Care of reptiles
The Australian Museum keeps a variety of reptiles including turtles, crocodiles, skinks, dragons, and pythons.
Authority to keep Australian reptiles in captivity
The Australian Museum is a licensed exhibitor of vertebrate animals. The keeping of reptiles privately as pets is regulated by state and territory agencies and it is illegal to take any protected species from the wild without a permit from an authority. please see the Resources for keeping live animal page and follow the links to your relevant authority.
Reptiles are often seen as relatively inactive compared to mammals and birds, however they are ‘active’ both in captivity and the wild in their own right. Most reptiles simply move on a different time scale compared to their endothermic counterparts, for example a mammal or a bird may move or display a behaviour ten to fifty times in a single waking hour. A reptile on the other hand may move only once or perhaps five times in that same hour. Reptiles are therefore not limited in the behaviours they will do or the travel they undertake, they simply have a longer time frame. This comes down to how they acquire, maintain and use their energy which is considered in the ‘Environmental conditions’ section below, however this is a point worth considering when the captive environment of a reptile is being designed.
The natural history of each species is researched thoroughly to ensure that the enclosure is not only large enough but also features the important environmental features that the species would utilise in the wild. For example, arboreal and semi arboreal species such as Diamond Python, Morelia spilota spilota, and Central Bearded Dragon, Pogona vitticeps, require branches for climbing as both species feel safe off the ground and like getting close to the heat source.
Other enclosure furnishings include, rocks for lizards such as the Gidgee Skink, Egernia stokesii, to wedge themselves between as well as other more terrestrial species of skink to hide beneath. A series of hide boxes are also used at the Museum to provide a safe retreat for reptiles. Plants and natural substrates are also used to make the exhibits appear natural and appealing.
Once the needs of the animal are researched the enclosures are designed and constructed of strong plywood and pine framing by museum carpenters to ensure that the enclosures are both safe for the animals, keepers and visitors and secure to prevent unauthorised access and animal escape. An important design consideration is safe access for keeping staff that allow easy access to capture the animals for health checks, remove faeces as well as uneaten food and maintain the exhibit.
Humidity is kept low for desert species, but medium to high for species such as the Eastern Blue-tongue Lizard, Tiliqua scincoides scincoides, and Diamond Python, Morelia spilota spilota, which inhabit forested areas of eastern Australia. Although humidity can be beneficial for some reptiles, too much humidity can create damp conditions which favour mould growth which can lead to health problems. This is best combated by providing adequate airflow to the enclosure, therefore the large enclosures that house reptiles have large vents at the top of the enclosure.
Reptiles are exothermic, which means that the animal receives energy from the environment and maintains a preferred body temperature by warming up (moving towards a heat source) or cooling down (moving into the shade). In captivity it is important to provide a thermo-gradient, which is achieved by providing a heated end and an unheated end, which allows the reptile to warm up and move away from the heat source once the preferred body temperature is attained.
Heat is provided at one end from a 160watt Mercury Vapour Spot-light for arid and tropical species and with 60 to 100watt ceramic heaters for cooler temperate species. A thermostat is used to ensure that once a set temperature is reached the heat source switches off, this prevents the reptile from overheating as well as reduces the risk of fire.
Lights are on timers so that the animals are provided with 8 to10 hours of light a day (the number of daylight hours is increased and decreased based on the time of the year). Full spectrum (UVA and UVB) lighting is important for proper skeletal growth and to prevent metabolic bone disease, particularly in dragon lizards and turtles.
Reptiles have incredibly varied diets from live crickets and cockroaches for the Bearded Dragon, Turtles and Crocodiles to snails for the Blue-Tongue Lizard. A typical monthly shopping list for the Australian Museum’s reptiles includes the following:
- 1 apple
- ¼ cauliflower
- ¼ broccoli
- ½ sweet potato
- 2 carrots’
- 1 bunch of boc choy
- 4 strawberries
- 40 crickets or cockroaches
- 1 snail
- 400g kangaroo mince
- 100g whitebait fish
- 50g bait prawns
- 5 ‘pinkie’ mice
- 1 adult rat
Kangaroo mince, processed for cat and dog food is used as a good high-protein and low fat food source for lizards, turtles and crocodiles. The vegetables are cut up every few months, mixed together in a bucket then portioned out into equal bags of ‘Veggie Mix’, which is stored in the freezer and thawed and fed to turtles and lizards. Every two weeks the food is supplemented with a vitamin and calcium powder which ensures proper nutrition as well as promoting skeletal development and to prevent metabolic bone disease.
Does the Australian Museum feed live rats to pythons?
