Distribution of Pygmy hippopotamus (Choeropsis liberiensis) in Taï National Park, Ivory Coast: Influences of natural and anthropogenic factors

Abstract

The pygmy hippopotamus is an endangered species which receives little attention from the scientific community, especially wild populations. The highest density of wild pygmy hippopotamus is found in the Taï National Park in Ivory Coast which is inscribed on United Nations Educational, Scientific and Cultural Organization’s World Heritage list. Tai National Park experiences significant anthropogenic pressure from agricultural expansion, threatening pygmy hippopotamus due to habitat loss. To date, we have little information on the distribution of pygmy hippopotamus in the park. Therefore, the present study aims to determine the distribution of the species, emphasize the influence of the most dominant environmental factors and to present a model to predict areas of the Tai National Park supporting a pygmy hippopotamus population. We used a line transect method to make indirect observations through presence indices because of cryptic behavior of the pygmy hippopotamus. All indirect observations were combined with geographic information system and maximum entropy approach to species distribution modeling. Establishing the distribution of pygmy hippopotamus in the park has been established. Anthropogenic factors related to poaching and natural factors related to the river system and high altitudes were identified as the main factors influencing hippopotamus distribution. This work will help develop appropriate methods of monitoring this species, which requires further scientific studies to build a strategy for its protection.