Alligators, like many animals, rely on other species to help keep them clean and healthy. One of the most unique cleaning relationships in the animal kingdom is that between alligators and certain birds that pick food particles out of alligator teeth. So what kind of bird cleans alligators’ teeth?
What are the unique dental features of alligators?
Alligators have a particularly interesting set of teeth that presents unique cleaning challenges. An adult alligator has between 74-80 teeth, with up to 3,000 teeth over its lifetime. Alligator teeth are conical in shape and fit so tightly together that food particles easily get lodged between them. Unlike humans and other mammals, alligators continuously grow new teeth to replace old, worn down teeth. However, the old teeth don’t fall out until their replacements push up from below, so alligators routinely have multiple generations of teeth in their mouths at the same time.
Alligators also have a special self-sharpening mechanism. The top and bottom teeth slide by each other when an alligator’s jaw closes, so they are constantly being sharpened like a knife against a sharpening steel. This keeps the teeth dangerously sharp but also wears them down over time.
All of these dental characteristics make keeping food particles out of an alligator’s mouth a full time job. This is where the birds come in.
Cleaners of the bird world
Several different species of birds regularly visit alligators to clean their teeth. The most common alligator dental hygienists are egrets and herons. These long-legged wading birds have specialized beaks that allow them to probe deeply into alligator mouths and extract insects, fish, and meat stuck between teeth. Other birds known to clean alligators include wood storks, cattle egrets, and anhingas.
These aquatic birds seem to enjoy a mutualistic relationship with alligators. The birds get an easy meal from the morsels wedged in alligator teeth. At the same time, the alligators get their teeth cleaned of debris, preventing the buildup of rotting food that could lead to infection and other dental problems.
How do birds clean alligator teeth?
Birds that clean alligator teeth have developed a special dance to safely enter the predator’s mouth. Here are the step-by-step maneuvers:
- The bird approaches the alligator head on and starts pecking at the outside of the alligator’s jaws. This appears to be an attempt to get the alligator to open its mouth.
- Once the alligator’s mouth is open, the bird uses its long neck to reach deep inside. The bird swishes its open beak from side to side, manipulating food remains out from between alligator teeth.
- All the while, the bird vigorously flaps its wings. This seems to be a signal to the alligator that the bird is just cleaning and means no harm.
- The bird then quickly retracts its head and neck before the alligator jaws shut.
This elaborate sequence allows the bird to gain access and clean the alligator’s teeth without being perceived as prey and chomped on. The flap, flutter, and shake movements probably help convince the alligator that the bird is not worth eating.
An ancient symbiosis
The alligator-bird cleaning symbiosis has been observed in scientific studies but has actually been documented for hundreds of years. In 1681, the French artist Jacques Le Moyne de Morgues painted a scene showing herons picking leeches from alligator mouths in Florida. The 17th century English pirate William Dampier wrote about “alligator birds” that “fetch out the teeth, or any sort of filth.” And in the early 1800s, John James Audubon painted egrets cleaning alligators.
So while it may seem like an odd coupling, alligators and birds have likely been dining together and keeping each other’s mouths clean for a very long time.
Benefits for the birds
Cleaning alligator teeth provides several advantages for the birds involved:
- Food source – The bits of fish, insects, and meat stuck in alligator teeth are an easy meal for the birds.
- Dental hygiene – Hard alligator teeth likely help clean the bird’s beaks and remove debris.
- Safety – Alligators seem to allow the cleaning birds to come and go safely without threatening to eat them.
In a symbiotic relationship, both participants benefit. So beyond just getting a free teeth cleaning, what do alligators get from the birds?
Benefits for the alligators
Having birds come by for regular dental visits provides some key advantages for alligators:
- Tooth cleaning – The birds are like tiny dental hygienists, picking food particles out from between alligator teeth.
- Plaque removal – This cleaning helps prevent plaque buildup that can lead to disease.
- Parasite control – Many of the birds focus on eating parasites like leeches inside the alligator mouth.
By regularly allowing birds to clean their formidable teeth, alligators get dental care that helps them stay healthy.
