Brumation Basics – December 2012

Brumation Basics

By Jonathan Rheins

INTRODUCTION
All reptiles and amphibians are ectothermic; that is, the environment in which they are found dictates their body temperature.  These animals have perfected the art of altering body position and their location within their surroundings to establish an ideal body temperature.  In the terrarium, this behavior is often demonstrated by animals moving in and out of localized “basking” spots.  In nature, this amounts to where the animal chooses to position itself in relation to the sun or other source of radiant heat.
During weather extremes many ectothermic animals seek refuge from the elements either underground, deep within rock fissures, or within any other acceptably insulated space.  This behavior is known as brumation,when the period of inactivity occurs during cold weather, and aestivation, when the weather is too warm for regular activity.
IN THE WILD
 
For wild herps, brumation and aestivation are basically survival tactics.  These behaviors are natural adaptations that allow them to slow down their metabolism drastically and survive for extended periods when conditions are simply too unfavorable for regular activity. While reptiles are generally rather tough creatures, they also often inhabit some of the harshest environments on Earth.
Central Asian (aka Russian) tortoises, Agrionemys horsfieldii,serve as a prime example of these principles.  During the winter months in most of their range temperatures can drop far below 0 degrees F with many feet of snow covering the ground.  Conversely, in the summer months, the temperature regularly soars over 100 degrees F.  When the weather reaches these extremes, A. Horsfeidii will be burrowed as far as 6’ under ground, and emerge only for 3 to 4 months after winter to eat, breed, and lay eggs.
IN CAPTIVITY
 
When maintaining reptiles in a terrarium setting, we must keep in mind that the activity of many herps is seasonally dictated.   This is part of their hard-wired instinct and it is much easier to embrace this fact than try to combat it by “tricking” an animal by manipulating lighting and heating.  By gaining a thorough understanding of an animal’s natural history and behavioral patterns, it becomes easier to interpret their behavior and adjust husbandry accordingly.
There are two general approaches to dealing with brumation behavior in the terrarium setting.  With species that undergo a true brumation in the wild, it may be acceptable to replicate this rest period for captive animals housed indoors.  Animals such as tortoises and box turtles that live outside may be allowed to enter brumation on their own, with minimal involvement on the part of the keeper.  For some species, such as cornsnakes, this annual fluctuation of temperature and photoperiod induces breeding and subsequent egg-laying.  In the wild, most temperate and sub-tropical herps reproduce during the spring and summer months, ensuring the young have ample time and resources prior to facing their first winter.
If captive propagation is not your goal, most pet reptiles can be kept awake year-round.  This alternative is the more typical approach, and requires fewer changes to the husbandry routine.  In these cases, photoperiod and temperatures are mainatained the same throughout the year.  However, it should be noted that even if no adjustments are made on your part, some animals will experience a “slow down” exemplified by inactivity and decreased appetite.
GENERAL CONSIDERATIONS
A thorough understanding of an animal’s natural range and the weather patterns therein can aid greatly in making brumation preparations for any herp.  Every attempt should be made to replicate the natural environment as much as possible.  The specifics regarding brumation timing and procedures will vary from one species to another, but some generalizations can be made.
Changes in lighting and heating regimens should be done gradually, as they occur in the wild.  Transitioning areptile from “normal” summer temperatures to winter temperatures overnight can be not only stressful to thereptile, but can have negative health implications as well.  Additionally, feeding should be slowly reduced as the temperatures are decreased.  Brumating herps do not hunt or eat in the wild, and having an empty digestive tract prior to entering brumation will ensure that no undigested food is left to decay in the gut and potentially cause illness.
In the spring, this procedure is essentially reversed; temperatures and photoperiod are gradually increased and feeding is resumed once all environmental conditions are stabilized.  For many reptile species this return to warmer temperatures and longer day length triggers courtship and breeding behavior.  The actual cooling process plays a significant role as well, specifically with spermatogenesis and ovulation in male and female herps respectively.