The short answer is no. The long answer is that snakes such as pythons require feeding every two to four weeks. Frozen rodents (including pinkie and adult mice for crocodiles and adult rats for pythons) are delivered to the Museum and stored in a freezer until required to be fed out. When needed, the rodent is thawed and brought to room temperature before being presented to the python. This is done for the following reasons:
- It is illegal to feed a live vertebrate to an animal.
- Rats bite! Even a highly venomous snake can be injured and even killed by even a young rodent.
- In the wild live prey can be released and avoided if the snake or other predator believes it is too dangerous to eat, in captivity however, it can’t escape the angry rodent.
- One of the main reasons people believe a snake should be fed live food is actually false, that is that predators “enjoy” hunting live prey and that it is somehow beneficial to their health and welfare. This is inaccurate since snakes rarely chase down prey and almost always wait patiently to ambush animals, thus using minimal energy.
- Freezing rodents kills any possible parasites, thus ensuring the health of the reptiles they are being fed to.
- From a time and cost standpoint it is much more effective to keep 100 rats frozen than it is to keep ten rats alive, this is especially true since captive animal institutions need to provide as good captive care (including behavioural enrichment) to live food as for any other animal being held.
All reptiles need to drink. Water dishes are provided for a few days a week for arid species and ad lib for other reptiles. Central Bearded Dragon, Pogona vitticeps, enjoy a monthly soaking in luke-warm water to maintain hydration and assist in healthy skin sloughing. The Diamond Python, Morelia spilota spilota, enjoys a swim in its small pond. Water dishes are cleaned with detergent, rinsed and refilled regularly.
Aquatic reptiles such as turtles and crocodiles over half of their enclosure filled with water, the remainder of the exhibit provides enough space for them to completely ‘haul out’ and remain completely dry. A filtration and heating system consisting of two large canister filters and two 500watt aquarium heaters maintains good water quality and temperature. The water is partially replaced every few weeks and bags of charcoal help de-chlorinate the water. Water is tested for pH, temperature, ammonia and nitrates levels.
Capture and handling
Growth information is recorded every two months to monitor the health of the Museum’s reptiles, however before this can be done the animals must be picked up and restrained to be measured and placed in a cotton bag to be weighed. All of the lizards are more or less used to being handled and are often used for visitor programs so are very easy to handle.
Pythons are handled through the use of a snake hook, which take the first (head end) third of the python’s weight allowing the keeper to pick up the last third of the body. Once the animal is picked up in this fashion it can be transferred to another enclosure, holding container or a cotton bag for weighing. A useful way to measure a python is to get it to move against a flat wall, once the head is at a known point along the wall you can mark when the tail is with a pencil and measure the total length later.
Turtles seem like easy animal to handle, however they have strong sharp claws and a nasty bite, making the only way to pick them up from the back of the shell over the tail. The, head neck and limbs are then free to inspect and the turtle can easily be measured and placed in a bag to be weighed.
Crocodiles, even young Freshwater Crocodiles, Crocodylus johnstoni, that are kept at the Australian Museum are difficult to capture and restrain. This is done by wearing leather gloves and quickly gripping the animal firmly by the back of the neck and base of the tail. It is important to secure the tail and body as soon as the head is secured as the crocodile will thrash and can hurt itself if not properly restrained.
The crocodile is then be placed in a bag, once inside the animal can be weighed then examined which can be done by locating and holding the head from the outside of the bag and with the other hand reach inside and securely hold the animal from the back of the head. Once the neck is firmly gripped the head can be released from the outside and the bag can then be gently peeled back to expose the animal for examination. The base of the tail is secured and the animal is rotated to examine the dorsal and ventral surfaces.
Crocodiles will happily open their mouth for it to be inspected by its keeper. The important thing to remember about crocodile jaws is that they have very powerful muscles that close them but relatively weaker muscles that open them so once they are held closed they cannot easily open their jaws to use them.
The reptiles at the Australian Museum are checked by a veterinarian every six months and are treated at a veterinary clinic if they show any signs of illness or injury. Good animal husbandry is the key to maintaining healthy animals in captivity however reptiles are known to be prone to certain conditions:
- Ulcerative Stomatisis (also known as Canker or Mouth Rot) a bacterial infection of the gums due to poor enclosure hygiene, early signs appear as swelling and hemorrhaging around gums. The condition can be treated by scraping away the mucus from the gums followed by rinsing the mouth with a 3% dilution of hydrogen peroxide and finally a course of antibiotics to stop the infection. Vitamin C supplements are advised in order to promote tissue healing. Improve hygiene in enclosure and review protocols. Reducing stress has also been shown to be beneficial in preventing such infections.
