Thermal Gradients

Firstly, back to basics.  How are reptiles different from other animals?

Animals such as mammals and birds have the same body temperature at all times (within a few degrees) whether they are exposed to a cold winter day or a hot summer afternoon. 

However, expose a reptile to a cold winter day and it's body temperature will drop down until it is almost the same as the ambient temperature, its metabolism will slow right down and eventually it will die.  Expose a reptile to a hot summer afternoon and its body temperature will quickly rise until it reaches critical point and becomes fatal.

Reptiles and amphibians are ectothermic which means that these animals draw their body heat from the environment and regulate their preferred temperature through behaviour. To increase body temperature they will bask in direct sunlight or on a heated surface such as a rock. To decrease it they can retreat to the shade, climb a shrub or tree, or enter a burrow or water.

When keeping reptiles as pets, enclosures should therefore provide a Thermal Gradient with an appropriate range of temperature that can be regulated using a thermostat and monitored using a thermometer inside the cage.

This normally involves a ‘hot spot’ for basking at one end of the cage and the opportunity to move well away from this to cool off. 

                              hot corner

                                                                                        cold corner

Ideally there should be a difference in temperature of approx 5-7 degrees between the hot corner and the cold corner, but this will depend on the size of the enclosure.

Gidday, well done on new forum!

{ 5:41 PM, 31/5/2006 } { Posted by Pilbaralad }

Great idea on a West Aussie forum, most online forums are interstate keepers and can't relate to West Aussie regulations etc. By way of introduction I live in Newman in the Pilbara and I am a registered CALM reptile relocator. I am in the process of putting together all the accessories for Vivarium as the ready made ones are expensive for the sizes offered. Im actually planning on buying a computer cupboard from comfortstyle furniture and replacing the doors with glass sliding doors, that way I have a nice large brown laminated enclosure, which looks good inside. Question, will a 100 watt ceramic lamp throw enough heat to the floor of a 900mm high enclosure?

100W Ceramic Heater

{ 2:37 PM, 1/6/2006 } { Posted by reptiletrader }

Nice to meet you Pilbaralad! Welcome to our Forum.

The Thermal Gradient in your enclosure will be vertical instead of horizontal like our diagram above. This means that the floor of your enclosure will be the cold end and therefore your heat source does not need to reach the floor.

As a heat source for your enclosure a 100W Ceramic Heat Emitter is fine - you could even go to 150W or use an infrared nocturnal lamp of the same wattage. However, considering you live in a fairly warm climate your ambient temperature may allow you to get away with a lower wattage heat source. Use a dual probe digital thermometer to monitor the max and min temperatures in the enclosure before deciding on the wattage.

If you would like a basking place on the floor of your enclosure for your reptile without disrupting your Thermal Gradient you could use an electric heat rock instead.

You will find a couple of choices on our catalog at www.reptiletrader.com.au.