Habitat Use of Warthogs on a Former Cattle Ranch in Tanzania

Abstract

We investigated habitat use of the common warthog (Phacochoerus africanus) on a large, recently abandoned ranch in Tanzania. Fifty years of ranching had heavily modified the savanna vegetation, especially close to the paddocks where cattle were kept overnight. We recognized 4 characteristic vegetation zones along transects radiating from these paddocks: paddock center (PC), paddock margin (PM), acacia scrub (AS), and unmodified savanna (SV). Within these zones, we recorded warthog traces such as footprints, dung pellet groups, and diggings, and used these data to calculate presence and activity indices. Warthog traces were more abundant in the PM and AS than in PC and SV zones, and during dry periods the presence and activity indices were highest within and close to paddocks. From our results, we concluded that 1) warthogs are pioneer species, being one of the first native ungulates to recolonize cattle-impacted savanna vegetation; 2) areas close to former paddocks are particularly attractive to this species because of their vegetation structure and nutritional quality; 3) management to restore wildlife populations in former rangeland should initially focus on those areas where wildlife recolonization commences; and 4) indirect observations help to identify habitat-use patterns and point out key wildlife areas important for future protection.