How Wild Tortoises Hibernate According to Science - TortoiseOwner.com

How Wild Tortoises Hibernate (According to Science)

Many reptile owners have mini panic attacks when it comes to the subject of hibernation. It’s not a rare reaction, especially since humans don’t hibernate and the whole process seems a bit bizarre to us. But don’t be worried; we’re here to shed some light on this mystery. By understanding how wild tortoises hibernate, you can be sure you’re helping your pet tortoise get the best sleep ever.

What is hibernation?

Let’s get the technical stuff out of the way first. Hibernation is basically a long, deep sleep to help an animal survive harsh winter conditions. It’s not a traditional sleep where brain activity, digestion, and other bodily functions keep going. It’s a period of torpor, which is inactivity in both body and mind.

The body keeps functioning in a hibernating animal but at incredibly slow rates. This reserves energy and sustains the animal until conditions outside the hibernation area are more suitable for life.

Hibernation is Different for Tortoises

Hibernation for tortoises isn’t the same as other animals, such as bears. For tortoises and other reptiles, it’s actually called brumation. It’s the same basic concept, of course, but there are some important distinctions for tortoises. This is where inexperienced tortoise owners can end up causing the death of their little buddies instead of helping them have a good sleep.

Getting Fat

First, tortoises don’t really fatten up before hibernation, at least not how you might be imagining. Everyone has seen the images of wild bears chowing down on everything in sight right before they take their long winter’s sleep. They pack on pounds and pounds of fat and grow thick, warm coats.

Yes, tortoises also need to build up some fat and energy reserves for hibernation, but not to the same extent that mammals would. If they ate that much, they’d become obese and they could possibly die during hibernation due to the health issues that accompany obesity.

Besides, in brumation, digestion slows down to a crawl. During brumation, the digestive tract cannot reach optimal temperatures, therefore it can’t move as quickly as it does the rest of the year. This conserves energy and keeps the tortoise slow and sleepy.

Adding extra fat to a body that’s not going to be burning calories or working at optimal efficiency is simply wasteful. Mother Nature is never wasteful!

Extended Prep Time

Their prep period is also much longer than that of a bear, for example. Tortoises begin prepping for hibernation when temperatures begin to drop, but well before it’s too cold to move about. Remember, they’re cold-blooded, so they need warmth to be active!

Being cold-blooded also means they’re much more sensitive to temperature fluctuations than mammals are. Tortoises can sense when autumn is coming before the leaves start to change and mammals feel any chill in the air.

Not for Every Tort

Tortoises and turtles differ from other hibernating creatures in another way. Not every species will need to hibernate. In fact, some species can’t do it at all. If you force a non-hibernating species to hibernate, it will die.

Two Kinds of Hibernation… Kind of

It’s incredibly important to understand that there are two kinds of hibernation for tortoises. Kind of. There is the standard hibernation, which we are covering in detail here. But there is also a special kind of hibernation called aestivation.

When a tortoise goes into aestivation, it’s not because it’s time for a good, solid, lengthy nap. Aestivation is triggered by conditions that are too hot or dry to keep a tortoise healthy. There may be a drought where water is scarce and food is scarcer, for example. In these cases, the tortoise will dig deep underground and stay in a cool, moist burrow until outside conditions are better.

This is an amazing survival adaptation that wild tortoises have developed over millions of years. For the captive tortoise, however, this should not be a regular part of her life. Aestivation is triggered by unhealthy and sometimes downright dangerous conditions. If your captive tortoise is showing signs of aestivation, you need to remedy the problems in her environment immediately!

They May Not Stay Asleep

Perhaps the most interesting behavior in brumating tortoises is the fact they might not stay asleep the whole time. Unlike mammals, which must remain asleep the entire time, tortoises can wake up and even leave their hibernation area for short amounts of time.

Not every tortoise will do this, of course, but many will wake up on particularly warm winter days to get a drink, catch some sun, and maybe find a snack. They won’t be as active as they are in warmer months, but you may see one trudging along at a snail’s pace.

Tortoise hibernation in the wild

Since not every tortoise species will hibernate, we’re only talking about the hibernating species in this article. Please check to be sure your tortoise is a hibernating species before applying any of this knowledge to your tortoise-keeping duties.

