Veterinary & Aquatic Services Department, Drs. Foster & Smith, Inc.
Humidity requirements for pet herps vary over a wide range. At one end of the spectrum, species such as green iguanas, geckos, chameleons, and water dragons need moist, tropical rainforest conditions. At the other end, species like the desert spiny lizard and the crevice spiny lizard require arid conditions. Whichever humidity level your pet requires in his enclosure, it must be monitored and maintained continuously. If the humidity would drop too low, your herp may not shed his skin correctly, and develop other health problems, such as egg binding in females. If humidity is too high, your pet could suffer severe fungal infections, or even pneumonia.
Research and Observe
Temperature and humidity conditions in your terrarium require ongoing observation and precise adjustment when needed. Before setting up your pet's microclimate, research and learn everything you can about the needs of your particular pet. So specific are the needs of various species, that keeping different species together in the same enclosure is strongly discouraged. Also, be sure to take into account your local climate, and the type of climate control operating in your home. Humidity needs may change depending upon the status of your pet. For instance, during shedding, higher humidity levels are often helpful.
Moisture Variables
The amount of moisture in the air of the enclosure or aquarium is controlled by three variables:
- Ventilation
- Temperature
- Introduction of water into the atmosphere
Ventilation
Full enclosures with small side vents conserve heat and humidity. These are best for tropical and other species with high humidity requirements. Glass and plexiglass aquariums with wire mesh tops allow heat and humidity to more readily escape. These are best for desert and other species with low humidity requirements. If you need to maintain high humidity levels, avoid enclosures made of wood or pressboard which may rot or swell when moist. Regardless of type of enclosure, adequate ventilation and regular cleaning are necessary to control the rapid growth of bacteria and mold. With any type of enclosure always make sure all electrical connections are waterproof.
Temperature
In most cases, an ideal herp environment will be maintained through the use of multiple heat sources. For instance, an under-the-cage heat mat will keep the base temperature of the enclosure at the proper level, while a basking light or ceramic heater will provide a warmer spot. Most herps do best when they have a temperature gradient within the enclosure so they can move to a warmer or cooler spot, as desired. To monitor the temperature, at least two thermometers should be used. One should be placed near the floor of the cage where it is coolest, and one near the basking area, where it is the warmest. The thermometers should be checked at least once daily to be sure the heat sources are working properly.
The warmer the temperature, the faster the water sources in the enclosure will evaporate. Since most enclosures will be warmer than room temperature, the water in the cage will evaporate faster than water outside of the cage. This means water bowls, pools, damp moss, and other water sources need to be checked frequently and water added as needed.
