Bhutan Journal of Natural Resources and Development

Prey Occupancy and Functional Connectivity in Biological Corridor Seven, Bhutan

Jigme Thinley — 2025-12-31

Biological corridors with a healthy prey base support predator dispersal, yet studies that combine occupancy and connectivity remain limited. This study evaluates six ungulate prey species in Biological Corridor Seven, Bhutan. Thirty-one paired camera traps deployed on a 3 × 3 km grid from January to July 2025 yielded 5,144 trap days and 822 independent events. A hierarchical Bayesian multi-species occupancy model was fitted in PyMC (v5) to estimate occupancy (ψ) and detection probability (p) across winter, spring and summer. Predicted occupancy was mapped to a 500 × 500 m grid (1,689 cells) and analysed with random-walk connectivity (gdistance, R) to identify movement routes and pinch points. Generalists showed high and widespread occupancy (ψ = 0.933–0.981), with peak detectability in winter (p = 0.185–0.320). In contrast, specialists were concentrated in narrow upper-elevation areas (ψ = 0.639–0.877), peaking in spring (p = 0.085–0.164). Connectivity analysis isolated seven macro pinch points and numerous conflict segments (< 500 m long) where linear infrastructure is likely to restrict movement. Priority mitigation includes vegetated overpasses on dry slopes and bridge-style underpasses or culverts at riparian conflicts. A tiger Panthera tigris recorded at two locations confirms the use of corridor by apex predator. This integrated occupancy–connectivity framework provides a reproducible basis for prioritising mitigation and guiding adaptive corridor management under growing infrastructure development and climate pressure.

An Extended Distribution Record of Paphiopedilum fairrieanum (Lindl.) Stein (Orchidaceae: Cypripedioideae) in Bhutan

Phuntsho Wangdi — 2025-12-31

In this Note, an extended distribution record of Paphiopedilum fairrieanum (Lindl.) Stein (Orchidaceae: Cypripedioideae) in Bhutan is provided. The new occurrence habitat of this orchid was recorded from Gangtho, Tsamang under Mongar District in the eastern part of Bhutan.

Surgical Correction of Patent Urachus in a Female Calf: A Case Report

Rinchen Tshering — 2025-12-31

Patent urachus in calves is a congenital or acquired condition where the embryonic tube connecting urinary bladder to umbilicus fails to close after birth, causing urine to dribble from the navel. The study describes the anaesthetic protocol and surgical procedure for correction of patent urachus. The anaesthetic protocol was premedication with 0.2 mg kg-1 xylazine, induction and maintenance on 5.0 mg kg-1 ketamine with local infiltration of 5 mg kg-1 lignocaine. The procedure involved an elliptical incision around the umbilicus, followed by sharp dissection of subcutaneous tissues to expose and isolate urachus. Transfixation ligature was applied to urachus before transection and the urachal stump was sutured using simple continuous pattern. This study documents the successful surgical correction of patent urachus in a female calf.