The Big Sleep | Hibernation & Brumation

There has been and  always will be a significant amount of discussion regarding the terminology used to describe the ‘wintering’ of ectotherms specifically reptiles. ‘Wintering’ can impact eating and many other aspects of reptile behavior. Reptile captive care doesn’t have to include ‘wintering’. According to their own experience(s), some have stated that there’s a significant uptick in fecundity when ‘wintering’ takes place.  Here’s the truth behind the two words. Hibernation was and is used to describe endothermic animals going into a ‘hibernaculum’ then overwintering by entering a state of torpor in which the animal enters a state of unconsciousness (sleep) for a period of time. This occurs when the proper parameters are met such as reptile lighting.  The very best thing about this article, I get to use the word ‘butt-plug’ in a scientific context.

Hibernation & Butt Plugs

It’s been ‘common knowledge’ to numerous people that bears develop a rectal plug while they hibernate, this was thought to be a preventative measure to keep the bears from eating. However, this was found to be erroneous. That’s not even the best part, the cool thing, I found interesting, is this.

Some bears are not actually asleep the entire time they are in hibernation!

That’s right, they wake and actually groom during hibernation which is how the plugs are developed; some even walk outside their den to defecate then go back inside the den and go back to sleep. Think of it as the midnight bathroom break where you wake in the middle of the night to use the bathroom then go back to bed. If you want to read up on this particular subject check out this website:

According to The Obligate Scientist the word hibernate is derived from Latin for wintering quarters. So to hibernate means to stay indoors, nothing more than that. There is no physical state that is or was ever intended to be used when the word was said and written down. So why the change and where did the word brumation come from in the first place?

Brumation Origins

Again turning to The Obligate Scientist who was so gracious as to research and discover where the word brumation originated. The word brumation first came into the English language in 1965 and was coined in an article titled Hibernation in the Horned Lizard, Phrynosoma m’calli. Comparative Biochemical Physiology. Vol 16 pp. 103-119 (if you have $32 you don’t need you can read it yourself using the link). He essentially stated that ectotherms did not enter the same state of ‘sleep’ that mammals did and therefore we needed a new word to describe their physical state during the specific times when they enter this time of inactivity. In a number of later papers the term brumation was brought into question as being false and therefore shouldn’t be used in scientific papers. One in particular which you can see on The Obligate Scientist article linked above pretty much sums it up for me. Gordon R. Ultsch wrote in Ecology and Physiology of Hibernation and Overwintering Among Freshwater Fishes, Turtles, and Snakes. Biological Reviews 64(4), pp. 435-515. I got the paper and read it and one sentence hit me as it did the other author.

“The term hibernation asserts no specifics about the physiological details of the hibernating organism.”

To me that should end the discussion whether or not reptiles (ectotherms) hibernate. We do not today understand all the physiological details involved in the slowing down and inactivity of animals during periods of ‘dormancy’ which occurs prior to the breeding season.

Everyone Hibernates

There has been some recent discussions within the groups I frequent on some of the social networks about certain species of reptiles not hibernating. This is utterly false; bottom line. The reasoning behind this thinking is evidently there is an impression that said reptiles do not experience the necessary cold temperatures to trigger a period of hibernation. This is generally pointed out as being experienced by ‘desert’ species of reptiles.

At night, things cool off generally speaking; as an obvious factor there is no sunlight shining to warm the earth. During the winter season this is especially true because the earth’s axis for a specific hemisphere is pointed away from the sun and therefore the sun is not warming part of the earth (not directly anyway). Deserts experience serious temperature drops at night during winter. For those whom haven’t had the pleasure of being in a desert at night during the winter season let me clarify something. As my dad would say.

“It’s colder than a well diggers ass in the Klondike.”

I have been in the desert during various seasons; let me assure you. There are indeed fluctuations in temperature during the varying seasons in the desert.

Lizard Bearded Dragon Pogona sp

Bearded Dragon

In one group, someone stated and several agreed,  inland bearded dragons (Pogona vitticeps) (eBook Link) do not hibernate as it doesn’t get cold enough for them to do so in their native habitat. A quick search of Reptile Database and Australian Government Weather Page and comparing the maps would lead me personally to believe otherwise as most of the area where they are found are indeed ‘arid’ and said to reach 19 degrees as a low during the winter season. So I ask you, how is it possible,  with lower temperatures that an ectothermic animal such as a reptile wouldn’t slow down? There is less food available, it takes too much physical energy when looking at the cost/benefit ratio of capturing food. So they hibernate.

Everyone hibernates even humans do it to some extent. Think about it, winter sets in and for most humans, we come indoors; sit by fires, wrap in blankets and for the most part are less active. While this is not the dictionary definition of hibernate, which according to is “to pass the winter in a torpid or resting state” it is a natural state of most organisms to ‘slow down’ during the winter season.

Snuggling In

To wrap this all up in a nice warm blanket let’s review shall we. Brumation is jargon and not recognized by dictionaries. Therefore it shouldn’t be used to describe the lower activity rate of reptiles during the winter season. Inland Bearded Dragons (Pogona vitticeps) (link to our sister site captive care article) do in fact experience a winter drop in temperature in their native range, therefore they experience a period of lowered activity and less feeding. Most organisms on the planet experience a type of hibernation during the cooler months.

Now then as a final note, can we use the term brumation? We can as most of the reptile industry does anyway. However, we must be very careful to not differentiate it from hibernation as there is no evidence for such a distinction. That said, personally I don’t or at least try not to use the word brumation in common parlance. So now you have a better understanding of what it means to hibernate and that the word ‘brumation’ is in fact a jargon term.