Seed dispersal potential of jackals and foxes in semi-arid habitats of South Africa

Abstract

We determined the consumption of fruits and estimated potential seed dispersal of a canid community in semi-arid ecosystems of South Africa by comparing diets, defecation sites, densities and potential seed shadows of cape foxes (Vulpes chama), bat-eared foxes (Otocyon megalotis) and black-backed jackals (Canis mesomelas) on Benfontein and Rooipoort nature reserves. On Benfontein, all canid species consumed the fruit of Diospyros lycioides throughout the year. Jackals, but neither fox species, consumed relatively large amounts of Prosopis spp. (mesquite), an alien invasive. On Rooipoort, jackals had relatively high consumption of Ziziphus mucronata, followed by Grewia flava and D. lycioides. Bat-eared foxes had high consumption of fruit per area, although their seed dispersal potential was low due to their small potential seed shadow and poor germination sites. Cape foxes had the largest potential seed shadow, but their seed dispersal potential was low because of low fruit consumption, low density, and poor germination sites. Jackals had the highest seed dispersal potential because they consumed the most fruit species, had moderate densities, a relatively large potential seed shadow, and mostly good germination sites. We conclude that seed dispersal potential of South African canids, especially jackals, is more significant than previously known.