How do Chameleons change colour ?

Parsons Chameleon

 Although many people have a misconception that the Chameleons change of skin colour is targeted toward blending with the surroundings, that is not strictly true.  The main reasons for skin colour change include mating behaviour, emotion exhibition and temperature adjustment.  For instance, if a male Chameleon tries to attract females, it may exhibit lighter and brighter skin colours.  On the other hand, since Chameleons do not possess the ability to maintain body heat, the lizard can achieve optimal temperature with the help of darker shades to absorb heat, and lighter shades to release heat (Bates, 2014).  The range of colours is enormous, including blues, reds, greys, pinks, yellows, purples and more.  However most species of Chameleons can only change between a limited numbers of colours (Raxworthy, 2014).

For example most Veiled Chameleons will change colours mainly using greens, yellows and dark greys or black. Going back to the point about whether or not Chameleons can change colour to match their surroundings, we did find a study from the New Scientist that shows some species of chameleons like the Smith’s Dwarf Chameleon can actually change their colours to almost match their surroundings when under threat from different species. In particular birds and snakes.
www.newscientist.com/article/dn13944-chameleons-finetune-camouflage-to-predators-vision.html#.UfEwGY21GBQ

How does the Chameleon change its colours ?

On a physical level, colour changes in Chameleons involves skin cells. Chameleons have outer skin that is transparent, and there exist a number of skin layers having special cells known as chromatophores. When signals are received, these cells expand and contract.  Since these cells contain colour pigments, expansion and contraction results in different skin colours (Clark, 2005).  For instance, if red cells become fully expanded, then the skin colour of the Chameleon appears to be red.  On the other hand, when green cells seem to expand, a Chameleon appears to be green.

 

References:

1) Bates, Mary.  “How Do Chameleons Change Colours?” Wired.  Howard S.  Mittman, 11 April 2014.  Web
2) Clark, Rulon.  “How do chameleons/anoles change colours?” 
Cornell Center for Materials Research (CCMR).  Cornell University, 27 January 2005.  Web
3) Raxworthy, Christopher.  “A Truly Bizarre Lizard.” 
PBS.  Public Broadcasting Service.  Web

Images:

1) Main image supplied by Dan Fegent

Chameleons Tail

Panther chameleon
Most Chameleons have prehensile tail, which basically means that the tail allows the creature to hold onto branches and move from one branch to another, in order to make its life easier when it is above the ground.  In fact, the meaning of “prehensile” is ‘able to grasp’ (Prehensile tail, Wikipedia).

The length of a tail depends mostly on the species and age of the Chameleon in question.  For instance, a 9 month old Veiled Chameleon could possibly have a tail of approximately 7-inch in length, where as a 9 month old Pygmy Dwarf Chameleons tail would be considerably smaller.

Since the creature has prehensile tail, the tail cannot fall off and then re-grow, which happens with a number of other similar lizards (Chameleon, San Diego Zoo).  In other words, a Chameleon cannot drop its tail.  Many people are also of the opinion that the tail is used for balancing purposes, and it makes sense to a certain extent.  

As far as colour of tail is concerned, it depends on the Chameleon.  Moreover, since the creature is able to change its skin colour based on temperature, light and mood, the tail colour changes to suit.

We have noticed that when a Chameleon is about to go to sleep, it curls its tail, whether this is to make the Chameleon appear smaller and compact keeping it better hidden or it could be simply that it’s the most comfortable position for the Chameleon to sleep in, we are not sure.

 

References:

1) “Prehensile tail.” Wikipedia.  Wikimedia Foundation, Inc., 26 December 2013.  Web.
2) “Chameleon.” San Diego Zoo Animals.  San Diego Zoo Global.  Web.

Images:

1) Main image supplied by Cow Yeow