Use of a biological corridor by a tiger Panthera tigris : evidence from a 2025 camera-trap survey in Bhutan

Biological corridors are designed to maintain connectivity among protected areas for wide-ranging mammals; however, evidence of their utilization in Bhutan is limited. In this study, we deployed 31 paired camera-trap stations across a 3 × 3 km grid of 47 grid cells during January–July 2025 (a total of 5,144 trap-nights) within the 419 km 2 Biological Corridor 7 that connects Wangchuck Centennial and Phrumsengla National Parks and Bumdeling Wildlife Sanctuary in north-east Bhutan. Nine photographs of a single adult male tiger Panthera tigris were obtained from two independent events in February 2025 at two stations (at 2,352 and 2,687 m altitude), 4 days apart. The stripe patterns did not match any individuals in national catalogues. Across all camera-trap stations, effort-standardized detections (events per 100 trap-nights) of key prey species (barking deer Muntiacus muntjak , sambar Rusa unicolor , and wild pig Sus scrofa ) were higher in late winter than in spring, and human and cattle detections at the two stations where the tiger was photographed were lower in winter than in spring. These records confirm tiger presence in Biological Corridor 7 but do not demonstrate corridor-wide functional connectivity or movement between protected areas. Repeated seasonal camera-trap surveys and non-invasive genetic sampling are required to assess long-term occupancy and gene flow.