Only animals in ideal health and of good body weight should be considered for any sort of artificial or natural brumation.  Typically, herps eat and grow during the spring and summer in preparation for cooler months when food is scarce.  Although baby herps do brumate in the wild, it is out of necessity.  Most hobbyists and breeders wait until an animal is in its second or third year prior to allowing it to undergo a full winter cool-down.
CASE STUDY: BEARDED DRAGONS
As one of the most popular and prevalent pet lizards in the US, it seems only fitting that we look at the details of brumation in bearded dragons, and its implications for the average keeper.  Many first time bearded dragon owners become understandably alarmed when their normally ravenous dragon suddenly begins sleeping all day and losing interest in food. However, the vast majority of mature dragons will show marked changes in behavior during different parts of the year.
In the United States, most bearded dragons that have reached sexual maturity (typically 12-18 months) will begin to show signs of impending winter dormancy beginning in mid-fall.  In southern California, where the author lives and breeds bearded dragons, animals begin slowing down by the end of September.  External cues such as shortened day length, lower temperatures, and fluctuations in barometric pressure all contribute to the onset of brumation in bearded dragons.
During this transitional time, most dragons will still enthusiastically eat their favorite foods, but may lose interest in less appealing fare. Basking behavior will often change as well, with animals spending less timeunderneath heat sources and more time in the cooler regions of the enclosure.
By mid-November most male bearded dragons will have stopped eating almost completely.  Female dragons tend to brumate as well, but males are more likely to exhibit more drastic changes in behavior.  Food should still be offered on a semi-regular basis as per the interest in food shown by the animal.
As the days continue to get shorter, and nighttime temperatures drop, one should not be alarmed to see their bearded dragon go for weeks, sometimes months, without eating.  Animals that are going through a normal brumation period will lose minimal body weight, and at no point should they appear skinny or weak.  However, it is normal for them to remain hunkered down in a cold and dark corner of the cage for days on end.
It is important to ensure that brumating herps, bearded dragons included, remain properly hydrated.  The majority of their normal water intake is via the foods that they eat.  So when they are off food for the winter, a water bowl should always be available.  Alternately, adult dragons can be given a 10-minute soak in warm water once or twice a week to allow ample opportunity to drink.
Most of the author’s adult dragons begin “waking up” around the beginning of March.  As the ambient temperature begins to increase and the days begin getting longer again, the dragons will begin basking more often, and showing a gradually increasing interest in food.  By April, male bearded dragons will begin displaying their full breeding behavior.  Darkened beards, head bobbing, and courting of any receptive female can be expected.
When temperatures have stabilized in mid to late spring the majority of lizards will have resumed a normal feeding schedule, and should exhibit more typical basking behavior.  It should be noted that some male dragons will be less inclined to eat when they are housed with a female.  These animals will often be more concerned with breeding than with eating.
FINAL THOUGHTS
To the uninitiated, the entire brumation or aestevation process seems quite unusual, and entirely foreign.  As mammals, we find the idea of going for extended periods of time with little to no food to be alarming, and a great cause for concern.  However, we must remember that reptiles are a very ancient and well-adapted group of animals that have evolved in such a way as to survive when and where most other organisms could not.
By familiarizing yourself with the underlying biological implications of the brumation process, one can become better prepared to recognize and accommodate these behaviors in the terrarium setting.  While some concessions must be made, overall, the best results are observed when herps are allowed to follow a natural seasonal cycle.
Behavioral and physiological changes in tune with the environment are part of what make reptiles and amphibians the creatures that they are.  If we can identify and embrace these behavioral changes, rather than allow them to concern us, it will only allow us to better care for our charges, and ensure that our herps live the most natural, and comfortable life that they can.

