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The response of agamid lizards to rainforest fragmentation in the southern Western Ghats, India
N.M Ishwar, Ravi Chellam, Ajith Kumar and B.R. Noon

We examine the response of agamid lizards to the fragmentation of their rainforest habitat in the Western Ghats mountains in southern India. The data come from eighteen transects in nearly 400 sq. km of relatively undisturbed and continuous rainforests in the Kalakad–Mundanthurai Tiger Reserve (KMTR), and thirty-three transects in fourteen rainforest fragments (less than 1 ha to 2,500 ha) in the Anaimalai Hills, which were sampled during 1997–2000. A total of 263 agamid lizards belonging to eight species were recorded in the KMTR and 443 agamid lizards belonging to five species were recorded in the Anaimalai Hills. In the KMTR species richness showed a unimodal distribution with altitude, while the encounter rate showed a sharp linear decline due to the decrease in two most common species, Draco dussumieri and Calotes ellioti. Transects in forest fragments at lower elevations (700–1200 m) had lower species richness and encounter rates than the KMTR. Comparison of these forest fragments amongst themselves and with the KMTR showed a decline in the abundance of D. dussumieri C. nemericola and C. grandisquamis in the smaller fragments. Their encounter rates in the forest fragments, however, were better correlated with habitat features that represented the structural characteristics of the undisturbed forest (higher canopy height, greater canopy cover and the presence of more buttressed trees) than with the area of the fragment. The most common species in the forest fragments, C. ellioti, was unaffected by habitat fragmentation. C. rouxii has benefited from the fragmentation of these forests and has intruded into the smaller...