Climate Factors

Since tortoises hibernate to make it through cold and harsh months, it stands to reason that tortoises in hotter climates are less likely to hibernate. This is not always the case, but it’s important to note that the overall climate has great bearing on whether a tort will take that long nap or not.

However, even desert and tropical species can hibernate. Species requirements are just as important as outside factors, such as weather and temperature. In milder winters, a hibernating species may still go to sleep, even if it’s not too cold for them to be out and about.

Oddly, sometimes it’s even individual preference for wild torts. Tortoises are pretty cool like that. They can decide for themselves if they want to hibernate during a mild winter or not. While this isn’t seen across the board, there have been rare tortoise sightings in the wild during normal hibernating times.

Of course, as mentioned above, on warm winter days, sometimes a tortoise simply woke up and came out for a drink. It’s best not to interfere either way.

Age Factors

There is an ongoing argument in the reptile-keeping world over tortoise age and hibernation. Some believe that young captive torts should never be hibernated. Others have pointed out that wild torts naturally hibernate from birth onward. It is what they evolved to do, so humans should not interfere.

We fall somewhere in the middle on this site. There is a lot more than just age to consider when talking about hibernation. But since we’re focusing on wild tortoises in this article, we’ll leave the details of that discussion for another time.

For wild tortoises, age isn’t usually a factor at all. Hibernating species are born with the innate knowledge of hibernation and will go about their business on their own.

Health Factors

In captivity, it’s easy to see when a tort isn’t feeling well. We can step in and help them get better before hibernation starts. Sadly, for wild tortoises, there is no help when things go sideways. A sickly tortoise may dig in for hibernation but not get back up when the weather warms up.

However, since bodily functions slow down and body temperature lowers, some sickly tortoises can actually make it through hibernation. They’ll be weaker and slower than their healthier cousins, but making it through the cold winter safely is a good step in the right direction. With warmer weather comes better food, more water, and more warmth. Sometimes, that’s all a sick tort needs to feel better.

All that said, you should never interfere with a sickly wild tortoise. We know it’s difficult to just walk away from a tiny tank in need, but wild torts are surprisingly sensitive creatures. Leave them alone. If you must intervene, contact wildlife officials and let them know of the sick fella. Human intervention with wild tortoises ends up in tragedy, more often than not.

A Word on Relocation

Tortoises in the wild have adapted to their specific environments and their specific breeds. That means if a tortoise from one area is relocated to another with vastly different environmental factors, the relocated tortoise may not survive when it comes time to hibernate. This is one reason you should never relocate a tortoise on your own—call wildlife authorities to handle any situations that may require relocation.

How do wild tortoises prepare for hibernation?

Wild tortoises must prepare for hibernation the moment the weather starts to cool off. They have to be ready for the big sleep before it gets too cold outside for them to move around.

Decreased Appetites

Preparation includes eating a good amount of highly-nutritious vegetation and getting enough water to keep himself hydrated during his rest. However, this increase in appetite occurs even before temperatures drop. Once it gets a little chilly at night, appetites should steadily decrease as his body temperature decreases.

Safe Locations

He will also need to seek out a safe and suitable hibernation location. Since tortoises are territorial, chances are good he already has a good spot picked out. But sometimes other animals take over a tortoise burrow or move into a spot they’d planned to hibernate in.

In those cases, tortoises need to think fast and dig even faster to get underground before it’s too cold for them to function.

Emptying the System

Since tortoises will experience system-wide slowdowns, they tend to empty their bodies of waste well before it’s time to settle in for the winter. It wouldn’t be good to be full of waste products for months on end with a sluggish digestive tract.

They may defecate and urinate much more frequently in the days or weeks leading up to hibernation. Some will save it all up for one last big release right before they dig into the burrow. Don’t be surprised if you see a lot more urates in an area with wild tortoises just before the weather turns cold.

Many tortoises will use those last warm rays of the sun to stimulate their systems, too. It’s not uncommon for wild tortoises to congregate in known basking locations to relieve themselves one last time.

Last Drinks

To aid in all that last-minute defecation, wild tortoises may seem extra thirsty. You can often find them gulping down what seems like excessive amounts of water right before hibernation. That’s instinct again. More water means faster digestion and bigger waste output. Exactly what Mother Nature ordered for a clean out before nap time!

