LB 12-119 - Distributional Response of Tiger Prey Species along the Gradient of Human Disturbance and Management Regime

Thursday, August 10, 2023

5:00 PM – 6:30 PM PDT

Location: ESA Exhibit Hall

Presenting Author(s)

NK

Naresh Khanal, n/a

Graduate Student
Michigan State University
Kathmandu, Nepal

Coauthor(s)

NG

Narayan Gautam

Professor
Tribhuvan University, Nepal
GK

Gopal Khanal

Graduate Student
University of British Columbia, Nepal

Conservation of endangered species like Panthera tigris and achieving the goal of doubling the tiger population by 2022 requires the recovery of prey populations. Therefore, knowledge of prey populations and their distributional response along the human disturbance gradient is important in guiding tiger conservation efforts.The main objective of this study was to assess the impact of human disturbance, habitat type, and management regime on the relative abundance of key prey species of tiger in Bardia National Park, its buffer zone, and the Khata Corridor area.We conducted sign surveys along 1 km transects in a total of 126 transects in 32 grids of each 9 km2, and recorded signs of each species for each transect and evidence of human presence, livestock grazing, and habitat type. The total survey area was 288 km2. First, we compared whether the sign encounter rate of each species differs according to the habitat type and management regime. We then fit Generalized Linear Models (GLM) to test the influence of predictor variables on the Relative Abundance Index (RAI) or sign encounter rate per km of prey species.Chital was found to have the highest RAI (RAI=1.74, SD 1.96) whereas swamp deer had the lowest (RAI = 0.05, SD 0.31). Overall species encounter rate (SER) showed mixed results for habitat type, with some species preferring mixed forest (spotted deer 2.40 SER, wild boar 1.90 SER) while some preferring grassland (hog deer 1.38 SER). Similarly, the national park had the highest encounter rate for spotted deer, swamp deer, and sambar whereas wild boar, blue bull, and barking deer had the highest encounter rate outside the buffer zone area. GLM showed a consistent negative influence of human encounter rate (HER) and livestock grazing intensity (LGI) on the relative abundance of all species except wild boar and barking deer. Interestingly, both species had a positive association with HER but not with LGI.The results suggest that some species are highly vulnerable to human disturbance and other are to some extent resilient. Differential response to habitat type and management regime suggests that integrated management of all habitat types and management regimes would be necessary to sustain the collective prey base recovery of all species for tiger conservation. Moreover, the occurrence of some of the prey species in and outside the buffer zone area can be taken as an opportunity to include the local community in conservation activities formulating appropriate plans.