In the Kgalagadi, bateleur eagles can often be seen spending quite some time at waterholes during the heat of the day, frequently entering the water for a bath and then opening their wings to sunbathe. They are locally common in protected areas but because they require large territories, they do not do well elsewhere and are regarded as vulnerable in southern Africa. Bateleurs and other eagles lie on the ground with their wings spread. This exposes the wing feathers to direct sunlight, warming the oils in the feathers, which the bird then spreads over the feather with its beak to improve its aerodynamics.
This, however, is not the only reason for lying on the ground. Ants crawl over the wings and feathers, collecting bits of leftover food, and dead feather and skin material. When covered in ants, the bird then ruffles its feathers, startling the ants, which react by secreting formic acid as self-defence. This in turn kills the ticks and fleas, ridding the host of its parasites.