This is one place it’s actually okay for humans to help. If you want to help wild tortoises prepare for brumation, you can set out clean, fresh water in shallow dishes. Just be sure they’re not too deep—tortoises can drown in surprisingly small amounts of water. Put a ramp in the dish if it’s really large—this should help smaller torts who may accidentally fall in. Also, be sure to check the water dishes regularly, just in case.

Where do wild tortoises hibernate?

The location of hibernation for tortoises will depend on where they live and what species they are. It all comes down to physical attributes and instinct. A desert tortoise, for example, isn’t going to find suitable hibernating locations in a tropical area because that’s not what they were built for.

Each species has evolved a specific set of physical characteristics to create a den and sustain life during hibernation. They have also developed instincts to go along with those tools. Combined, these tools have allowed tortoises in a wide range of environments to find unique ways to survive tough winters.

Most will go and stay underground for hibernation. They use their strong leg muscles and sharp claws to dig deep burrows in soft ground. Their hard shells act like shovels, too. The depth of the den will depend on the size of the tortoise and the environment.

The main goal of the burrow is to keep the tortoise’s body at a somewhat constant temperature. Most will be under 60 degrees Fahrenheit. Again, the actual temperature of individual dens will vary.

When do wild tortoises hibernate?

We can’t stress this enough: hibernation is highly dependent on the tortoise’s location and species. Each species has evolved to begin hibernation prep once temperatures begin to drop. But that trigger temperature will vary between species and natural habitats. That makes it tough to estimate when wild tortoises will begin hibernating.

The best estimate we can give is between October and April. However, this can vary by as much as a month. Add to this the possibility of a warmer fall or shorter winter and the timelines get a bit blurry. Since tortoises can’t read human calendars, we just need to leave it to the tanks to figure it out for themselves.

What are some dangers for hibernating wild tortoises?

You’d think that being underground and sleeping through the winter would be pretty safe. Unfortunately, this is not always the case. Whether due to predators, humans, or strange weather patterns and bad luck, sometimes things go wrong for wild tortoises during hibernation.

Predators

Winter is the hungry time for most animals. Tortoises are a convenient and tasty meal in the middle of the cold months. Any predator that can dig in soft earth can find a sleeping tortoise. The poor reptile won’t be able to put up a fight. While their shell will provide protection from many things, a very hungry predator with strong jaws, sharp claws, or the determination to get dinner can crack it.

There isn’t much that humans can do to protect hibernating tortoises. While it would be nice to think of ourselves as their saviors, it’s important to keep in mind that Mother nature has her own plans.

Freezing

A perfect hibernation burrow will be well below the frost line. Inexperienced, weak, old, or sick tortoises may not be able to dig their burrows deep enough to escape the frost. If this is the case, there is very little that can save them. Frost will kill most tortoises, as it will lower the body temperature too low.

Again, it’s best not to interfere. If you notice a tortoise that hasn’t dug deep enough to clear the frost line, any intervention could actually lead to its death instead of helping. Don’t throw more dirt over them and don’t pile on leaves or branches.

Drowning

Choosing a brumation location too close to a water source is another way tortoises can die during hibernation. Drowning can happen quickly and without warning. Heavy rainfall or melting snow can quickly fill a tortoise burrow.

Since torts can’t produce their own heat, they have no way of drying out and warming up, even if they were to survive a flood. This is another way they can freeze or become too cold in the wet ground.

Should I wake a hibernating tortoise?

No, never wake a hibernating wild tortoise! They know what’s best for their own bodies. Intervention by well-meaning humans has killed more wild tortoises than we’d like to think about.

Even if you believe it’s warm enough outside for the wild tortoises to wake up, be patient. Tortoises are far more sensitive to temperatures than humans are. Their instincts will tell them when it’s safe to wake up and shake off the sleepies.

Conclusion

Understanding how wild tortoises hibernate is the best way to prepare yourself for owning a pet tortoise. While we’ve done our best to cover this topic in detail, it’s still up to you to find specific information on your species of tortoise and their needs. Be sure to check their natural habitats and their natural brumation cycle. Your breeder should be able to provide all of this information to you. It’s also good to check with your vet.

All in all, hibernation of tortoises in the wild or in captivity should not be a scary topic. They evolved to hibernate and so they already come with the instincts to do it right. As long as you provide your captive tortoise with appropriate food, water, and burrow materials, and you keep the enclosure at the appropriate temperature and humidity for your species, your sweet little friend should come out of hibernation refreshed and ready for a fun-filled spring and summer with you.

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