Birds don’t only use water for cleaning themselves, they also ‘sand bathe’. This is a rather interesting phenomenon to observe and so it is worth leaving open sandy patches in your garden. A variety of birds use the fine loose sand to keep their feathers in peak condition and to reduce the number of parasites in them. I first noticed the Laughing Doves doing this in our garden.
Small flocks of them congregate in sandy areas to scoop up the sand with their wings. They then shake their wings, allowing the sand to penetrate between the feathers. Allied to this is the habit of sunbathing, which is when the birds lie down with their wings outstretched. The sun is thought to straighten the feathers and at the same time spread the preen oil throughout the feathers. Olive Thrushes also engage in this kind of sand bathing.
Dust bathing helps absorb any excess oil and also removes dry skin and other debris. Ostriches sand bathe too.