One of the most remarkable actions of turtles are tortoises is their ability to retract into their shells. However, not all turtles can hide all of their body parts under their big backbone. Sea turtles are one of them: they cannot hide in their shells.
So what does this mean for sea turtles?
How “Hiding” Works
Turtles were long believed to hide in their shells as a form of protection. However, scientists recently began to believe that turtles retracting the head and neck into their shells evolved as an efficient way to hunt for food (as more distance to move means greater momentum), not as a form of protection.
There are two types of turtles with two different ways of hiding in their shells.
The first type is pleurodires, which pull their heads and necks into their head in a sideways position. The second type is cryptodires, which pull their heads and necks back straight. Pleurodires evolved first.
Most turtles and tortoises have very flexible necks and limbs that can easily retract on command. Some even have something called a plastron, which closes shut so that the turtle is completely safe from the outside world if it so chooses.
Why Can’t Sea Turtles Hide?
It seems kind of unfair that so many turtles and tortoises can retract their head and limbs into their shells and sea turtles can’t. Yet, sea turtles have an advantage that allows them to be able to ditch the shells for something even better.
Most turtles and tortoises have very bulky shells and, therefore, move pretty slowly. Seas turtles, on the other hand, have smaller, flatter shells that help them move quickly. Sea turtles have also evolved flipper-like feet to move quickly and elegantly through the water.
So, sea turtles may not be the most equipped to defend themselves from threats and predators as other turtles and tortoises, but they have evolved to be speedy and agile to make up for it!
Dangers of Not Hiding
Although the sea turtle has an advantage to not being able to hide in its shell, it doesn’t mean that there aren’t any dangers involved.
Because sea turtles can’t retract their head, neck, and limbs into their body when they are scared, they are much more vulnerable to predators if they can’t swim away fast enough. This is especially true when these turtles are on land, as sea turtles may move fast in the water but have trouble getting away from predators above the surface.
Additionally, because so few people know that sea turtles can’t retract their limbs into their shells, they mistake a sea turtle not hiding for being accepting of human interactions. We encourage all readers to not physically engage with sea turtles if you see them on land: just because they’re not hiding as most turtles do does not mean they’re not scared of you.
In addition to not being able to hide from predators and humans, not being able to retract their limbs also makes sea turtles more susceptible to becoming entangled in marine debris or fishing nets. Unfortunately, entanglement makes sea turtles even more vulnerable to predators if they don’t drown first.
What You Can Do
Now that you know sea turtles can’t hide in their shells, there are a few steps you can take to help them feel safer!
If you see a sea turtle on land (or in the water!) please do not approach it or try and touch it. While they are truly magnificent creatures, they can be pretty scared of tall two-legged beings hobbling towards them after they wake up from a nap on the beach, and they won’t be able to hide to warn you they are uncomfortable.
Second, be conscious of your trash, especially if you are living or staying by the ocean. Sea turtles are more susceptible to becoming entangled in marine trash because they can’t retract their limbs like other turtles.
Lastly, if you see something, say something! If you are boating and find an abandoned fishing net, make sure you contact someone who can take care of it before a sea turtle becomes stuck in it. If you see a sea turtle tangled, do your best to set it free without scaring it.
Sea turtles are not “normal” turtles in that they don’t retract or hide in their shells when they feel in danger. While they have adapted to evolve other ways of staying safe (such as being able to swim fast!) humans can still do their part to ensure these turtles don’t feel threatened.