- Mites are parasitic arachnids, the main species of concern to reptile keepers is the Snake Mite, Ophionyssus natricis. These animals become established in collections due to ineffective (or the lack of) quarantine and husbandry protocols.Signs of mites include raised scales, tiny white specks on the infected scales (these are mite faeces). The mites themselves are small eight legged ‘dots’ that can most often be observed on enclosure floors. Routine use of mite spays and quarantining of newly acquired animals are controls mites.
- Ticks are parasitic arachnids that feed on the blood of vertebrates. The parasite can be found visually as a 3-12mm disk-shaped animal with its mouth parts buried into the host in easy to get to parts such as between scales, ear openings and between skin folds. Physical removal is the best option, this can be done by dabbing the tick with methylated spirits which will cause it to release and can then be removed using forceps. Ticks usually only occur with animals housed outdoors and the use of insecticides are not feasible. Regular inspections of all animals and quarantine protocols are the best preventive measures.
- Abscesses caused by bites or other injuries to the body that come into contact with hard surfaces, usually on the ventral surface. They can be diagoned as a hard lump beneath the skin. A veterinarian will need to make an incision and drain the liquid. This should be followed with a course of antibiotics.
- Various organisms such as Nematodes, Protozoans, Cestodes (round worms) and Trematodes (flukes) are internal parasites to reptiles. Signs include a drop in weight, body condition and lack of appetite and poor reproductive ability. Once the organism has been identified a specific medication can be prescribed by a veterinarian. Internal parasites can be treated through regular (monthly) use of wide spectrum worming medications such as Worm-Rid (Reptile Sciences®).
- Injuries caused by falls, burns, contact with physical objects and aggression between animals. These can be identified by looking for damage to scales, loss of tail tip and toes, these injuries should be examined by a veterinarian however all open wounds can be treated with an antiseptic such as Betadine.
- Sloughing Problems can occur from dryness in exhibit, lack of abrasive objects to assist sloughing, no access to water due to over-crowding or other health issue. This is identified by finding sections of unsloughed skin around tail, top of head and on toes. The condition can be treated by placing the animal in a water-tight container with 5cm of luke warm water until the un-sloughed skin has loosened.
- Metabolic Bone Disease (MBD) is a nutritional imbalance or a systemic illness such as renal, liver or thyroid disease. Signs include the inability to close jaws, postural abnormalities, bone fractures, lameness, muscle spasm, spinal curving and skeletal deformations. Treatment includes correcting husbandry practices and treating any pathological fractures. Oral doses of calcium glubionate twice daily (23mg per kg of bodyweight) and weekly injections of vitamin D3 (400 IU/kg) and calcitonin (50 IU/kg). The condition can be prevented by supplementing the diet with fortnightly calcium carbonate and vitamin D3 and providing access to natural sunlight or full spectrum UVA/UVB lighting when kept indoors.
Behavioural enrichment is the management of the captive environment in order to decrease the predictability of captivity and encourage animals to exhibit natural behaviours. The benefits of ‘enrichments’ if executed correctly are that such programs can increase physical and mental exercise of captive animals, thus improving the health and well being of animals in captivity. Although most enrichment programs have been developed for birds and mammals; reptiles, amphibians and even invertebrates now have enrichment programs, with such programs only being limited to a keepers imagination and commitment. Based on encouraging natural behaviours, enrichment programs are important educational tools to demonstrate natural history concepts.
Enrichment for reptiles at the Australian Museum consist of rearranging the feeding schedule and modifying the diets over time to make feeds unpredictable, this prevents animals from becoming lazy, inactive and complacent. A simple non-feeding form of enrichment is a scheduled re-arrangement of enclosure furnishings. Moving rocks, logs, branches and plants in the captive environment provides new opportunities to explore, also by moving heating equipment, new basking opportunities are available when being kept indoors.
- Online reptile care sheets. Australian Herpetological Society.
- Swan, M. 2006. Keeping and Breeding Australian Pythons. Mike Swan Herp. Books. Lilydale.
- Swan, M. 2008. Keeping and Breeding Australian Lizards. Mike Swan Herp. Books. Lilydale.
- Walls, J. G. 2007. Vivaria Designs. Advanced Vivarium Systems. Mission Viejo.
- Walraven, E. 2004. Care of Australian Wildlife. New Holland. Sydney.
- Weigel, J 1988. Care of Australian Reptiles in Captivity. Reptile Keepers Association, Gosford.
Chris Hosking , Interpretive Officer