Understanding effect of anthropogenic factors on movement
We used the Brownian Bridge Movement Model, BBMM (Bullard, 1999) to
evaluate home ranges of all species. BBMM is a widely used method that
estimates the path of an animal’s movement probabilistically from data
recorded at brief intervals. BBMM quantifies the utilization
distribution of an animal based on movement paths, accounts for temporal
autocorrelation, and high data volumes (Fischer et al., 2013). The model
approximates the movement path between two subsequent locations by
applying a conditional random walk. We quantified BBMM at 50% and 95%
contours using ArcMET extension tool (Wall, 2014) in ArcGIS 10.2. We
considered 95% BBMM as the overall home range and 50% BBMM as core
area of the animal home range (Fischer et al., 2013).
Anthropogenic factors such as human population density, land use land
cover and road network have an adverse effect on animal movement through
fragmented and disturbed habitats (Tucker et al., 2018). We estimated
the human population density, land use land cover proportion and road
network within the home range of large carnivores. We used the human
population density map (100m resolution) available on the open source
website (http://www.worldpop.org.uk/; Steven, Gaughan, Linard, &
Tatem 2015). The land use land cover data of 1:25000 scale was acquired
from Bhuvan’s open source website (http://bhuvan.nrsc.gov.in/;
NRSA, 2016). The LULC maps were generated using “Resourcesat AWiFS”
satellite imagery, which classified Maharashtra into 13 land use
classes. These original classes were re-classified into five major
classes for analysis (Table 2). The road network data was obtained using
Open Street Maps (Openstreetmap, 2018). We considered primary and
secondary roads for our assessment because of their significant impact
on the movement of animals owing to higher traffic volumes.