Effects of visitor disturbance on tetrapod vertebrates in the Horton Plains National Park, Sri Lanka

Abstract

Effect of visitor disturbances on tetrapod vertebrates was studied from December 2017 to October 2018 in the Horton Plains National Park (HPNP), which is one of the world’s best nature reserves and a popular tourist destination of Sri Lanka. Roads and nature trails with cloud forest, aquatic and grasslands habitats inside the HPNP were selected to compare the effect of visitor disturbances. Three 100 meter fixed length line transects were marked along the roads and the nature trails in each habitat. Vehicle noise was measured using sound meter software. Visitor activities that cause disturbance included road kills, photography, trampling and animal feeding. Amphibian and reptile road kills were higher compared to other tetrapod road kills during vacation periods. Behavioral response of species to visitor disturbances included avoidance, habituation and attraction. When the vehicle noise range was from 63±2.11 dB to 69±2.11 dB, habituation behavior was displayed. When the vehicle noise range increased to the range of 70±4.71 dB to 88±4.71 dB, avoidance behavior was displayed. Animals display a propensity to habituation behavior compared to avoidance behavior when vehicle speed was less than 30 kmh/hr. The results of this study can be used to integrate with the future visitor, park and wildlife management practices of the park.