Data from: Effects of tree plantations on population and roosting ecology of an endemic agamid lizard in Western Ghats Biodiversity Hotspot

We assessed the influence of tree plantations on population density and roosting ecology (roosting substrate and height) of Monilesaurus rouxii, an endemic agamid lizard, across low- and high-elevation forests and cashew and rubber plantations in the Western Ghats Biodiversity Hotspot using nocturnal transects. This dataset shows that low-elevation forests had significantly higher densities of Monilesaurus rouxii than high-elevation forests and cashew plantations. Roost site use did not differ significantly across the different land-use, indicating conserved roosting behaviour. However, Monilesaurus rouxii exhibited ontogenetic shifts in roosting substrate and height. Description of the data and file structure Species Coverage: Monilesaurus rouxii Geographic Coverage: Sindhudurg District of Maharashtra, India (15°40'–16°0'N; 73°51'–74°9'E) Temporal Coverage: June, July, August, September (2022). Field data was collected by Ninad Gosavi & Himanshu Lad More details about the data can be obtained from R. Naniwadekar from the Nature Conservation Foundation ([www.ncf-india.org](http://www.ncf-india.org)). File Descriptions: There are five files in this dataset: 1. dat_monilesaurus_night.csv2. dat_monilesaurus_night_adult.csv3. dat_monilesaurus_night_juvenile.csv4. dat_monilesaurus_height_roost.csv5. dat_monilesaurus_substrate_orientation.csv The first three datasets contain information from the night-time density surveys, in the distance sampling framework. Description of the columns corresponding to these: 1. Region.Label - Land-use class (Cashew, Primary_forest_high, Primary_forest_low, Rubber)2. Area - Size of the study area (set to 1)3. Sample.Label - Transect name4. Effort - Length of the transect measured with a measuring tape (in Km)5. Species_name - *Monilesaurus_rouxii* - study species6. size - Number of animals in group (all 1 in these data)7. distance - Perpendicular distance (m)8. Age - Age class (Adult/ Juvenile - Based on Snout-vent lengths - larger than 50 mm SVL as adults, and the rest as juveniles) The second two datasets contain information on roosting ecology. In both these datasets:1. Category - Land-use class (Cashew, Primary_forest_high, Primary_forest_low, Rubber)2. Age - Age class (Adult/ Juvenile - Based on Snout-vent lengths - larger than 50 mm SVL as adults, and the rest as juveniles) In the dataset "dat_monilesaurus_height_roost": 1. Height_from_ground - Height from ground (cm) In the dataset "dat_monilesaurus_substrate_orientation":1. habit - Roosting substrate [climber, shrub (leaf, stem, primary or secondary branches), grass (leaf), and tree (secondary branch)].2. orientation - Head position of roosting lizards (relative to the lizard’s orientation with respect to the trunk - ‘inward’ if the head faced towards the trunk, ‘outward’ if facing away from the trunk, ‘upward’ if the lizard was on the trunk with its head pointing upward, and ‘downward’ if it was on the trunk with its head pointing downward). Brief description of the survey and data: 31 line transects of variable lengths across the four land-use types (low- and high-elevation forests, cashew and rubber plantations) were established. Two observers (NG and HL) walked these transects in the night between 1830 - 2330 hr following the distance sampling survey methodology, and systematically searched for Monilesaurus rouxii lizards using rechargeable hand-held torches (luminous flux: at least 300 lumens). Whenever a roosting Monilesaurus rouxii was detected, the perpendicular distance of the animal from the transect and the height of the roosting animal from the ground using a rangefinder (Leica Geosystems D1 laser distance metre; range: 0.2–40 m; accuracy: ± 2 mm) was recorded. The head position of roosting lizards and the roosting substrate were also recorded. NA in the transect files correspond to transects where no animals were detected. See the preprint (https://doi.org/10.1101/2025.02.10.637441) for a detailed methodology. Funding: On the Edge Conservation Grant (UK)