Understanding Bird Behavior: Feather Maintenance

Feather maintenance is one of the most important activities in a bird’s day; clean and healthy feathers are necessary for flight aerodynamics, body insulation, and territorial/courtship display. Feather maintenance involves several different activities including preening, bathing, sunning, oiling, and anting.

Preening –
Birds preen their feathers to clean them, removing dirt, stale oil, and parasites. The bird fluffs up the feathers and then combs them with its bill, usually one feather at a time; this action removes dirt from the barbs and smooths them so they will lock together properly. Birds use their feet to scratch areas like the head and neck that can’t be reached with the bill. The inability to carefully preen the head explains the appearance of “bald headed” cardinals in late summer. Feather mites, easily removed from body feathers by preening, destroy the feathers on some cardinals’ heads and the bird appears to be bald until its molt in the fall when all the feathers are replaced.

Bathing –
Birds bathe to clean feathers or to wet feathers for easier preening. Most birds use water for bathing but some species, including house sparrows, use dust. Birds bathe using various techniques – some sit in, or at the edge of, a birdbath, puddle or other body of water and dip themselves throwing water over their bodies; some roll on wet leaves or in wet grass; some fly through the rain; swallows fly over a body of water and skim the water surface to wet the body; I have observed hummingbirds in my backyard flying through the sprinklers.

Sunning –
I have often seen birds, especially cardinals and blue jays, on my deck rail tilted to one side with ruffled feathers and spread wings and tails. These birds were sunning themselves. Although ornithologists aren’t sure why birds sun themselves, they assume they get the same benefits from the sun that humans do.

Oiling –
Most ducks and geese waterproof their feathers by oiling them; as the bird preens, it transfers oil to its feathers from a gland at the base of its tail.

Anting –
This seems like strange behavior indeed: Birds allow ants to run through their feathers or they pick up ants with their bills and rub them over their bodies! Flickers and blue jays have been observed sunning in an anthill presumably allowing ants to crawl in and out of their feathers. Bird biologists are not sure why birds “ant” but presume that acidic secretions from the ants discourage or eliminate parasites.

All these maintenance behaviors ensure clean and healthy feathers which are important for the bird’s ability to fly, to maintain its body temperature, and to defend its territory with display.