Estimating Cape hare occupancy and abundance in southern Tunisia using spotlighting data

Abstract

This study outlines the importance of integrating spotlighting data and occupancy modelling to estimate the spatial occupancy, abundance and habitat preferences of Cape hares Lepus capensis in southern Tunisia. Exploring the spatial distribution pattern of this species is problematic because of its nocturnal and secretive behaviour. In order to overcome these constraints, we used spotlight surveys on equidistant points along tracks to collect presence/absence data. Using a likelihood-based approach, we estimated occupancy and relative abundance of Cape hare populations in three national parks: Sidi Toui, Bouhedma and Jbil. We also combined the three parks in a single area to represent ‘southern Tunisia’ for investigating the factors affecting its distribution pattern. Sidi Toui showed the highest occupancy and relative abundance values (88.84 ± 10.95% and 7.97 hares km−2, respectively). Bouhedma was also recognised as high-quality hare habitat with occupancy and relative abundance values of 61.70 ± 11.70% and 2.85 hares km−2, respectively. The lowest occupancy (49.65 ± 26.25%) and relative abundance (2.10 hares km−2) estimates were encountered in Jbil. The combined parks model suggested that part of the distribution pattern of Cape hares can be explained by habitat quality. Spatial occupancy over southern Tunisia showed a positive relationship between its occurrence and the availability of Poaceae and Plantaginaceae.

Keywords: Lepus capensis, occupancy, PRESENCE program, relative abundance, southern Tunisia national parks, spotlighting