Preening is a common behavior seen in birds where they use their beak to groom, clean, and maintain their feathers. It serves several important functions for a bird’s health and wellbeing. When a bird preens, it is doing some necessary “self-care” to ensure its feathers stay in prime condition for body temperature regulation, flight, communication and display. Understanding the meaning behind preening in birds provides insight into their biology and behavior.
What is preening?
Preening refers to how a bird uses its beak to tend to its feathers. It involves nibbling, grooming, wiping, scratching and spreading oils over the feathers to keep them supple and aligned.
Birds have a preen gland or uropygial gland near the base of their tail which produces an oily substance. As they preen, they extract this oil and distribute it throughout their feathers. This helps mat and assemble the tiny hooks which link the barbs of feathers together. It also helps realign any feathers that are out of place.
In addition to distributing preen oil, preening allows birds to:
- Remove dirt, parasites and old feather particles
- Dry feathers after bathing
- Recondition feathers and maintain flexibility
- Straighten barbs and reassemble the microstructure of feathers
When a bird runs its beak along its feathers and gently bites at them, it is meticulously caring for its plumage. The placement of the beak when preening matches how the feathers lie over the body, allowing meticulous adjustments.
Why do birds preen?
Birds preen for the following reasons:
Feather maintenance
Preening maintains feathers in top condition. Feathers are complex structures composed of keratin. They are lightweight yet provide insulation and allow flight. Their integrity requires maintenance to upkeep.
Preening removes old keratin, dust, dirt and parasites. It realigns feather barbs and reconditions the microstructure. This preserves the feather’s shape, flexibility and aerodynamics. Proper feather care impacts factors like body temperature, ease of flight, mating displays and communication.
Application of preen oil
Distributing preen oil from the uropygial gland waterproofs and suppresses microbial growth on feathers. The oil contains antibacterial and antifungal properties. Keeping feathers flexible and separating the tiny hooks allows for proper insulation.
Signaling health
Frequent thorough preening signals a healthy active bird. When ill or stressed, preening decreases. Disorderly plumage can be a warning sign something is wrong.
Social bonding
Social preening between mated pairs or families strengthens bonds. It signals trust, affection and teamwork in maintaining plumage that cannot be easily reached alone.
When do birds preen?
Birds preen most actively at the following times:
Morning
Birds straighten out feathers rumpled in sleep and apply fresh preen oil after nighttime inactivity.
After bathing
Preening rearranges feathers and restores water resistance after becoming wet.
Before and after flight
Ensuring feathers are orderly improves flight performance and aerodynamics.
When stressed
Increased preening can signal anxiety. It is a displacement behavior when a bird is nervous or faced with conflict.
During mating season
Thorough preening ensures birds look their best for courtship, territorial displays and mating. Bright colorful plumage and well-kept feathers are signals of fitness.
How often do birds preen?
Most birds preen daily, especially in mornings and evenings. Small birds may preen several times an hour. Larger birds like swans may only need to preen extensively every few days. Birds with thicker plumage preen more frequently than sleeker birds.
During molting seasons, preening increases to help condition new incoming feathers. When raising chicks, parent birds preen constantly to maintain feathers while incubating eggs and sheltering the nest.
In general, expect preening sessions:
- 5-20 times per day for small songbirds
- 12-50 times per day for medium sized birds like crows
- 2-12 times per day for larger waterfowl and raptors
What does preening look like?
Preening varies across bird species but generally involves similar behaviors:
Neck curvature
Birds often curve their necks around to nibble feathers over their back, wings and belly. This allows them to systematically preen hard-to-reach areas.
Rubbing
The beak slides along the feather shaft from base to tip to smooth the barbs.
Nibbling
Gentle nibbles with the tomium (cutting edge of the beak) realigns hooks and barbules.
Scratching
Scraping with claws dislodges debris and parasites on skin beneath feathers.
Wiping
Brushing feathers with the beak distributes oils down the vane.
Fluffing
Shaking and feather ruffling spreads oils and resets feathers.
| Preening behavior | Description |
|---|---|
| Neck curvature | Curving neck allows bird to reach all feather areas |
| Rubbing | Sliding beak smooths feather barbs |
| Nibbling | Gently bites realign feather hooks |
| Scratching | Scrapes skin to remove debris |
| Wiping | Beak distributes oils down feather vane |
| Fluffing | Shaking and ruffling spreads oils and resets feathers |
Preening positions
To reach all their feathers, birds contort into various positioning while preening:
- Winged-lifting: Lifting one wing at a time to preen the underwing and body.
