Scientists have discovered four new species of super-tiny chameleons in Madagascar, according to a new paper in PLoS ONE. The smallest of the new species, Brookesia micra, is found only on the small island of Nosy Hara and has been dubbed the smallest chameleon in the world, measuring from nose to tail 29 millimeters (1.14 inches) at its largest. Scientists believe it represents a notable example of island dwarfism.
"The extremely small size of Brookesia micra could represent a 'double' island dwarf effect. In this scenario, Madagascar as a large island led to the evolution of the Brookesia minima group whereas the [...] islet Nosy Hara, might have favored the extreme miniaturization found in Brookesia micra," the researchers write. However they note it is also possible, given the shallowness of the sea between Nosy Hara and Madagascar, that populations of Brookesia micra survive on the mother island.
With these four new species, scientists have catalogued 26 Brookesia chameleons in all. These chameleons, which are endemic to Madagascar, inhabit the leaf litter during the day, but move up into the trees at night to sleep, a time when it becomes relatively easier for scientists to find them. On catching individuals, researchers used genetic analysis to determine species. The analysis revealed that many of these species are separated by millions of years, representing an ancient lineage of reptiles.
"The extreme miniaturization of these dwarf reptiles might be accompanied by numerous specializations of the body plan, and this constitutes a promising field for future research." says co-author, Frank Glaw with the Zoological State Collection of Munich, in a press release. "But most urgent is to focus conservation efforts on these and other microendemic species in Madagascar which are heavily threatened by deforestation."
With extremely small ranges, these chameleons are gravely imperiled by habitat loss. One of the new species was named Brookesia desperata for "desperate". Although the species was found in a protected area, the Forêt d'Ambre Special Reserve, researchers fear it may be close to extinction.
"Its habitat is in truth barely protected and subject to numerous human-induced environmental problems resulting in severe habitat destruction, thus threatening the survival of the species," they write.
Another of the new species may be even worse off: Brookesia tristis, meaning "sorrowful."
"The entire known range of this species (Montagne des Français) suffers from severe deforestation and habitat destruction despite recently being declared as a nature reserve," the researchers write.
Madagascar suffers from a booming population and severe poverty, putting massive pressure on its remaining forests and unique wildlife, including over a hundred species of lemurs. Worsening matters, the country recently suffered a logging crisis. Following a government coup in 2009, many of the nation's parks were beset by illegal rosewood logging urged by foreign traders. Raw rosewood often made its way to China where it was made into high-end luxury furniture.
CITATION:Glaw F, Köhler J, Townsend TM, 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): e31314. doi:10.1371/journal.pone.0031314.
