Physiological stress responses of tigers due to anthropogenic disturbance especially tourism in two central Indian tiger reserves.

Sagar Kittur,Abhinav Tyagi,Andre Ganswindt,Mahender Reddy,Sergey Naidenko,Govindhaswamy Umapathy,Vinod Kumar,Amy Newman

doi:10.1093/conphys/coz045

Abstract

Tigers continue to face unprecedented threats to their existence due to poaching, habitat loss, habitat fragmentation and anthropogenic disturbances. The present study examines the physiological stress response of tigers due to anthropogenic activities including wildlife tourism in Bandhavgarh Tiger Reserve and Kanha Tiger Reserve using faecal glucocorticoid metabolite (fGCM) measurement. We collected a total of 341 faecal samples from both reserves during tourism and non-tourism periods. Data on various anthropogenic disturbances including tourism activities like number of vehicles and visitors were also collected. We ascertained the species identity and sex of all the samples collected using genetic markers. fGCMs were extracted using a previously reported procedure, and fGCM concentrations were subsequently determined using an established enzyme immunoassay. There was no significant difference in overall mean fGCM concentrations between the two tiger reserves, but within each reserve, concentrations were significantly higher in tigers during the tourism period as compared to the non-tourism period. We also found that the number of tourist vehicles and disturbance level significantly correlated with fGCM concentrations. This study further supports the assumption that unbridled tourism associated with high anthropogenic disturbance can be related to perceived stress and consequently may have an impact on the reproductive fitness of tigers and long-term survival of isolated populations.

Highlights

Large carnivores are among the most threatened species of the world (Ripple et al, 2014), with especially felids experiencing a significant contraction from their historical range (Wolf and Ripple, 2017)
There was no significant difference in overall mean faecal glucocorticoid metabolite (fGCM) concentrations between the two tiger reserves, but within each reserve, concentrations were significantly higher in tigers during the tourism period as compared to the non-tourism period
This study examined the relationship between anthropogenic disturbance and physiological stress levels in two tiger populations in central India by assessing faecal glucocorticoid metabolite concentrations of individual tigers and the status of anthropogenic disturbance of the related reserves during tourism and non-tourism periods

Summary

Introduction

Large carnivores are among the most threatened species of the world (Ripple et al, 2014), with especially felids experiencing a significant contraction from their historical range (Wolf and Ripple, 2017) They play an important role in maintaining ecological balance as apex predators (Terborgh et al, 2001) and are under severe threat due to habitat fragmentation, habitat loss and isolation, reduction in genetic diversity, prey depletion and poaching (Morell, 2007; Walston et al, 2010). Their biological traits, e.g. solitary life, and large individual home ranges render them vulnerable to threats associated with increasing human population densities (Cardillo et al, 2004). The outcome of these efforts has led to the identification of ‘Tiger Conservation Landscapes’, which include interconnected PAs by corridors that could potentially support viable populations (Dinerstein et al, 2007; Sanderson et al, 2010; Joshi et al, 2013)

Methods

Results

Conclusion