Unravelling the Scale of Effect for the Mammals Inhabiting Tropical Deciduous Forests in Ramnagar Forest Division, Uttarakhand, India

The spatial scale at which landscape variables are measured strongly influences the species-landscape relationship. Therefore, identification of the spatial extent with the strongest landscape-biological response relationship, i.e., "scale of effect", is vital to appropriately assess the influence of landscape variables on the biological response of species. Here, we have investigated the scale of effect for six mammals, viz., tiger (Panthera tigris), nilgai (Boselaphus tragocamelus), sambar (Rusa unicolor), Tarai gray langur (Semnopithecus hector), rhesus macaque (Macaca mulatta), and Indian crested porcupine (Hystrix indica) inhabiting Ramnagar Forest Division, Uttarakhand, India. In the present study, camera traps were deployed at 54 sites to determine presence of species and landscape diversity around each site was evaluated at six spatial scales (0.25 km to 2.5 km) using a Landsat 8 imagery. Univariate generalized linear models with binomial (logit link) and Poisson distribution were performed to determine the scale of effect for each species and guild, respectively. We found scale of effect for a species group/guild typically matches the average scale of its responsive species to landscape diversity. It is independent of a species' trophic position but influenced by mobility along with specialisation. Our findings confirm that more mobile generalists have a greater scale of effect.