Panther Chameleon - SG

General

Panther Chameleons (Furcifer pardalis) are large bodies reptiles which are predominantly found in the Eastern and Northern regions of Madagascar. They are highly adapted to life in the tropical forest biome.

Male chameleons have an average length of 43 cm, whereas females are considerably smaller (around half the size). Clutches of 10-40 eggs are laid by females after mating, which typically take 240 days to hatch. The stress exerted on the bodies of female panther chameleons means they only live 2-3 years after laying their eggs.

Thermoregulation

All reptiles are ectothermic, meaning they rely on external sources of heat and their body temperature fluctuates with the temperature of the environment. Chameleons are Heliothermic animals, so they use the sun's rays to warm themselves.

If the panther chameleon is too cold, it will try to absorb more heat from the environment: If the panther chameleon is too hot, it will try to increase heat loss to the environment: The fact that chameleons are ectotherms means they not only require less food, but more of the energy and nutrients gained from food can be converted to growth. However, they are less active in cooler temperatures so are more vulnerable to predators and unable to take advantage of food when they are cold. In order to heat themselves quickly, their heart rate increases as they bask allowing warm blood to quickly circulate to other parts of the body. Once the required temperature is obtained, the heart rate decreases to slow down heat loss so the animals can stay more active for longer.
 * it climbs to the end of tree branches to bask in a sunny area
 * hinged ribs allow it to flatten its body and increase the surface area so more heat can be absorbed
 * it may become darker in colour for maximum absorption
 * it will move to shaded areas which are out of the sun
 * it reduced the surface area exposed to the sun
 * it may become lighter in colour so more heat is reflected as opposed to being absorbed

Mechanism of Colour Changing

Chameleons use their impressive natural adaption of colour changing to both camouflage from predators (when relaxed) and to display themselves during social interactions (when excited).

Scientists previously believed that the colour changing ability of chameleons was due to the expansion of pigment containing chromatophores under the skin. However, investigations using techniques such as microscopy and photometric videography have in fact shown that each of the chromatophore levels of the chameleon skin have thousands of guanine nanocrystals arranged in a regular lattice structure. They can reflect any colour of visible light depending on the distance between the crystals (eg. blue/green when the crystals are densely packed and red/orange when the crystals are further apart). Female and juvenile chameleons are unable to change colour due to a lack of iridophore cells which are present in males.