Do Invasive Fire Ants Affect Habitat Selection within a Small Mammal Community?

Abstract

Animals must balance foraging with the need to avoid predators and risky habitats that decrease their fitness, and at the same time they must cope with competitors vying for habitat and resources. We examined how habitat selection and population density of four native small mammals were altered by the presence of red imported fire ants (Solenopsis invicta). When population size was low, hispid cotton rats (Sigmodon hispidus) and pigmy mice (Baiomys taylori) as well as white-footed mice (Peromyscus leucopus) used the "safe", low fire ant habitat, as predicted by theories of density-dependent habitat selection. However, as fire ant population sizes expanded, cotton rats appeared to displace pigmy mice into the fire ant-dense grassland drainage while white-footed mice (Peromyscus leucopus) displaced all the other small mammals from low fire ant forest/brushland habitat.

Decreased small mammal and on-host tick abundance in association with invasive red imported fire ants ( Solenopsis invicta )

“…predation) and indirect effects (e.g. changes in habitat selection and avoidance behaviour) [ 7 , 8 ]. Furthermore, we observed that increased small mammal populations on S. invicta -suppressed plots were associated with an increased abundance of on-host ticks ( figure 2 ), consistent with host population regulation of tick populations [ 14 ].…”

“…Ticks and small mammals transmit and maintain numerous zoonotic pathogens that are significant public health concerns. Solenopsis invicta are known to predate small mammals [ 6 ], and their presence is associated with changes in mammal foraging activity [ 7 ] and habitat selection [ 8 ] possibly mediated by changes in food resources [ 9 ]. Solenopsis invicta are also associated with reductions in tick populations [ 10 , 11 ], although effects vary between tick species [ 10 ].…”

Using the red‐imported fire ant to study invasive species removal and reinvasion

“…For instance, RIFA has been linked to decreases in native ant and invertebrate abundance and species richness in Texas and Mississippi (Epperson & Allen, 2010;Morrow et al, 2015;Porter & Savignano, 1990). Likewise, RIFA decreases songbird nest survival (Campomizzi, 2008), depredates precocial young (Haines et al, 2017) and young reptiles (Allen et al, 1994), and impacts small mammal behavior (Darracq et al, 2016;Holtcamp et al, 2010;Pedersen et al, 2003). However, other studies have shown that RIFA density neither competitively limits native ants nor changes their species richness (King & Tschinkel, 2006;Stuble et al, 2009).…”