Yes, birds do preen themselves. Preening is an important part of a bird’s daily routine and serves several purposes. When birds preen, they use their beak to spread oil secretions from a gland near the base of their tail over their feathers. This oil helps keep their feathers conditioned and waterproof. Preening also helps birds straighten, clean, and realign feathers that may have moved out of place. In addition to practical functions, preening reinforces social bonds among some species of birds that preen each other. Let’s explore the details of how, why, and when birds preen their feathers.
How do birds preen?
When birds preen, they use their beak to distribute oil from their uropygial or preen gland over their feathers. The preen gland is located near the base of a bird’s tail and produces an oily secretion. To preen, a bird rubs its beak against this gland to collect the oil. The bird then rubs its beak over its feathers, spreading the oil. The oil conditions the feathers, keeping them flexible and waterproof. It also contains antibacterial and antifungal properties to help feathers stay clean and free of parasites. In addition to spreading oil, preening involves using the beak to straighten feathers, remove debris, and rezip barbules if feathers have moved out of place. Birds may also preen by scratching hard-to-reach spots with their feet and rubbing against objects. Preening is a maintenance ritual that consumes a good portion of a bird’s day.
Preen gland
The preen gland, also called the uropygial gland, is a small gland near the base of a bird’s tail. This gland secretes an oily substance that birds spread over their feathers while preening. The exact composition of preen oil varies somewhat by species, but generally contains water, fat, and wax. It may also contain volatile organic compounds, fatty acids, esters, alcohols, cholesterol, and fat-soluble vitamins. The oil moisturizes feathers, keeps them arranged neatly, waterproofs them, and helps maintain flexibility. It also has antimicrobial properties from fatty acids that deter parasites, fungi, and bacteria. The preen gland size varies based on species and sex. For example, the gland is larger in aquatic birds like geese that need extra waterproofing oils. The gland shrivels outside of breeding season when oil production decreases.
Feather maintenance
Preening maintains feathers in several ways. The preen oil conditions feathers to remain flexible and water-resistant. It also helps realign feathers that are out of place to maintain insulative and aerodynamic functions. In addition, preening removes dirt, parasites, old oil, matted feathers, and broken feather bits. This cleaning action helps prevent damaged feathers or debris matting that could otherwise impair plumage. By removing foreign particles, preening may also help prevent infections. Preening reinforces the tiny hooks, called barbules, that zip adjacent feather strands together. Zipping the barbules smooths the feather for optimal air flow. Unzipped feathers can mat and lose insulating capabilities. Proper preening is essential for healthy feathers.
Why do birds preen?
Birds preen for several important reasons:
Clean feathers
Preening cleans feathers by removing dust, dirt, old oil, and parasites. This cleansing helps maintain the structure of feathers and prevents damage or matting. Keeping feathers clean and neat is essential for healthy plumage.
Condition feathers
Preen oil conditions feathers to be supple and water-resistant. This preserves feather structure and function. The oil’s antimicrobial properties also deter microbes that could degrade feathers.
Align feathers
Preening straightens feathers and rezippers the tiny hooks that connect them. Aligned, interlocked feathers preserve insulating and aerodynamic properties.
Reinforce social bonds
Social preening, in which birds preen each other, cements social bonds and hierarchies. The primping reinforces friendships and family ties.
Comfort
Preening serves as comfort or entertainment between other activities. The preening motion may have a soothing, smoothing effect.
When do birds preen?
Birds preen at various times throughout the day. In many species, preening is one of the most common daily activities after eating and sleeping. Birds tend to preen most actively at the following times:
Morning
Birds straighten out their ruffled feathers after waking up. This morning preening session primes the feathers for the day.
Throughout the day
Birds preen occasionally during the day between activities like singing, foraging, and resting.
Before roosting
Many birds do a final preening session right before settling in to roost for the night. This readies feathers and redistributes protective oils.
During molting
Extra preening helps birds groom old, loose feathers out during molting. The increased preening helps condition new emerging feathers.
After wetting
Getting wet compromises feather structure, so birds preen immediately after swimming or getting caught in rain. This readjusts feathers and reapplies waterproofing oils.
When agitated
Stress or anxiety can trigger extra preening as a displacement behavior. The act appears to have a calming effect.
What activities are associated with preening?
Birds often combine preening with other maintenance activities:
Bathing and water-preening
Some birds bathe by splashing in shallow water or dew before preening. This loosens dirt so preening can remove it from feathers. The moisture also reactivates preen oils so they spread over feathers more easily.
Sunning
Sunning heats up the preen oil so it penetrates feathers better. Some solar energy may also degrade microbes and parasites on feathers.
Dusting
Dusting in dry soil or sand absorbs extra oils and debris. The grit also stimulates the skin in a satisfying way.
Anting
Some birds rub insects like ants over their feathers to possibly deter parasites or gain antimicrobial oils.
Allopreening
Social species allopreen by grooming each other’s head and neck. This reinforces social bonds.
What are some interesting preening behaviors in specific bird groups?
Water birds
Water birds like ducks and geese have large preen glands to secrete extra oils. Their dense, water-resistant plumage requires additional preening. Diving water birds may submerge while preening to reactivate the oils.
Parrots
Parrots use their beaks like comb and brush to meticulously align feathers. Their dexterous feet allow them to scratch hard-to-reach spots.
Raptors
Raptors bath by lying in shallow water and vigorously flapping wings before preening. Bathing rehydrates feathers for preening.
Herons
Herons preen using powder down – specialized feathers that disintegrate into a fine powder. They smear the powder on wet feathers to dry them.
Frigatebirds
Male frigatebirds balloon their scarlet throat pouches while preening to attract females. The flashy pouches signal fitness.
Flamingos
Flamingos secrete reddish preen oil that stains their feathers pink. The vibrant color comes from pigments in their food.
Penguins
Penguins preen using specialized comblike feathers on their wings to align and condition their dense, waterproof plumage.
Conclusion
Preening serves essential functions for bird health and feather maintenance. Birds use preen oil to clean, condition, and waterproof their plumage. Frequent preening straightens feathers for proper airflow and insulation. For social species, preening reinforces social bonds. Birds dedicate much of their day to meticulously preening their feathers to keep them in prime condition. Proper preening allows birds to optimize feather function, warranting the time invested in this important behavior.