- Leg-lifting: Lifting one foot to preen the leg, belly and underwing.
- Wing-drooping: Drooping a wing down to reach the back and rump.
- Over-the-shoulder: Reaching over far enough to nibble back feathers.
- Head-to-tail: Contorting to nibble preen gland area and tail feathers.
Birds seem remarkably flexible thanks to their special preening postures. Watching their moves allows you to see how their anatomy uniquely adapts them for feather maintenance.
Difference between preening and scratching
Preening and scratching serve different functions:
Preening involves using the beak to tend to feathers. The bird methodically cares for plumage piece by piece.
Scratching uses the feet and claws to relieve an itch or dislodge debris on skin beneath feathers. It provides relief through rubbing, not feather care.
Key differences
| Preening | Scratching |
|---|---|
| Uses beak | Uses claws |
| Systematic feather care | Relieves itches |
| Focuses on feathers | Targets skin under feathers |
While both involve grooming motions, the intent differs between preening and scratching. Preening maintains feathers while scratching provides relief to skin.
Unique preening adaptations
Certain birds have specialized preening adaptations:
Raptors
Raptors have bony comb-like serrations on their beak called a tomial tooth. This allows them to preen and straighten feathers more effectively.
Water birds
Birds like ducks have more preen glands to protect their feathers from waterlogging.
Long necked birds
Birds like flamingos have extra flexibility in their vertebrae to allow extreme neck bending for hard-to-reach preening.
Parrots
Parrots use their dexterous tongues to spread oil during preening. The tongue provides an extra preening tool.
Waders
Wading birds have long legs perfect for lifting up during preening. This allows them to carefully align feathers on otherwise hard-to-reach areas.
Social preening behaviors
While preening is an individual activity, some special social preening behaviors exist:
Mate preening strengthens the bond between breeding pairs. Partners preen each other’s head and neck areas that are difficult to reach alone.
Family preening helps parent birds and chicks. Parents preen chicks to remove parasites and condition fledgling feathers. Chicks preen parents in a display of feeding solicitation.
Allopreening is when unrelated birds in a flock preen each other. It signals community membership. Certain birds like parrots often allopreen frequently.
Courtship preening helps potential mates assess each other. Watching a potential partner’s preening skills helps judge their health and fitness.
Preening problems
Certain preening abnormalities can signal underlying issues:
Excessive preening
Constant preening beyond needed feather maintenance can indicate stress, anxiety, parasites or skin infections. It becomes an obsessive displacement behavior.
Feather plucking
Damaging preening that pulls out feathers is abnormal. It can result from poor diet, lack of stimulation, or compulsive behavior.
Incomplete preening
When sick or weak, birds often stop fully preening. Resulting unkempt plumage signals health issues.
Difficulty preening
Injuries, arthritis, or aging can make preening physically difficult. Lack of flexibility prevents proper feather care.
Preening across bird groups
Preening habits vary somewhat between bird groups:
Songbirds
Frequent, short preening sessions with fluffed feathers. Thorough body coverage.
Birds of prey
Long intense preening focused on realigning specialized flight feathers.
Waterfowl
Oil application is crucial. Use water to preen and bathe communally.
Game birds
Fast meticulous preening to camouflage scent from predators. Minimal oil used.
Parrots
Social activity with mate assisting. Use tongue and foot to scratch.
The importance of preening
While it may seem like just grooming behavior, preening serves vital functions:
- Maintains feather structure needed for critical functions like flight, temperature regulation, communication, and courtship displays.
- Cleans feathers and controls parasites that can harm bird health.
- Spreads antimicrobial preen oil and waterproofs feathers.
- Indicates health status based on preening completeness.
- Provides social bonding opportunities between mates and families.
Proper preening benefits bird fitness and survival. Understanding this common bird behavior provides insight into avian biology, health and habits.
Conclusion
Preening is an essential maintenance behavior where birds use their beak to tend to their feathers. This grooming serves critical functions like feather care, parasite removal, oil distribution, and social bonding.
The techniques, frequency, and extent of preening provide information on a bird’s health and comfort. Adaptations allow different bird groups to effectively preen based on their unique structures and lifestyles.
Observing preening habits and positions reveals the anatomical tools birds naturally possess for this vital feather upkeep. So next time you notice a bird contorting to nibble its feathers, realize it is diligently engaging in necessary self-care.
