Regionally unique ant assemblages associated with community-based conservation in northwestern Ghana

Abstract

Community-based conservation can play an important role in preserving biodiversity, but it is unclear whether such benefits extend to invertebrate communities; in particular, baseline data for insect communities is lacking to assess efficacy of conservation efforts. Here we evaluate ant assemblages across three habitats, protected within the Wechiau Community Hippo Sanctuary (WCHS) in the Upper West Region of Ghana. We compare relative ant species diversity and uniqueness between the sanctuary's Guinea savannah, riparian forest, and floodplain habitats. Ants were collected with other invertebrates using malaise traps, pitfall traps, and yellow pan traps between 2001 and 2011 multiple times per year. From these data, we compiled a list of ant species found, castes collected, and functional groups, and evaluated the differences in ant diversity among the habitats using accumulation curves, assemblage structure comparison, and Morisita-Horn indices. We also compared the overall WCHS assemblage to other ant assemblages in Western Africa to gain a clearer understanding of relative diversity and uniqueness. We collected 83 species from seven subfamilies and 44 genera; 14 of the species were previously unrecorded in Ghana, including one ant species new to science. Ant species diversity differed among habitats in assemblage composition but not significantly in species richness. We found that the WCHS ant assemblage was relatively unique, sharing only about 35% of species found in similar Côte d'Ivoire habitats, and 25% of other Ghanaian assemblages. Some species present in the WCHS were not found in any of the other compared assemblages. We conclude that community-based conservation initiatives like the WCHS may play an important role in conserving the biodiversity of ants.