Understanding habitat requirements of species is important in
conservation. As an obligate ant nest associate, the survival of the
globally vulnerable shining guest ant, Formicoxenus nitidulus, is strictly tied to that of its hosts (mound building Formica ants). We investigated how host species, nest density, inter-nest distance and nest mound size relate to the occurrence of F. nitidulus. In total, 166 red wood ant nests were surveyed in SW Finland (120 Formica polyctena, 25 F. rufa, 14 F. aquilonia, 5 F. pratensis, and 2 F. lugubris). Overall, F. nitidulus was found in 60% of the nests. For the actual analysis, only F. polyctena and F. rufa nests were included due to the small number of other nests. F. nitidulus was more likely to be found among F. polyctena than F. rufa.
Also, while inter-nest distance was not important, a high nest density,
commonly found in polydomous (multi-nest) wood ant colonies, was
beneficial for F. nitidulus. The
guest ant was also more likely to be found in large host nests than
small nests. Thus, our results show that the best habitat for the guest
ant is a dense population of host nest mounds with a high proportion of
large mounds. Conservation efforts should be directed at keeping the
quality of the red wood ant habitats high to preserve their current
populations and to increase colonization. This will not only benefit the
guest ant, but also a plethora of other species, and help in
maintaining the biodiversity of forests.