Raising Grassland Species of Tortoises

Grassland Tortoises

By Jennifer Greene

With the advances in tortoise husbandry over the last few decades, more and more captive bred baby tortoises of numerous species are becoming more readily available.  Having captive bred baby tortoises to start with as pets is typically much easier than trying to acclimate wild caught specimens; however, a new problem arises with the care of baby tortoises as compared to their sub adult/ adult wild-caught counterparts.  This problem is the raising of baby tortoises in a way that results in adult animals that exhibit the same level of health in terms of weight, shell condition, and longevity that their wild counterparts experience.  Initially, many keepers could not keep baby tortoises alive, with many babies dying while being kept in the same conditions that adults were thriving in.  Some keepers were able to raise babies, but they developed minor to severe shell deformities, known as “pyramiding”, or the babies they raised experienced significantly shortened lifespans, living only 10 to 20 years compared to the often 100 year life span of wild tortoises.   This article aims to cover some of the more recent advances in neonate and young tortoise husbandry, with the goal of helping keepers better raise their tortoises to healthy and long lasting adulthood.

Baby Sulcata Tortoise

One aspect of raising baby tortoises that is often overlooked initially is the natural history of where the particular species is from, and the conditions in that climate at the time the eggs usually hatch.  This is important to note, as certain species inhabit extremely different microclimates as hatchlings compared to their adult counterparts.  One such example is the Sulcata Tortoise, or African Spur Thigh Tortoise.  Adults graze the grasslands of the savannah, often going for prolonged periods without water and tolerating extreme heat.  Neonates kept in similar conditions with little access to water and extreme heat end up with high mortality rates and stunted or deformed animals.  Similarly, neonate Greek Tortoises from the extreme north of their range typically hatch later in the season, and often spend a significant amount of time (up to several months) hidden in their incubation burrows, absorbing their yolk before going straight into their first hibernation season. (Kuzmin, 98)

With this in mind, be sure to thoroughly do your research before bringing home a baby tortoise.  There are some general guidelines that can apply to many species within an ecological niche, but beginners are advised to look for a reputable specialist in their preferred species, or to purchase appropriate books geared towards the species they aim to keep.   For species adapted to the grassland climate, including but not limited to Greek Tortoises (Testudo graeca), Russian Tortoises (Testudo horsfieldii, or Agrionemys horsfieldii in Russian literature), Sulcata Tortoises (Geochelone sulcata), and Marginated Tortoises (Testudo marginata), there are some general guidelines that can be used when raising hatchling tortoises.  A cage large enough to allow the babies to explore and forage is highly recommended; I typically prefer cages with a 24” x 24” footprint as a good starter size for young tortoises.

A cage this size allows enough floor space to provide the various microclimates within the enclosure that will ensure your baby tortoise thrives.  This size cage also allows for a wide range of temperatures, ideal for your baby tortoise to select the exact conditions within the cage it needs.  It is possible to use a smaller cage, or one that is narrower, but it will require more work to adjust the lighting and heating elements on behalf of the tortoise.  This size cage can be achieved with a glass terrarium (covering one or more sides is recommended, so as to prevent your tortoise from constantly attempting to go through the glass), tortoise table, or custom enclosure.  Similar floor space in the form of a 36” x 12” cage is also an option, but do keep in mind as an entirely terrestrial animal your tortoise will appreciate having as much floor space as possible.  In addition to traditional glass tanks, there are also various custom cages andtubs available that are specially designed for tortoises.  Choose what works best for you!

When it comes to lighting your baby tortoise, which bulbs you use and what wattages are used depends on your cage size and setup.  Tortoises, being diurnal reptiles, require not only heat but UVB as well.  There are two methods for providing this for your tortoise, either through a combination of basking lights andfluorescent bulbs, or with the use of a mercury vapor bulb.   Which you use depends on your tortoises, and size of cage.  In a larger cage, either 24” x 24” or 36” x 12” or bigger, you can use a mercury vapor bulb.  Mercury vapor bulbs, commonly abbreviated as MVBs, greatly simplify your lighting situation in addition to providing large amounts of visible light, UVB, and heat.  These types of bulbs are ideal for desert and grassland species of tortoises, but because they do emit so much heat, keep in mind you will need to monitor humidity more closely.  In smaller cages, or if you want to use a lower wattage bulb (mercury vapor bulbs do not come in wattages below 100), you will need to use a basking bulb in conjunction with a fluorescent tube light to provide heat, light, and UVB.  A benefit of using this method of lighting is that you can plug your basking light into a thermostat or rheostat, and more accurately control temperature that way.

Russian Tortoise

One aspect of keeping that has changed significantly over the last few years as compared to early attempts at raising tortoises is the level of humidity recommended for maintaining hatchlings.  Some breeders maintain babies of all grassland species with higher humidity continuously while they are young, while others prefer a regimen of regular soaking.  Alternatively, you can maintain a humid hide within the cage, which allows your baby tortoise to seek out an area of significantly higher humidity when it desires.  This area of increased humidity can be provided by the addition of damp New Zealand Sphagnum moss, or adding moistenedcoconut fiber to a section of the cage.  The addition of compressed coconut to the usual bedding (typicallybark or chipped aspen in most cases) also offers your baby tortoise the option to dig, and excavate its own hiding place.  It has been noted among some keepers that babies raised with the option of seeking out increased humidity often have smoother shells in better condition, which is something to consider when creating your tortoise setup.

Depending on which publication you consult, soaking regimens should consist of soaking your tortoise as often as twice a week (Leopard-, Vetter, 104) to only two to six times per month (Hermann’s, Vetter, 159).  Careful observation of your own tortoise(s) and their growth rates and overall health will help you determine just how often to soak your own tortoise.  Regularly misting the cage in the morning to create a morning spike in humidity should also be considered beneficial for young tortoises; a similar spike in humidity occurs in the wild during the morning, and this will help the cage from becoming completely bone dry from the use of heat lights.  Moisture is important for Mediterranean species of tortoises, such as the Hermann’s tortoises.  “Keeping the juveniles in conditions that are too dry results in a malformed growth of the shell even if they are properly supplied with vitamins and minerals.” (Hermann’s, Vetter, 157)  This observation applies to the African species as well, “keeping juveniles in an inappropriately dry environment causes an increasingly humped appearance of the carapace.” (Leopard-, Vetter, 109)  With this in mind, while your grassland tortoise does not need to be kept at tropical levels of humidity, do pay some attention to maintaining a level of humidity between 60 and 75% a majority of the time.

