BIOLOGY AND BEHAVIOUR
Green Tree Frogs are easily the best known of all Australia's frogs. They are also both the most popular and most common pet frog. They make excellent pets as they are long lived, easy to maintain and seem very well adjusted to life in confined spaces. They will also tolerate a small amount of handling and for this reason have been very popular as children's pets. They occur throughout Australia with the exception of the arid west and the colder southern parts of the country. Reaching an adult size of over 10cm, they have been known to live beyond 25 years.
HOUSING
A variety of different vivariums may be used to house Green Tree Frogs. The minimum size for 2- 4 adults is 45cm long x 60cm high x 30cm deep. They must be water proof and non-toxic. Glass and plastics are the best materials. For visibility, longevity and aesthetic appeal, a glass aquarium is best. Any enclosure must be secure and escape proof. A tight fitting wooden or aluminium frame covered with fly-mesh provides the necessary ventilation and security while allowing the valuable UV light to reach the frogs.
TEMPERATURE AND HEATING
It is imperative that Green Tree Frogs be kept warm. Prolonged exposure to temperatures below 10°C will result in the death of your animals. If you do not have a purpose built heated room, the most effective way to heat your enclosure is by the use of an aquarium heater placed in the water. The water should be heated to 24-26°C and this should ensure that the air temperature remains above 18°C. A waterfall or some other form of water movement will increase evaporation and help maintain and stabilise the temperature and humidity of the air. If excessive heat loss is occurring, part of the lid may be covered with glass or plastic. Be sure however that the cover is not beneath the light fixture as it will stop the necessary UV light from reaching your frogs.
LIGHTING
Although Green Tree Frogs are largely nocturnal they shelter during the day in areas exposed to sunlight. It has been observed that in captivity a failure to provide ultra violet light has resulted in stunted and deformed growth. Most animals with a high UV requirement need light in the 250ηm-400ηm range. UV fluorescent tubes should be replaced every 12 months, even if they are still running, as their UV output diminishes and at this point they are no longer useful. Fluorescent fittings should always be approximately 40cm from the tank floor as the UV emitted will only penetrate this far. Lights should be placed on a timer for at least 6-8 hours a day - this helps to stimulate frogs and provides light for plant growth. For breeding, you may need to alter your day length with the seasons.
WATER
Maintaining water quality is an important part of amphibian husbandry. Fortunately Melbourne's water supply is suitable for Green Tree Frogs, and only requires the removal of chlorine before it can be used. Water should be changed regularly; the frequency of changes will be dictated by the amount of water, the number and size of the frogs the presence/absence of aquatic plants and the presence/absence or type of filtration provided. A standard 3ft aquarium with 15cm of water over half its area, three adult frogs and no plants or filtration may require changing weekly.
When changing 100% of the water in a tank it is best to allow for the temperature change. Be sure that your heater is powerful enough to heat the water up to the required temperature quickly so as not to cause the tanks temperature to drop for more than a few hours. Although Green Tree Frogs can easily climb glass, it is important to provide numerous escapes from the water especially in the corners where young frogs tend to get trapped. Small frogs are often too weak to break the surface tension of the water when they have nothing but slippery glass to cling to. Part of or all of your tank may be covered in water. Green Tree Frogs will successfully spawn in as little as 10cm of water.
FEEDING
In nature most frogs are almost totally insectivorous. Calcium powders are available at many pet stores and should be mixed in equal quantities with a multivitamin powder then dusted on food before feeding. Place your food insects in a plastic bag with a pinch of calcium / multivitamin powder and shake it till the food is well coated. By doing this about 1/2 the times you feed your frogs, calcium deficiency will be avoided. Do not mix large quantities of this mixture at a time. It does not store well after mixing as the calcium can denature the vitamins (refrigeration will slow this process).
Variety is the spice of life and even a frog knows it! Feed your frog a variety of insects and invertebrates and you should have few diet related problems. Juveniles will happily eat flies, moths, small crickets and cockroaches, and should have food available to them AT ALL TIMES. If young frogs are kept warm and offered plentiful food they will reach breeding size in about 8-12 months. Adults will eat almost anything that moves and fits in their mouth, they should be offered about 10-20% of their own body size in food spread over 2-3 feeds each week. During winter or when your tank temperatures are reduced your frogs will need less food. It is important to increase and reduce food in both quantity and frequency with the changing temperatures of your enclosure. Remove drowned insects so as not to foul the water, or feed your frogs individually by holding the insects on tweezers.
HANDLING
Green tree frogs do not like being handled. If you must handle them make sure your hands are wet as the oils on our skin and damage theirs.
DISORDERS
Chytrid fungus
Symptoms are varied they may include lethargy, redding of inner thighs and lesions on other parts of the body.
Overcrowding and stress
They can become stressed by being moved from one tank to another, being handled having inappropriate temperature, humidity, incorrect lighting and overcrowding. Soft bones / metabolic bone disease This occurs only when frogs are not obtaining sufficient calcium and vitamin D in their diets. They may be hunched or twisted and may have trouble moving about the tank.
