The reptile fauna of Madagascar is extremely diverse and characterized by a high degree of endemism. The international demand by specialist reptile hobbyists, principally in Europe and North America, for chamaeleons (Calumma spp and Furcifer spp) and day geckoes (Phelsuma spp) has stimulated an extensive export industry in these species. This industry has evolved without adequate controls to regulate the number of participating operators, the numbers of specimens harvested from the wild for export and little thought given as to the long-term sustainability of the industry. Furthermore, the impact of the trade on the variety of species and numbers of specimens involved has not been subject to any scientific scrutiny or regulation. As such, the sustainability of harvest regimes for most species is largely unknown.

The taxonomy of chameleons and day geckoes has been the subject of active research in recent years. In addition to including several new taxa, the experimental management programme has adopted the currently accepted nomenclature. In addition to adopting the use of the genera Calumma and Furcifer, the names of several taxa have been changed as a result of more precise taxonomy. Glaw and Vences (1994) note that about 50 percent of all known chameleon species in the world (57 of 131) occur in Madagascar, including the largest species, Furcifer oustaleti (TL -685mm) and the smallest, Brookesia minima (TL -34mm). Malagasy chameleons are classified into two subfamilies - Brookesiinae and Chamaeleoniinae.

The subfamily Brookesiinae includes the ground and dwarf chameleons in the genus Brookesia. These lizards are generally small, (30-110mm total length) with brownish colouration. Twenty-two species are recorded endemic to Madagascar (Glaw and Vences, 1994). The Chamaeleoniinae contains the true chameleons and comprises two genera Furcifer (17 species) and Calumma (18 species). The Chamaeleoninae are large, sexually dimorphic, dichromatic lizards with the ability to change colour over short periods to imitate the general colour of their background.

All Malagasy chamaeleonid lizards were previously classified, on the basis of presence or absence of occipital lobes and the condition of the rostral appendages and the casque, into ten species groupings in the single genus Chamaeleo. More recently, Klaver and Böhme (1986) reviewed the phylogeny of the Chamaeleoniinae and demonstrated, on the basis of hemipenis morphology, that the Malagasy species comprised two genera - Furcifer and Calumma. The genus Calumma includes all the species with occipital lobes. Nasal appendages are present in males (except C. gastroteania and C. peyrierasi). Calumma spp tend to be smaller than Furcifer spp, although adult males of C. parsonii can attain a total length of 600mm.

Calumma spp are the typically rainforest chameleons and occur in humid areas in the east and north of Madagascar. Calumma spp are the only chameleons that inhabit the high and cold mountain summits to 1900 metres (Glaw and Vences 1994). Furcifer spp are distributed principally in the arid regions of western Madagascar. Many Furcifer spp are able to adapt to degraded habitats and occur in a wide variety of environments in the west, central highlands and in the east (e.g. F. lateralis and F. oustaleti). However, some species (e.g. F. willsii, F. balteatus and F. bifidus) are restricted to rainforest habitats (Glaw and Vences, 1994).

Day geckoes of the genus Phelsuma comprise 36 species with numerous subspecies (Glaw and Vences, 1994). Phelsuma spp are widely distributed on many islands in the west Indian Ocean (Madagascar, Comores, Seychelles, Reunion, Mauritius, Pemba and the Andaman Islands) and the east coast of Africa (Zanzibar, Tanzania). Madagascar is the centre of radiation where twenty-two species are known to occur, of which eighteen are endemic.