Sulcata on tortoise ramp bowl

Tortoise Ramp Bowls are a great way to provide an “easy access” water source

The feeding and supplementation of tortoises is often a controversial topic among keepers, with each breeder and keeper having their own ideas and methods about nearly every aspect of the topic.  Diet and supplementation of tortoises is such a large, diverse topic that a book should be dedicated to fully cover it, so I will only touch on key points here.  The first and foremost point is that supplementation should be included in your tortoise’s diet in some way, period.  The method of supplementation differs based on tortoise size and species.  One recommended method of providing calcium and added vitamins is not to dust the food directly, but instead offer calcium in the form of calcium blockscuttlebones, mussel grit, whetstones (for birds), or crushed eggshells.  The thought behind this is that dusting the food itself “forces” calcium on the tortoises in quantities they may not experience in the wild, and as yet it is still unknown what the correct dosage of calcium really is. (Leopard-, Vetter, 95)

If you do dust the food, be sure to dust lightly with a mix of calcium and vitamins recommended for vegetarian reptiles.  A light sprinkle, such as a fraction of a teaspoon, is more than enough for hatchling tortoises.  It is important not to skip supplementation entirely – while yes, over supplementation can adversely affect your tortoise’s health, not supplementing at all is equally as risky.

It is important to keep in mind when feeding grassland species of tortoises that in the wild, they roam vast distances eating plant matter that is rather low in nutrition content.  This means they eat lots of food, but get little from it – when raised in captivity with the rich diet most keepers provide for their tortoises, babies often grow unnaturally fast.  With this rapid growth comes “an increased susceptibility to diseases” (Hermann’s, Vetter, 159), and as a result excessively rapid growth should be avoided.  This can be done by reducing the amount of fresh, leafy green produce provided and instead offer hay and grasses.   For the larger species of grassland tortoises, such as Sulcatas and Leopard Tortoises, it is recommended that “Green feed should never be offered fresh or even wet.  It is always best to leave it to wilt slightly.” (Leopard-, Vetter 105)  This is the condition that baby tortoises would find their food most often in the wild, and should be replicated to a certain extent with captive babies.  The addition of pelleted food to the diets is also an option, withZooMed and Mazuri both offering excellent diets designed specifically for grassland species of tortoises. If your babies are stubborn, and refuse to eat their dried food or hay, a little tough love will often fix the problem.  You can also mix dried food and hay in with fresh and wet food, which will help make it more appealing.  Once your baby is accustomed to eating hay, offering it becomes much easier.   In addition to offering hay as a food item, consider liberally covering up to half of the cage with loose grass hay.  For smaller species of grassland tortoises, such as the Hermann’s, Greek, or Russian tortoises, this mimics the kind of leaf litter and dead grass they would normally be hiding under and foraging through in the wild.  The added security of being able to burrow under hay will help ensure your baby tortoise thrives in your care.

tortoises eating

Lastly, consider housing your baby tortoises at least part of the time outdoors.  On warm, sunny days between 75 and 90 degrees, keeping your babies outdoors to experience some natural sunlight can be extremely beneficial.  It is mandatory that they have the option to escape from the sun, and any good commercially madeTortoise PlayPen or similar item will provide a hiding spot with its design.  Due to their delicate nature, baby tortoises should not be left outdoors completely unsupervised.  Make sure someone is always home to keep an eye on the tortoise(s) when they are outdoors, not only to make sure they do not get too hot or too cold, but to prevent predation and theft.

Being familiar with your particular species of tortoise will help you determine appropriate weather conditions; wild Sulcatas for example never hibernate or experience the same level of cool weather that Russian tortoises do.  As such, they cannot tolerate the same cooler temperatures that Russian tortoises do.  Always carefully monitor your tortoises when they are outdoors.

In closing, there have been huge advances in the captive husbandry of neonate tortoises, making it considerably easier for even the novice keeper to raise a pet tortoise up from a hatchling.  As long as research is done to prepare for your preferred species, and the correct conditions are provided, a baby tortoise is no more or less difficult to care for than any other reptile species.  Buy a book, join a tortoise club, participate with specialized online forums, educate yourself on your tortoise before bringing it home.  And of course – when you do get it home, enjoy it!

Works Cited

Sergius L. Kuzmin The Turtles of Russia and Other Ex-SovietRepublics.  Frankfurt am Main: Chimaira 2002

Holger Vetter Hermann’s Tortoise, Boettger’s and Dalmation Tortoises Frankfurt am Main: Chimaira 2006

Holger Vetter Leopard – and African Spurred Tortoise Frankfurt am Main: Chimaira 2005