Order: Squamata - Lizards and Snakes
Phylum: Chordata - Vertebrates
Red List status: Not listed
Snout-vent length: 265 mm 101 mm
Total length: 565 mm 213 mm
Restricted to Madagascar, where it is widely distributed throughout the west of the island and the dry south. Records from Réunion are erroneous, and some Malagasy records are unconfirmed.
A very large chameleon, similar in most respects to its close relative Oustalet's chameleon. In common with this species, the warty chameleon has a high casque with a pronounced parietal crest. Rostral crests are present and extend to the snout tip, but do not connect. A lateral crest is present but is poorly-developed. The ventral crest is very poorly-developed. The gular crest consists of 15-20 cone-shaped scales. The warty chameleon's common name derives from the row of enlarged scales, up to 3 mm in diameter, along the midline of the flank, in contrast to the smaller scales that cover most of the body. This gives the animal a warty appearance and an uneven texture. This feature may be shared with some individuals of Furcifer oustaleti.
As with the larger species, the warty chameleon is most easily distinguished from its relatives by characteristics of the dorsal crest, which in males of this species conissts of less than 40 long (up to 4 mm), distinct spines. Females lack a complete dorsal crest; instead, there is a short row of tall spines just behind the head, and a row of tubercles down the back.
Colouration is normally grey to brown in both sexes; a thick white line is present along the midline of the flank, interrupted by irregular dark-edged spots. No mid-ventral line is present. Males can be reliably distinguished from females by characteristics of the dorsal crest; additionally, size dimorphism is pronounced with females being considerably smaller, and males may sometimes exhibit vivid green colouration on the lower flanks, limbs and tail (females are grey or whitish).
Similar species: The warty chameleon lacks a rostral appendage, distinguishing it from the similarly-sized Parson's chameleon and from Furcifer antimena, which also has a white flank stripe and tall spines. Colouration and the presence of spines either along the back or behind the head distinguish it from the white-lined chameleon, as does its much larger adult size and absence of a mid-ventral stripe. The length and number of spines in the dorsal crest distinguish the warty chameleon from F. oustaleti and F. nicosiai; the latter has a crest of 50-60 small spines in the male, and no spines but a short row of 8 tubercles behind the head in the female.
The warty chameleon appears to have more restrictive habitat requirements than Oustalet's chameleon, being associated primarily with dry, typically disturbed habitats. In these areas, however, it commonly co-occurs with its larger relative. Occasional records have been taken from primary rainforest, and the species' range does extend into the southern part of Madagascar's rainforest belt.
Anecdotally, the warty chameleon is more arboreal than F. oustaleti, with even large specimens most commonly encountered in trees to heights of one or two metres (personal observation).
Animals in arid areas of southern Madagascar have been recorded sheltering in sandy burrows during the dry season, a time when their surface activity is much reduced (D'Cruze et al, 2009).
Clutch size: Clutches consist of up to 45 eggs.
Life cycle: The incubation period may be as much as 9 months; newly-hatched adults reach maturity in a further 9-12 months.
The subspecies F. v. semicristatus is recognised from the southern tip of the island. However, the taxonomy of this entire species group is uncertain (see the entry under F. oustaleti), and requires "further study" (Glaw & Vences, 2007).
D'Cruze, N., Olsonn, A., Henson, D., Kumar, S. and Emmett, D. (2009) The amphibians and reptiles of the lower Onilahy river valley, a temporary protected area in southwest Madagascar. Herpetological Conservation and Biology 4: 62-79
Glaw, F. and Vences, M. (2007) A Field Guide to the Amphibians and Reptiles of Madagascar. Third Edition. Cologne, Vences & Glaw Verlag: 496pp