SEXUAL DIMORPHISM AND REPRODUCTIVE BIOLOGY OF A SIkkIM ENDEMIC GRASS LIZARD TAkyDRoMus sIkkIMENsIs (SQUAMATA: LACERTIDAE) IN THE EASTERN HIMALAYA, INDIA

SEXUAL dimorphism is widespread among lizards and may cause variation in morphology or color between sexes. These variations are determined by ecological, environmental, and genetic factors. In this study, we India. We investigated whether differences exist in morphology and colors between sexes, and we also explored the breeding biology of this lizard in both captivity and under natural conditions. We observed female-biased sexual dimorphism in size and shape with females having greater snout vent length (SVL), forelimb length (FLL), hindlimb length (ILL), length of fourth finger (LFF), and snout to arm length (SAL) than males. Males had larger head length (IL) and head width (IW) compared to females. Our findings showed female-biased sexual dimorphism to fecundity selection, where larger females have higher fecundity than smaller females. Additionally, male-biased sexual dichromatism was observed during the breeding season. The primary habitat of Sikkim Grass Lizard in the study region is agro-ecosystems mostly below 1,000 m elevation. These ecosystems are undergoing rapid changes due to developmental projects, which could jeopardize the long-term survival of this species. Therefore, conservation efforts are needed and should focus on preserving a mosaic of agro-ecosystems, especially in the lower middle hills in Sikkim-Darjeeling region of the Eastern Himalaya.