Unique animal relationships
The alligator and bird dental symbiosis is one of many unique relationships between species:
| Relationship | Species 1 | Species 2 | Benefit |
|---|---|---|---|
| Cleaning | Alligator | Birds like egrets | Birds clean alligator teeth Alligators allow birds to eat food stuck in teeth |
| Transportation | Ants | Aphids | Aphids provide ants with honeydew droplets Ants carry aphids to new feeding locations |
| Defense | Acacia tree | Ants | Ants attack herbivores that try to eat tree Tree provides ants with shelter and food |
| Pollination | Flowering plants | Butterflies, bees, etc. | Insects gather pollen and nectar from flowers Pollen gets transferred, allowing plant reproduction |
In each relationship, both species provide a service that benefits the other species. This kind of mutually beneficial symbiosis is surprisingly common in the natural world.
The specialized egret beak
Egrets and herons have special beak adaptations that make them expert alligator dentists:
- Long, narrow beak – Allows the bird to reach deep between teeth
- Pointed tip – Enables digging out stuck food particles
- Serrated edges – Grip food remains
- Curved upper mandible – Hooks under food debris
Other birds could not so effectively clean alligator teeth. Woodpeckers, for example, have strong beaks for hammering and drilling wood, but lack the hooked shape needed to extract debris.
The egret beak shows how evolution has specially adapted some bird species for their unusual role as alligator dentists.
Alligator dental dangers
Despite their alliance, alligators pose several dangers to the birds that clean their teeth:
- Bite injuries – Alligators have extremely strong bite forces. One wrong nip could crush a bird’s delicate body.
- Drowning – Alligators typically allow birds to clean their teeth while partially submerged in water. A bird could be accidentally pulled underwater.
- Rotting food – The bits of rotten food extracted from alligator teeth could make a bird sick if swallowed.
Yet the birds seem to have adapted ways to minimize these risks. The elaborate signaling ritual with wing flapping appears to prevent most bite injuries. The birds also avoid putting their feathers in the water, reducing drowning risk. And they may have strong stomach acids to neutralize harmful bacteria from rotten debris.
The fact that birds continue to clean alligator teeth suggests the rewards outweigh the risks for these unusual dental hygienists.
Other alligator cleaners
Besides birds, some fish species also appear to clean alligators:
- Bluegill sunfish – Feed on parasites attached to alligator skin
- Suckermouth catfish – Extract food particles from between alligator teeth
- Coelacanths – Clean dead skin cells from alligator bodies
The fish benefit by getting easy access to food sources. The alligators get dental services and overall body cleanings. It’s a win-win situation for both parties.
Alligator etiquette for bird dentists
To safely enjoy a cleaning session, alligators should:
- Open mouth wide when birds approach – This invites the birds to enter and clean.
- Remain still during cleaning – Avoid sudden movements that could frighten or injure the birds.
- Close mouth gently – When closing jaws, do it slowly to avoid trapping birds inside.
- Let birds finish before fully closing jaws – Give birds time to remove their entire head before completely shutting mouth.
By following these tips, alligators of all sizes can continue to benefit from regular dental cleanings by their bird partners.
The odd bird-gator alliance
While it may seem bizarre, the partnership between alligators and birds that clean their teeth makes perfect sense biologically:
- Alligators need debris cleaned from their specialized teeth
- Certain bird beaks can effectively remove the debris
- The birds get an easy meal from their efforts
- Both species benefit from the interaction
Nature has many surprising examples of symbiotic relationships. The alligator dental cleaning association is one of the most fascinating – and successful.
Conclusion
The alligator dental cleaning relationship reveals some ingenious solutions that emerge from natural selection. Alligators develop ways to avoid chomping their helpful bird partners. The birds evolve beak shapes perfectly designed to scour alligator teeth. Each species adapts in ways that allow the symbiosis to persist.
This cleaning alliance provides yet another example of the amazing connections within the natural world. Alligators get dental hygiene. Birds get easy access to food. And together, they demonstrate nature’s power to forge innovative partnerships that span the animal kingdom.
