This study is conducted within the Bardia National Park, Nepal to assess the top-town and bottom-up control of tiger prey (deer). A vertical camera trap network comprising 50 units with a 1.5 km * 1.5 km grid size has been deployed since 2022 and ended in July 2024. These camera traps were distributed across the Karnali flood plain of BNP to cover different habitats (Shorea forests, riverine grasslands, riverine forests, mixed forests and grassland).  These hyper fire cameras employed passive infrared motion detectors and night time infrared illuminators, positioned at a height of 7/8 meters in trees, the cameras provide an image of 15 m² by facing downwards. Additionally, temperature and humidity loggers were integrated into 10-12 cameras within the existing network of 50. These loggers recorded data pertaining to black-globe temperature, ambient temperature, and relative humidity. Regular monitoring of cameras was conducted at every month.  Similarly, a local weather station is established in BNP to measure the local temperature, rainfall and relative humidity. Local weather data is also collected from the Chisapani weather station of Department of Hydrology and Meteorology (DHM). Additionally, GPS collar of spotted deer is planned for November-December.

Moreover, data from horizontal camera traps of Bardia National Park utilized in the National Tiger Survey of 2018 and 2022 is taken from department of National Parks and Wildlife Conservation (DNPWC), Nepal to understand the distribution and habitat use of tigers. The survey employed a grid of 418 units, each measuring 2 km * 2 km, for camera trap placement. For each station, a pair of cameras were stationed facing each other at a height of 45 cm above the ground, typically on trees or posts flanking forest trails or roads. The distance between the two cameras ranged from 6-8 meters, and a standard sampling period of 15 days was maintained for cameras within each grid.

The camera traps photos are processed using CamtrapR Package.  Analysis of activity pattern is started. Activity pattern of tiger and deer is calculated using kernel density estimates of activity patterns with overlaps package in which activity levels are plotted against time of the day, month and season to depict the activity patterns of each species. The same vertical and horizontal camera network are using for understanding the interactions between deer, tiger and humans.

During the field work period, coordination and collaboration has been done with Department of National Parks and Wildlife Conservation (DNPWC), Kathmandu and Bardia National Park Office, Bardia, Nepal, ational Trust for Nature Conservation (NTNC), Khumaltar, Lalitpur, NTNC, Bardia Conservation Program, Bardia, WWF Nepal and ZSL Nepal.