proofing oil is applied during the hours spent preening each day. With deft beak movements (hard to imagine with a duck’s spatula-shaped bill, but not the pinpoint bill of a robin) any vanes that have become unzipped are carefully rearranged, then smeared with the oil produced from the bird’s preen gland. This is located at the base of its tail, which is why they appear to be rummaging behind them, then poking amongst their breast feathers and under their wings. I dare say they have a good scratch too while they’re at it as, like all animals, they will carry blood-eating parasites – and feather mites that will feed on the feathers themselves.
A word of warning, though, if you put food out to help your garden birds through the worst of winter weather. It’s important that any scraps from the table (or from cooking) that have vegetable oil are avoided. As oil remains liquid, it will interfere with the birds’ natural preening oils. This could be fatal for a bird trying to remain dry, and therefore warm, in wet weather. Fat (such as lard or suet) remains solid so is not a risk to the birds’ plumage and is loaded with calories. However, if this has come from cooked meat it is likely to carry a high concentration of salt so, as birds cannot process salt, fat straight from the roast tray should be avoided too.
The good news is garden birds love crumbled Christmas cake and pudding. So, do your waistline a favour by giving your second helping to them.