Leaf chameleon (Brookesia micra)

The newly discovered Brookesia micra chameleon is the tiniest lizard ever to be described ⁽⁴⁾. With the independently rotating eyes and curly tail characteristic of all chameleons, Brookesia micra is coloured light grey on the head, back and tail, although the tail becomes orange then yellowish towards the tip. The sides of the body are brown, occasionally interrupted by dark brown spots, and the limbs are almost entirely dark brown. Spotted patterning appears to be a stress colouration, and unstressed individuals have a more or less uniform dark brown body, apart from a beige area in front of the eyes ⁽¹⁾.

Juveniles of Brookesia micra resemble the adults in colour and pattern. However, the tail is less colourful and is not usually bright orange. Juveniles are also able to change their colour pattern under stress. In adult male Brookesia micra the tail base is slightly more thickened than in females ⁽¹⁾.

Size

Male total length: 22.5 - 23.6 mm ⁽¹⁾

Female total length: 26.9 - 28.8 ⁽¹⁾

Male snout-vent length: 15.3 - 15.8 mm ⁽¹⁾

Female snout-vent length: 18.7 - 19.9 mm ⁽¹⁾

Active on the ground during the day, Brookesia micra roosts at night in low vegetation, around five to ten centimetres off the ground ⁽¹⁾. Although difficult to locate, the species does not move at all at night, thereby proving easy to capture ⁽⁴⁾.

Species from the Brookesia genus are unusual among chameleons in using their tail as an extra limb. Grasping branches is difficult for the diminutive Brookesia species and so they use the curled-down tip of their tail to provide added stability. X-rays of Brookesia tails have shown 20 vertebrae compared to the usual 50 of larger chameleons. They have also revealed that the tendons underneath the tail are well developed, enabling the use of the tail as a supportive ‘leg’ ⁽⁶⁾.

Scientists have said that Brookesia micra may be as small as a vertebrate with complex eyes can get, although it is impossible to tell for sure ⁽⁴⁾. It is also feasible that Brookesia micra may be exhibiting ‘island dwarfism’, a phenomenon whereby a species adapts over time to being restricted to a particular habitat, for example an island, by becoming smaller. The effect may be more extreme in the case of Brookesia micra, as dwarf chameleons may have originally evolved on the island of Madagascar, causing Brookesia micra to become even more miniscule when isolated on the smaller island of Nosy Hara ^{(5) (7)}. 

Brookesia micra is currently known only from two sites in the extreme north of Madagascar, both of which are on the small island of Nosy Hara ⁽⁴⁾. Its range appears to be restricted to one square kilometre on the island ⁽⁵⁾. Further investigation will be needed to determine whether this species is fully endemic to Nosy Hara ⁽¹⁾.

Brookesia micra was discovered in dry forest leaf litter scattered around eroded limestone boulders on Nosy Hara island ⁽¹⁾.

Brookesia micra is not yet classified on the IUCN Red List, but all Brookesia species are listed on Appendix II of CITES ^{(2) (3)}.

Due to its restricted range, Brookesia micra is particularly sensitive to habitat disturbance ⁽⁵⁾, and may be threatened by habitat loss and deforestation in Madagascar ⁽⁴⁾.

There are no known specific conservation measures currently in place for Brookesia micra. However, all Brookesia species are protected under Appendix II of the Convention on International Trade in Endangered Species (CITES), meaning that any international trade in these chameleons should be carefully controlled ^{(2) (3)}.

Find out more about Brookesia micra:

• New Scientist: Zoologger - Itsy bitsy teeny weeny chameleons:
  http://www.newscientist.com/article/dn21478-zoologger-itsy-bitsy-teeny-weeny-chameleons.html
• BBC Nature - Tiny lizards found in Madagascar:
  http://www.bbc.co.uk/nature/17028940
• The Huffington Post - Tiniest chameleon, Brookesia micra, discovered on Madagascar island:
  http://www.huffingtonpost.com/2012/02/15/tiniest-chameleon-madagascar-brookesia-micra_n_1280151.html

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

Endemic

A species or taxonomic group that is only found in one particular country or geographic area.

Genus

A category used in taxonomy, which is below ‘family’ and above ‘species’. A genus tends to contain species that have characteristics in common. The genus forms the first part of a ‘binomial’ Latin species name; the second part is the specific name.

1. Glaw, F., Köhler. J., Townsend, T. and Vences, M. (2012) Rivaling the world’s smallest reptiles: discovery of miniaturized and microendemic new species of leaf chameleons (Brookesia) from northern Madagascar. PLoS One, 7(2): 1-24
2. CITES (January, 2013)
   http://www.cites.org/
3. Carpenter, A.I. and Robson, O. (2005) A review of the endemic chameleon genus Brookesia from Madagascar, and the rationale for its listing on CITES Appendix II. Oryx, 39(4): 375-380.
4. Mustain, A. (2012) World’s tiniest chameleon discovered. Our Amazing Planet, 14 February. Available at:
   http://www.ouramazingplanet.com/2440-world-tiniest-chameleon-discovered.html
5. Davies, E. (2012) Tiny lizards found in Madagascar. BBC Nature, 15 February. Available at:
   http://www.bbc.co.uk/nature/17028940
6. Zukerman, W. (2012) Zoologger: Itsy bitsy teeny weeny chameleons. New Scientist, 15 February. Available at:
   http://www.newscientist.com/article/dn21478-zoologger-itsy-bitsy-teeny-weeny-chameleons.html
7. Than, K. (2012) Pictures: Miniature chameleons discovered - fit on match tip. National Geographic Daily News, 15 February. Available at:
   http://news.nationalgeographic.co.uk/news/2012/02/pictures/120215-smallest-chameleons-new-species-madagascar-science/