Yes, tortoises have ears, and they can hear quite well. But how good is their hearing ability, how does it work, and do they have other senses they can use when hunting, looking for plants, or evading predators?
Let’s discuss that!
Anatomy of Tortoise Ears
Tortoises don’t have external ears, which is a normal feature among reptiles. The ear itself is internal and looks like a small depression behind the eyes.
It may be difficult to locate due to the scales and the layer of skin covering it. These protective layers are meant to prevent debris from getting in.
The tortoise’s ear comprises several components, such as the eardrum and the ossicles, which are tiny bones that vibrate and transmit sound further into the nervous system.
Then there’s the cochlea, that’s capable of converting the vibrations into electrical signals that the nervous system can decipher.
The tortoise’s hearing ability is rather sharp, but not as sharp as that of other animals. The tortoise needs just enough to get by and detect predators in time.
It doesn’t need it to find food because most tortoises are herbivorous, and plants don’t typically make noise.
Ear Function and Hearing Ability
The function is pretty much self-explanatory, but what about the hearing ability itself? Tortoises can detect sounds between 10 and 182 Hz, so they can get lower than humans, which can only get to 20 Hz, but not as high as humans cap at 20,000 Hz.
Tortoises can hear low-frequency sounds just fine but aren’t equipped for high-pitched noises. Fortunately, they don’t need to be. Tortoises don’t rely as much on their sound to outsmart predators.
That’s because, even if they could hear the predators from afar, they still wouldn’t have time to flee the scene; fleeing isn’t exactly what tortoises do best, given that they can only reach 1-4 mph on land.
Instead, tortoises rely on their shell and camouflage for protection. This is typically enough to keep adult individuals alive since the larger the tortoise is, the fewer the predators willing and capable of eating it.
Types of Sounds Tortoises are Able to Hear
Tortoises can actually hear an impressive range of sounds, such as:
- Growls, rumbles, and grunts coming from other animals, especially predators
- The distinct sound of footsteps, whether from humans or other animals
- Ground vibrations caused by large animals, vehicles, or even smaller creatures
- Rustling of leaves caused by other animals and even insects
- Sounds of waves splashing nearby
- The distinct calls and chirps of other tortoises during the mating phase or territorial struggles
- The sound of animals foraging in their vicinity
- The wind blowing through the foliage or the trees around them
- The distinct low-frequency sounds associated with thunderstorms and other weather phenomena
- Various environmental sounds like branches creaking, mild water movement, rustling leaves, etc.
In general, tortoises have their hearing primed for detecting potential food sources and water.
The ability to detect the sound of splashing water nearby is critical to the tortoise’s survival, which is why hatchlings prioritize it above anything else.
How do Tortoises Respond to Sounds?
The tortoise will respond to different sounds according to its biological programming.
Here are some potential responses, depending on the type of sound:
- Orientation – This is typically the first response. The tortoise will rotate the head or the entire body in the direction of the sound. This allows for better spatial localization so that the reptile can learn the type of sound, intensity, and proximity.
- Communication – If the sound comes from another tortoise of the same species and the animal recognizes it, it may reply in kind. Tortoises are known to produce a wide range of vocalizations to communicate intentions like “Stay away,” “You’re trespassing,” “Wanna go out?” etc.
- Alertness – Tortoises may enhance their attention if the sound they’re detecting is on the danger list. In that case, that tortoise may even retreat into its shell and lay motionless if the sound source is too close for comfort.
- Run – Using the notion of running is overkill, given that tortoises aren’t quite adept at running. But they can leave the area if they detect a threat nearby and want nothing to do with it.
Significance of Hearing for Tortoises
Sound detection plays 3 critical roles in a tortoise’s life:
- Finding sustenance – Tortoises can detect the movement of nature around them so that they can learn where they might find food and water. The ability to decipher the world around them through sound is critical for their survival.
- Predator detection – All animals have the ultimate purpose of remaining alive for as long as possible, and tortoises are no different. Their ability to detect the movement of potential predators around them is invaluable in this sense.
- Mating purposes – Tortoises need to find each other for breeding purposes, and the ability to produce, detect, and decipher mating sounds is greatly appreciated.
Other Senses of Tortoises
Tortoises only rely on sound moderately, but they have several other senses that they use to navigate their ecosystem.
- Vision – The tortoises’ vision ability is above decent. They can identify a wide range of colors, textures, and movements, which allows them to distinguish between predators, food, and harmless animals.
- Touch – Tortoises may seem clunky, but they’re actually quite sensitive in terms of touch perception. Their tactile senses allow them to navigate their environment better and with greater precision to evade dangers and find food and water.
- Smell – The smell is another good tool for assessing the surrounding habitat in search of food and other tortoises. This sense is particularly important during the mating season when tortoises can sense the pheromones emitted by their potential mates.
- Taste – Taste is among the most important senses because it works in conjunction with smell to differentiate between food and everything else.
Each sense plays an important role in the tortoise’s physiological functioning, and there’s not one more important than another.
Tortoises have decent hearing, but their survival doesn’t depend on their ability to hear necessarily.
This explains why tortoises don’t have the best hearing when compared to other animals.