In areas of Bird Island with yellow crazy ants, ant dominance of the ground
invertebrate community went together with low arthropod diversity indices. However,
if all ants were excluded, the difference in mean diversity index between
islands was not significant, suggesting that the overall effect of ants on the
numerical characteristics of community structure was minimal. However, the
presence of Anoplolepis influenced the taxonomic composition of the community;
most notably, Crustacea (amphipods and isopods) were almost absent in Anoplolepis-
infested areas, reflecting the documented adverse effect of yellow crazy ants
on larger decapod Crustacea (Feare 1999b; Green et al. 1999). The Dermaptera,
which form an important part of pitfall trap assemblages on most islands of the
granitic Seychelles (Hill 2001), were also absent where Anoplolepis occurred.