Worlds Smallest Chameleon

Worlds smallest Chameleon- Brookesia micra (YK)

The Brookesia micra is the name given to the smallest chameleon found in Madagascar. The discovery was made very recently in February 2012 and this is mainly because this species only grow up to a maximum of 30 mm enabling it to fit on the head of a matchstick. This made it difficult for even the experienced experts to find them. It is said that the Brookesia micra has evolved to become this size to help protect itself from predators such as birds on the island and their small size help them to hide amongst the fallen leaves where they live during the day. At night they climb up tree branches 10cm off the ground to sleep. Other theories state that the size of these chameleons are the result of 'insular dwarfism'. Insular dwarfism is an important mechanism to help particular species survive harsh conditions such as that faced in Madagascar where there are many species thus resulting in competition for land, food and water. A smaller species would in theory make thermoregulation easier and more efficient which also contributes to the higher chance of survival for Brookesia micra.

Thermoregulation in Brookesia micra

Brookesia micra have identical features of a normal sized chameleon like changing colour to hide from predators and having 360 degree eyesight. Therefore they also have the same thermoregulation system.Chameleons are Heliothermic which means they directly receive sun rays in order to warm up but this restricts chameleons from doing many activities and as a result have many adaptations to aid its body temperature regulation. This includes having hinged ribs allowing them to flatten their body thus increasing the surface area of the side exposed to the heat source.

However, this special type of chameleon have an ability to change colour during thermoregulation. Changes in color help them not only to camouflage but to regulate their body temperatures. The chameleon will darken the side exposed to the heat source to increase heat absorption and may lighten the opposite side to retain heat once absorbed.