Human activity, including tourism, increases stress and influences breeding location choice in wild tigers in India

Abstract

Wildlife tourism is increasing globally, with a growing proportion of activities occurring in protected areas that help them generate significant revenue. Consequently, management authorities must integrate tourism into conservation planning. Such rise in human activity in these areas can adversely affect wildlife behaviour, physiology, and reproduction. A better understanding of the impact of wildlife tourism on tiger wellbeing and spatial behaviour is therefore critical for the sustainable management of these populations. We studied the effects of wildlife tourism and anthropogenic activities on stress and reproductive physiology in wild tigers across five reserves in India. We quantified faecal glucocorticoid metabolites (fGCMs), a biomarker of stress, and faecal progesterone metabolites (fPMs), an indicator of breeding activity in females. We collected 728 presumptive tiger scat samples from core and buffer zones during both tourism and non-tourism seasons, which encompass breeding periods. Genetic analysis confirmed that 610 samples originated from tigers; these were sexed and analyzed for fGCM and fPM levels. Our findings indicate that tigers exhibited higher fGCM levels in areas with high anthropogenic activity. Further, we observed spatial variation in fGCM levels that correlated with patterns of human disturbance, including tourism, suggesting a heterogeneous distribution of stressors. As human disturbance intensified in core zones, tiger fGCM levels increased and were negatively correlated with proximity to tourism roads. Furthermore, among the areas surveyed, tigresses exhibited higher fPM levels in certain locations of the reserves, where they experienced lower fGCM levels compared to other locations. This may indicate that tigresses potentially choose locations with less disturbance for breeding. Based on these results, we discuss potential management strategies to mitigate the impact of human activities on tigers and support their reproduction.