CHAMELEONS OF MADAGASCAR

Isolated since the Cretaceous, the island of Madagascar is famous for its unique flora and fauna. The land is rich in lizard species, with five families, Scincidae (skinks), Gekkonidae (geckos), Gerrhosauridae (plated lizards), Opluridae (Madagascan iguanas) and, most iconically, Chamaeleonidae (chameleons) represented. Probably no lizard family is more specialized than this last group of mostly arboreal reptiles. Extreme lateral body compression and a slow, rocking gait make a chameleon look like a leaf waving in the wind—practically invisible to predator and prey alike, and when seriously threatened by the former, that flattened body can be oriented away from the threat to effectively hide the lizard behind its perch. A powerful prehensile tail and fused toes that function like tongs provide a strong and effortless grasp among small branches, and a unique arrangement of shoulder and hip joints supports their mass for long periods at the expense of little energy. Turret-shaped eyes swivel independently of each other, giving their bearer a wide field of stereoscopic vision without sacrificing nearly 360º of peripheral sight. Many of these adaptations appear to a lesser degree in some other arboreal lizards, particularly in the unrelated American family Polychrotidae, which includes the well known anoles (Anolis spp.) and the Cuban False Chameleons (Chamaeleolis spp.). Chameleons have taken the common lizard habit of capturing prey with a tongue-flick to the extreme, accurately snagging prey from as much as a snout-to-tail length away. Their color changing skills are legendary, but, contrary to popular belief, are used mostly as social signals and thermoregulation aids rather than devices of camouflage. Chameleons probably evolved on the mainland (the earliest known fossils are from Miocene Europe), and were transported to the island on floating detritus. They thrived in their new digs, and today about half of all known chameleon species hail from Madagascar or nearby islands.

My first experience with a Madagascan chameleon was on the second day of my first visit to the island, in 1994. In a bare tree, in a small town in the Sakalava region west of the capital, Antananarivo, I noticed a large lizard, nearly two thirds of a meter in length, that reminded me of an American iguana. As I approached, he tried to hide behind his perch, (above, top), but his mass refused to be concealed. This was an Oustalet's Chameleon (Furcifer oustaleti), a species that can exceed 680mm in length, longer than any other member of the family. Long and lean, it's an active species whose tongue can snatch small reptiles, mammals and birds along with large insects. In the trees it moves in typical chameleon fashion, but on the ground it can run like a normal lizard (above, lower). It's the only chameleon species I've seen move like this. F. oustaleti is one of the few lucky Madagascan creatures that seems to thrive on deforested land, and its numbers and range continue to swell as the island is degraded.


Another large Furcifer species, the well-known Panther Chameleon (F. pardalis) also finds benefit in deforestation. It is found throughout the island, and on a number of small neighboring islands. One of the most variable chameleon species, its colors range the spectrum, from nearly pure blue individuals on the island of Nosy Bé to the spectacular wine-colored males of Nosy Mangabé (above, right and in the painting below).


The Minor Chameleon (F. minor - above) is one of the smaller members of this, the largest Madagascan chameleon genus. The 120mm female (left) is about two-thirds the length of her mate, who bears a masculine bifurcular nose appendage. Unlike most chameleons, his skin colors are more somber than the female's. The pattern sported by the female in the painting displays her unwillingness to mate.


The photographs above show a few other Furcifer spp.

Calumma is the other genus of large Madagascan chameleons. It includes the massive Parson’s Chameleon (C. parsoni - above), which outweighs the Oustalet’s, if not reaching a total length as great, and numerous others, including the diminutive C. nasuta (below, right), which only slightly exceeds 100mm.


The smallest Madagascan chameleons belong to the genus Brookesia. The largest of these is the spectacular little 80mm B. perarmata, which looks like a tiny version of the rugged karst country of the southwestern edge of the Central Plateau, which it calls home. At the other end of the spectrum lays the B. minima complex, which includes B. peyrierasi (above, lower-left), which are among the smallest of all terrestrial vertebrates—only the Mlanje Mountain Chameleon (Nadzikambia mlanjense) of Malawi is smaller. This photograph shows an individual that we found on Nosy Mangabé. As I held a torch-beam on the lizard and prepared to photograph it on my friend’s hand, a seemingly monstrous fly lit beside it as if sensing the need for scale reference. These tiny reptiles walk about the forest floor, popping off springtails and other minute invertebrates with their tongues. At night they prefer an elevated perch, and will climb a few centimeters up a grass stem to spend the night.
Habitat loss and illegal collection has negatively impacted a number of species, but unlike most Madagascan taxa, no Madagascan chameleon appears to be in serious trouble so far. The I.U.C.N. considers Brookesia perarmata, Furcifer campani, F. labordi and F. minor vulnerable. It appears that the latter species might be another of the lucky ones benefiting from deforestation. Perhaps this can be attributed to a reduction of predators.
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PAINTINGS:
upper: SPRAWL--OUSTALET'S CHAMELEON (2007) acrylic 18" a 24"
center: RUFFED LEMUR & PANTHER CHAMELEON (2007) acrylicx 18" x 24"
lower: MINOR CHAMELEONS (1998) acrylic diptych 10" x 8"; 10" x 8"
all photographs taken by CPBvK at various times, in various locations on Madagascar