Care of amphibians
Frogs are popular pets and display animals. The Australian Museum keeps a number of species of Australian frogs.
Authority to keep Australian amphibians in captivity
The Australian Museum is a licensed exhibitor of vertebrate animals. The keeping of amphibians 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 animals page and follow the links to your relevant authority.
Research into the natural history of the frog species is first conducted to make sure that the housing is appropriate and allows the animals to live long healthy lives. Frogs species differ in their need to swim once they have metamorphosed from the tadpole stage into adult frogs, so the housing of frogs does not always require large water areas. Green Tree Frogs and Striped Marsh Frogs do not swim often; Green Tree Frogs will sometimes sit in water, but otherwise acquire moisture from living in humid conditions. Likewise, Striped Marsh Frogs will use water bodies to spawn eggs but otherwise hide and catch their prey amongst thick vegetation.
A high level of humidity is key to keeping such terrestrial and arboreal frogs, and this is best achieved through the use of a terrarium, which is similar to an aquarium except with little or no water. Terrariums are water tight and are constructed of glass so that they can provide a humid environment.
Many species of frogs, such as Green Tree Frogs can generally live with other frogs in the same terrarium, however some species, such as the Striped Marsh Frog are territorial, with males defending water-filled objects and ponds which are potential breeding sites. Although tolerant of each other, care is taken not to over-crowd Green Tree Frogs. The Museum’s exhibit has four frogs sharing an enclosure 1000mm X 800mm X 500mm (Length X Height X Depth) in size.
The base of the enclosure is fitted with a drain and covered in smooth pebbles to provide easy cleaning and drainage. The frogs have sensitive feet so require smooth material to move across and sit on. Other materials such as sphagnum moss and coco peat is also used with frogs, however requires regular changing in order to prevent fungal growth.
Enclosure furnishings such as branches, ceramic pots, plants, stones and bricks are provided for the frogs to climb on, hide behind and under as well as provide a naturalistic feel to the display. Faeces and uneaten food are removed as soon as possible to prevent mould growth and prevent the spread of parasites.
Frogs like all amphibians 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, which allows the frogs 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 160 watt Mercury Vapour Spot-light which is on 8-10 hours a day. The other end is lit by a compact florescent tube, both of these lights provide an adequate balance of full spectrum (UVA and UVB) lighting, which are important for proper growth and health. The lighting arrangement provides a temperature gradient of 18oC at the cool end and 32oC at the warm end.
High humidity is maintained from the heat evaporating water from the dish, which needs to be topped up. Live plants such as bromeliads and bird-nest fern also provide a source of moisture in the enclosure.
Frogs will mostly only eat live food. The Australian Museum feeds its frogs medium and large sized crickets and cockroaches. Around six insects are fed over two feedings a week for most frogs, this amount can be increased or reduced depending on if a frog needs to gain or lose weight. Live foods are sometimes released into the enclosure so that the frogs can hop and chase after the prey and receive exercise. Another feeding strategy used is to hand feed the frogs, which allows the amount of food intake to be controlled and recorded as well as a way to condition the animals to sit in one location for a positive enforcer.
The live food is supplemented with a vitamin and calcium powder which ensures healthy bone growth and overall health. The insects (approximately 20) are placed in a plastic bag with half a teaspoon of powder, then shaken to quickly coat them before being fed out to the hungry amphibians.
Water is provided in a large shallow dish, the water dish is washed out and water changed regularly. An anti-fungal liquid is added to the water to prevent mould growth. The quality of water is an important factor when keeping amphibians in captivity since eggs, tadpoles and adult amphibians have permeable membranes which are used for gas (respiration) and gland secretion and are therefore more sensitive to dirty and contaminated water. Water is tested for pH, temperature, ammonia and nitrates levels. Exhibits at the Museum have been designed to be accessible to keepers and well drained so that they can be easily cleaned out. All surfaces and objects which are cleaned with chemicals are rinsed thoroughly to remove any chemical residue, which could otherwise harm frogs.
Frogs are captured for regular health checks and for recording growth since they can acquire injuries from falls and can rub their snouts on abrasive surfaces. Green Tree Frogs are much more tolerant to being picked up and will often stay on the hand, however even this species will try to jump during detailed health checks so are restrained by being held around the waist which prevents them from being able to jump away.
Frogs have sensitive skin and are therefore prone to bacterial and fungal skin growths, this is controlled by reducing organic material used in exhibits as well as regular anti-fungal treatment. The use of UV lighting and provision of supplements in the diet prevents growth and skeletal problems such as metabolic bone disease (MBD) which is often expressed in captive animals as a hunch-back.
Behaviour changes are also a concern, as less active and withdrawn frogs can begin to eat less and lose weight. The main health problem effecting frogs is obesity, which is best combated by promoting exercise and controlling the amount of food provided to each frog.
- Amphibian Ark. 2009. Husbandry standards and biosecurity. proceedings of the CBSG/WAZA Amphibian Ex situ Conservation Planning Workshop, El Valle, Panama, 12-15th February 2006.
- Mendelson, J.R. Pramuk J.B. Gagliardo,R. Pessier, A. Rothermel, B.B Zippel , K.C. Bevier, C. Preest, M. Crother, B. 2009. Considerations and Recommendations for Raising Live Amphibians in Classrooms. Herpetological Review, 2009, 40(2), 142–144.
- Poole, V.A. and Grow, S. (eds). 2008. Amphibian Husbandry Resource Guide. Amphibian Taxonomic Advisory Group. Association of Zoos & Aquariums.
- Tyler, M.J. 1996. Frogs as Pets: A Guide to Keeping the Australian Green Tree Frog. Graphic Print Group. Richmond.
- Walraven, E. 2004. Care of Australian Wildlife. New Holland. Sydney.
Chris Hosking , Interpretive Officer