Natural history of ants: What we (do not) know about trophic and temporal niches of neotropical species

Abstract

Our understanding of the natural history of Neotropical ants is limited, due to lack of descriptive efforts and widespread use of morphospecies in literature. Use of trophic resources and period of activity are two central niche aspects little explored for most species. This work aimed to broadly review the literature and provide empirical field data on these aspects for 23 species. The fieldwork was carried out in the Atlantic forest of southern Brazil. Trophic and temporal niches were assessed with pitfall traps and seven kinds of bait representing natural resources. Crushed insects were the preferred resource, whereas bird feces and living prey were less exploited. Most species broadly used the resources, but pronounced quantitative differences were found. Odontomachus chelifer (Latreille, 1802) and Pachycondyla striata Smith, 1858 were relatively well studied and field data matched previous accounts. They were the only species that consistently used large prey, and avoided oligosaccharides. Wasmannia auropunctata (Roger, 1863) differed remarkably from previous studies, using feces as its sole trophic resource. The six Pheidole species had no previous records and presented quantitative differences in resource use. Most species had no strong preference for period of activity. Camponotus zenon Forel, 1912 was nocturnal and Crematogaster nigropilosa Mayr, 1870, Linepithema iniquum (Mayr, 1870) and Linepithema pulex Wild, 2007 were diurnal. Complementary methods, context-dependence and descriptive studies have a central role in the understanding of ant natural history. Community assessments can contribute significantly to this knowledge if researchers also pay attention to the individual species involved.