Turtles do not have ears that you can see, but this does not mean they do not have them. Instead, turtles have internal ears that are hidden from view. They are almost impossible to notice without close inspection and adequate training.
Turtles can still hear what is going on around them. Their internal ear bones are covered with a layer of skin that sound can permeate. This helps to protect them from predators and assists in hunting prey.
The skin flaps covering the bones vibrate and send low-frequency sound waves down the turtle’s ear canal. This allows them to hear, although to a much lesser extent. They primarily hear lower frequency sounds and use the displacement of air to detect movement.
This skin is known as the cutaneous plate. It is formed of a circle of scales that are smaller than the ones covering the rest of the turtles’ heads. Underneath these scales is a subcutaneous layer of fat. This is why turtles cannot hear well on land, but sound wave conduction is improved underwater.
It is believed that all turtles were originally aquatic. This is because the structure of sea turtles’ ears is the same as that of land turtles. The water serves as a conductor, transporting and amplifying low-frequency sound waves. This means that sea turtles have slightly improved hearing compared to their land-dwelling counterparts.
The skin flaps covering the bones are much more suited to ocean-dwelling life. This is because it would serve to keep the water out of the head, something not required on land. The skin vibrations underwater help the sea turtles to notice changes in water pressure as other animals come close.
These are located behind the flap of the skin. They have middle ear bones that are used to send vibrations down the ear canal. In their inner ear, you will find smaller bones. These are to detect more specific changes in vibration and sound.
The inner ear then transports these sound waves to the hearing center of the turtle’s brain. This is very small in turtles as hearing is seen as a less important sense.
So can turtles hear?
Until almost 2014, it was believed that turtles were mostly deaf. This was largely due to the location of their ears meaning that many sounds would be blocked out.
According to some studies, it is estimated that sea turtles hear frequencies from 200 to 750 Hz at best. They cannot really hear sounds pitched above 1,000 Hz.
Green sea turtles hear frequencies ranging from 200 to 500 Hz at best. In comparison, humans can hear frequencies from 20 to 20,000 Hz.
What do turtles use sound for?
They emit low-frequency sound waves to help them navigate and communicate with one another.
Many baby sea turtles have been observed to emit these sounds. This is to attract adult female sea turtles who will then care for and protect the babies.
How do turtles communicate?
Turtles communicate mainly through sound. During the mating process, male Travancore turtles are known to emit a high-pitched whine.
Some larger-headed species of freshwater turtles make a loud roaring sound to scare away predators when they are pulled from the water. Arrau turtles, that live in the Amazon River, are believed to use echolocation to move around.
A host of studies conducted by herpetologists prove that female turtles speak to their hatchlings while they are still in their shells. These noises are believed to indicate to the babies that it is time to hatch. This means that they will all hatch at once and it is less likely stragglers will be picked off.
Once hatched, the females make noises that call out to their newborns. This prompts the babies to travel toward the adults, meaning that they all come together in one group. The larger group then migrates en masse to the better-equipped areas of the river.
Turtles also communicate largely through touch and many courtship rituals involve dancing. If you can see a lot of their extremities, this is a good indication that they trust you.
Also read: What sounds does a turtle make?
What other senses do turtles have?
To make up for their poor sense of hearing, turtles’ other senses are vastly improved.
The turtles’ senses of smell and sight are much stronger than their hearing. As far as we understand, turtles can see shapes, patterns, and colors. They can see near-ultraviolet, yellow, violet, and blue-green light.
Sea turtles have slightly improved vision underwater than on land. We do not believe that turtles have any peripheral vision.
Turtles naturally have a strong sense of smell. This is because they have evolved to keep themselves safe, find one another, and hunt for food. This sense is effective both on land and on water.
Turtles do not smell in the same way as we do. They have lumps underneath their chin known as barbels. These contain nerves that can distinguish between smells and even pick up on female pheromones. Some theorize that smell is used to return to the same beaches to mate and lay eggs every year.
Turtles have sensitive skin, despite their leathery and thick appearance. They can even feel touch through their shells!
Not all turtles have a sense of taste. Some do have taste buds, such as sea turtles. Snapping turtles do not, which is speculated to assist them in eating poisonous animals.
Turtles and Ear Infections
Rarely do we notice ear infections in sea turtles. They are more commonly seen in freshwater and box turtles.
Turtles can develop middle ear infections. If this does not get treated in time, the area becomes filled with pus. This then dries out and becomes hard. The pus then fills and blocks the ear cavity in what is known as an aural abscess.
A visual indication of this kind of infection is a lump on the side of the turtle’s head. If it is not treated correctly the infection can rapidly spread around the head area. The head can become so swollen that the surface layer ruptures.
What causes ear infections in turtles?
Ear infections are commonly a consequence of a weakened immune system.
This tends to be a result of malnutrition or an inadequate diet. It can also be caused by an unclean environment.
How to Prevent Ear Infections in Turtles
One of the best preventative measures to take is to supplement your turtle’s food. We recommend Vitamin D and calcium supplements, as well as Vitamin A. Many commercial turtle foods will contain near-perfect levels of Vitamin A for turtle health.
You should always use an aquarium filter to keep the water clean. This is not a replacement for cleaning the water, and you should make sure to change the water regularly. This prevents bacteria from the turtles’ feces from building up in the water that the turtle will be drinking.
When changing the water, you should also scrub out the inside of your tank. We suggest making a schedule and cleaning according to that. This will ensure it is done at regular intervals and it is never left uncleaned for too long.
Be aware of how your turtle is acting in its tank. An ear infection could also be caused as a result of damage to the ear membrane. If they regularly crash into objects in the aquarium or fight with a tank mate this could be a result. If you notice any aggression, please take steps to separate out the animals.
What are the symptoms of an ear infection?
The most obvious symptom of an ear infection in a turtle is a bulge where their ear flaps are located. This indicates a build-up of pus underneath the scales as a result of an infection. In severe cases, you may even be able to see this pus through the membrane of the ear.
If your turtle seems reluctant to eat, in pain when opening its mouth, or is having difficulty swallowing it is a good idea to get them checked out by a veterinarian. An inflammation of the eye, scratching at their ears, or rubbing their heads on things are also usually indications of an oral abscess.
If anything seems different with your turtle we would strongly advise getting them looked over by a qualified veterinarian. They will perform a physical examination of the mouth and take some blood from your turtle. They will also discuss with you the turtle’s diet and living conditions.
How are ear infections in turtles treated?
Your turtle is likely to need some kind of surgery to fix its issues. This will remove the pus and debris that has collected underneath the ear membrane.
The veterinarian will anesthetize the turtle and make a small incision in the ear membrane to provide access to the inner ear. They will then gently pull the pus plug out and flush the ear cavity with a saline solution.
If the infection is severe, an antimicrobial solution may also be flushed through. Once this is done, the veterinarian will fill the cavity with an antibiotic ointment.
You will need to clean and reapply the ointment every day. It is likely your turtle will also be issued with an injectable or oral antibiotic as well.
The healing process is likely to take a few weeks, during which time the turtle’s living environment must be adapted. It needs to be safe and comfortable, warm and humid. The tank should be cleaned every day and the bedding replaced daily too.
If you have an aquatic turtle, ask your veterinarian for specific advice on how best to support them during the healing process.