Why Do Birds Take Baths?
Birds love having water around for bathing and drinking. Birds lose water through respiration and in their droppings. Most small birds need to drink at least twice a day to replace the lost water. Birds get the liquid they need from their food and by drinking. Many insectivorous birds get most of their water from food. Seed-eating birds have a dry diet and they do need to drink more.
Water is particularly important during the winter when natural supplies may be frozen and in hot weather during the summer when water can be hard to find. They may also drink water droplets that form on leaves, especially if they live in woodland. Aerial species such as swallows and swifts swoop down onto a water body and scoop up a beakful of water while still in flight.
Most birds drink by dipping their bill in water and throwing their head back to swallow. Pigeons and doves are able to immerse their beaks and can drink continuously.
Water to bathe in is just as important for birds, especially in winter. It is essential that they keep their feathers in good condition. Bathing is an important part of feather maintenance. Dampening the feathers loosens the dirt and makes their feathers easier to preen.
When preening, birds carefully rearrange the feathers and spread oil from the preen gland so they remain waterproof and trap an insulating layer of air underneath to keep them warm. There are very basic descriptions of the mechanics of bird bathing, an experimental examination of wetting and drying of disembodied feathers, suggest that bathing plays an important role in feather maintenance.
Feathers are a bird’s lifeline: they insulate, waterproof and, of course, provide the power of flight. Feathers get replaced once or twice a year. In the interim, they need to be kept in good condition. The sun, feather-munching mites, bacteria and gradual wear take a toll on feathers. A set of year-old flight feathers look like they’ve been through the ringer: they are frayed and dull.
A good bath may keep those precious feathers in the best condition possible for as long as possible. But maybe we were ignoring another important aspect of habitat quality – access to bathing water and baths might play a role in survival too. Until we get an answer from science, we will need to rely on common sense and keep those backyard bird baths full.