Preening is an important behavior for birds that serves multiple functions. When birds preen, they use their beak to distribute oil secreted from a gland near the base of their tail across their feathers. This oil helps keep the feathers flexible and waterproof. Preening allows birds to align and clean their feathers, remove parasites, and maintain feather integrity. Let’s explore the details of what preening accomplishes for birds.
Distributes Oil Across Feathers
One of the main functions of preening is to spread oil from the preen gland across the feathers. The preen gland, also called the uropygial gland, is located at the base of the tail. It secretes an oily substance made of waxes, fat, and water. When birds preen, they nibble feathers between their beak to transfer small amounts of this oil onto the feathers.
Applying preen oil waterproofs the feathers. Oil causes water to bead up and run off the surface of the feathers instead of soaking in. This is important for keeping the feathers dry and maintaining the ability to fly. Wet, matted feathers are heavy and inhibit flight. Waterproofing also provides insulation. When feathers repel water, trapped air spaces remain intact for better insulation against cold temperatures.
The preen oil keeps feathers flexible as well. Without oil, feathers can become brittle and are more prone to breaking. The flexibility allows feathers to properly align and maintain their structure. Properly aligned, flexible feathers enable smooth airflow over the wing surface for aerodynamic flight.
Aligns and Cleans Feathers
Along with spreading oil, preening aligns and interlocks the tiny barbs that make up feathers. The barbs have even smaller hooks called barbules that attach them together. Preening ensures the barbules remain locked so the feathers create smooth, continuous surfaces. Any out-of-place feathers can be realigned.
Preening also removes dirt, parasites, and other debris caught among the feathers. The preening action loosens particles that can then be removed or fall away. Birds will sometimes scratch with their feet to further dislodge stuck debris while preening. Maintaining clean, aligned feathers is essential for healthy plumage.
Removes Parasites
Birds face a constant battle with parasites like lice, mites, and fleas that live on feathers and skin. Preening helps remove these pests. As birds nibble and sort through feathers, parasites get crushed or swallowed. Certain chemical properties in preen oil may also discourage or kill parasites.
Removing parasites is critical for birds to avoid health problems caused by infestations. Parasites feed on blood, skin, and feathers. This can cause anemia, skin irritation, damage to feathers, and secondary infections. Severe cases can even kill birds if untreated. By preening, birds actively limit parasite loads.
Maintains Feather Condition
The activities involved in preening all help maintain feathers in good condition over the long term. Keeping feathers oiled, clean, and aligned preserves their integrity. This ensures feathers adequately provide functions like flight, temperature regulation, waterproofing, and display for mating.
Over time, feather barbules can start to wear and detach. Ubiquitous preening causes birds to continuously realign and reconnect the tiny hooks. Small amounts of damage can be minimized so feathers last longer before needing to molt and regrow.
Preening also pulls out any feathers that are no longer salvageable. Birds will sometimes tug on damaged feathers until they come loose. This is important since hanging feathers disrupt airflow and can get snagged. Removing them makes room for new feathers to grow in correctly aligned.
Stimulates Preen Gland
The action of preening itself helps maintain optimal function of the preen gland. As feathers push against the gland while preening, it stimulates more oil production and secretion. This ensures an adequate supply of fresh oil is available as birds continually spread it on their feathers.
Without regular mechanical stimulation from preening, the gland can become impacted and stop secreting sufficient oil. Preening provides natural gland massage to keep the oil flowing smoothly.
When Do Birds Preen?
Birds engage in preening at various times throughout the day. After waking up, preening helps smooth feathers ruffled during sleep. Birds also preen following flight or swimming to realign any displaced feathers and reapply waterproofing oils.
Birds will preen several times a day, often in short bursts. After preening, they may shuffle and stretch to further settle feathers into place. More extensive preening occurs while molting to distribute extra oil to new incoming feathers. Seasonal preening prepares feathers for changing weather conditions.
Social species may preen together as a group activity called allopreening. Here birds preen each other, providing better reach to areas like the head and neck. This social bonding strengthens flock connections.
How Do Birds Preen?
The actual preening process consists of several stages:
- Nibbling – Birds nibble along feathers, pulling them between the mandibles of their beak.
- Stroking – The beak strokes down feathers from base to tip to smooth and align.
- Rubbing – Birds rub their head and neck on the preen gland to transfer oil.
- Scratching – Feet scratch areas like the head that the beak can’t reach.
- Ruffling – Body shaking and feather raising releases any loose particles.
- Shuffling – After preening, birds shuffle and stretch to settle feathers.
The nibbling action transfers tiny amounts of oil from the preen gland to the feathers. Stroking then distributes it out evenly. Rubbing on the gland and scratching ensure thorough coverage. Finally, ruffling and shuffling remove any debris and complete feather alignment.
Why Don’t Birds Preen Their Stomach?
Most birds are physically incapable of preening the feathers on their stomach area. They lack the flexibility required to bend their neck adequately to reach. The legs and feet also cannot extend enough to scratch the stomach.
Since birds cannot self-preen their stomach, they rely on a few other adaptations. Stomach feathers naturally have lower oil content and less complex structure. They don’t require as much preening maintenance. On some species, the feathers lie flat and overlap tightly to prevent debris buildup.
Birds that live in dust or sediments will bathe frequently. Water or dust bathing dislodges particles and aligns stomach feathers. Social preeners can allopreen each other’s stomach area. Mate pairs may also preen each other’s hard-to-reach places.
Problems from Lack of Preening
When birds cannot adequately preen, it can lead to various feather and skin disorders. Issues seen when preening decreases include:
- Feather matting – Feathers stick together without sufficient oil.
- Broken feathers – Brittle, malformed feathers due to lack of alignment and oil.
- Parasite infestation – Unchecked increase of lice, mites, or fleas.
- Damaged feather tips – Tattered vane edges become frayed.
- Plumage soiling – External dirt and staining of feathers.
- Skin infection – Parasites, fungi, and bacteria proliferate.
Birds that are sick, stressed, or malnourished often reduce preening. Physical issues like arthritis can also prevent normal preening. Poor feather condition then progresses and exacerbates overall health problems.
Ways to Encourage Preening
For pet birds and rescued wild birds, here are some ways to promote healthy preening behavior:
- Provide a bird-safe water dish big enough for bathing
- Offer different water textures – misting spray, shallow tray, running faucet
- Place perches and toys appropriately for rubbing
- Ensure adequate nutrition to support preen gland function
- Supplement with omega fatty acids like flaxseed
- Exposure to natural sunlight and UV light
- Gently mist feathers with water or special preen gland sprays
- Remove sources of stress like loud noise
- Give new interesting toys to reduce boredom
If a bird shows signs of inadequate preening, consult an avian veterinarian. Underlying illness may need diagnosis and treatment to get preening back on track.
Conclusion
Preening serves many critical functions for maintaining feather health in birds. It distributes waterproofing and flexible oils, removes debris, realigns structure, and limits parasites. Birds have evolved specialized behaviors and anatomy to preen effectively. Pet and wild birds alike require proper preening to keep their plumage in top condition for survival.