Can Turtles See in the Dark?

Turtles share a lot of similarities with humans, but they also have a few key differences, and sometimes it’s hard to know exactly how they differ from us. In today’s guide, we’re going to take a look at whether or not turtles can see in the dark.

Yes, turtles can see in the dark but not how you expect it too. They do not have night visison to see clearly like most people think. They see things in reddish colour at night.

Turtles and Night Vision

When people say “see in the dark,” there are a few things that they can mean by it. Most people would assume that this phrase means that the animal can see as clearly in the dark as it can see in the light (AKA night vision).

Animals that have night vision include cockroaches, dung beetles, and owls, but not turtles. In fact, turtles have very similar eyes to people when it comes to the amount of light that they can perceive.

What this means is that turtles can see in the dark just as easily as you can, and people can see in the dark surprisingly well. Always being surrounded by electric lights, it’s easy to forget how well human beings can see in the dark.

If you want to figure out how well you can see in the dark, turn your lights off and stand in the room for a few minutes.

As your pupils dilate, you’ll begin to see more of your surroundings until you can see much better than you previously could. Vision in the dark becomes better when a turtle’s pupils are dilated because the pupil physically opens up wider and allows more light to filter into the retina.

Keep in mind that you’ll still need a small amount of ambient light filtering into the room, as our eyes (and turtles’) can’t perceive anything if there’s absolutely no light to be seen.

Do Turtles See Differently in the Dark than Humans?

While turtles can see just as easily in the dark as you and I can, they don’t see exactly the same things.

When turtles look around in the dark, they’ll notice that everything has a much redder hue than it would to a human. This is because they have a gene known as Tapetum lucidum in their eyes, making everything redder, whether it’s in the light or darkness.

What’s interesting is that Tapetum lucidum is also responsible for night vision in other animals’ eyes, but it’s not present in high enough concentrations in turtle eyes to allow for vision in the dark.

How to Confirm that Turtles Don’t Have Night Vision

If you don’t believe that your turtle can’t see in the dark, you can perform a simple test to determine it for yourself, and it has to do with Tapetum lucidum. Since Tapetum lucidum is a reflective layer of tissue located behind the retina, it will be visible in photographs.

Before taking a picture of your turtle, make sure that the flash is on. If an animal were to have enough of this layer to let it see in the dark, it would be visible in a photograph. When you snap a picture of your amphibian friend, you’ll notice that there is no light reflecting back from its eyes.

This is the easiest method that you can use to deduce whether or not your turtle has night vision.

Why Does My Turtle Stay Awake at Night?

Most people come to the conclusion that turtles can see in the dark when they notice them roaming around at night and sleeping during the day.

This is because turtles are nocturnal creatures, meaning that they spend most of their time awake during the night. Turtles have evolved to stay awake mainly at night because they are vulnerable prey animals, and this is the same reason that they’ve evolved to carry around a durable shell on their backs.

Roaming around at night instead of the daytime makes a turtle much less vulnerable to the predators that are typically hunting for them earlier on. Most predators choose to hunt during the day because their prey will be much more visible, making them easier targets.

Since your turtle is unlikely to forget generations of biological programming easily, you may notice it being a lot more energetic during the hours when you’re asleep. While a turtle can’t see much better at night than you can, it likely feels a lot more comfortable spending its waking hours when the sun’s down.

Should I Keep My Turtle’s Aquarium Lights On at Night?

Since turtles spend so much time awake at night, some owners wonder whether they should keep their turtle’s aquarium lights on during the night so that their pet can see better.

Unfortunately, this is often a bad decision as it will prevent your turtle from getting used to your schedule and will only accentuate its nocturnal habits. Despite their instincts, turtles are pretty good at adapting, and sooner or later, your turtle will get used to your schedule and spend more time awake in the day.

When you leave the aquarium lights on for your turtle, you’ll end up disrupting its delicately balanced sleep schedule, and you may even cause it to develop a sleep disorder.

While turtles may be nocturnal creatures, this doesn’t mean that they never sleep at night, and your turtle may end up growing fatigued or stressed if you leave its aquarium lights on all the time.

Remember that turtles are much smaller than us, so they perceive small lights like their aquarium lights to be much brighter than we do. For a human, being in an aquarium with lights that never go off would be like living in a world where the sun never goes down.

Conclusion

To summarize, turtles are nocturnal creatures that can see in the dark just as well as people can, but this doesn’t mean that they have night vision, so they can’t see in the dark.

Try not to change your habits too much now that you know turtles are nocturnal. Doing something like leaving your aquarium lights on can damage your turtle’s health, both mental and physical.

Sources

https://blogs.scientificamerican.com/thoughtful-animal/the-turtle-with-human-eyes/

https://link.springer.com/chapter/10.1007/978-3-642-66468-7_8

https://northernwoodlands.org/outside_story/article/night-vision-how-animals-see

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