A multidimensional functional trait analysis of resource exploitation in European ants

Abstract

The major factors explaining ecological variation in plants have been widely discussed over the last decade thanks to numerous studies that have examined the covariation that exists between pairs of traits. However, multivariate relationships among traits remain poorly characterized in animals. In this study, we aimed to identify the main multivariate trait dimensions that explain variance in important functional traits related to resource exploitation in ants. To this end, we created a large ant trait database. This database includes information on 11 traits that are important in ant resource exploitation; data were obtained for 150 European species found in different biomes. First, we examined the pairwise correlations between the traits included in the database. Second, we used multivariate analyses to identify potential trait dimensions. Our study shows that, to a great extent, resource exploitation strategies align along two main trait dimensions. The first dimension emerged in both the overall and group-specific analyses, where it accounted for the same pairwise trait correlations. The second dimension was more variable, as species were grouped by levels of taxonomy, habitat, and climate. These two dimensions included most of the significant pairwise trait correlations, thus highlighting that complementarity, but also redundancy, exists among different pairs of traits. The first dimension was associated with behavioral dominance: dominance was associated with large colony size, presence of multiple nests per colony, worker polymorphism, and a collective foraging 'strategy. The second dimension was associated with resource partitioning along dietary and microhabitat lines: it ranged from species that consume liquid foods, engage in group foraging, and mainly nest in the vegetation to species that consume insects and seeds, engage in individual foraging, and demonstrate strictly diurnal activity. Our findings establish a proficient ecological trait-based animal research that minimizes the number of traits to be measured while maximizing the number of relevant trait dimensions. Overall, resource exploitation in animals might be framed by behavioral dominance, foraging strategy, diet, and nesting habitat; the position of animal species within this trait space could provide relevant information about their distribution and abundance, for today as well as under future global change scenarios.

Trait‐based ecology of terrestrial arthropods

“…First, the extent of phylogenetic relatedness among species in a community varies considerably; while some studies use closely related communities (e.g. ants; Retana, Arnan & Cerdá, ), others use distantly related communities (e.g. isopods and millipedes; Coulis et al ., ).…”

Social Life in Arid Environments: The Case Study of Cataglyphis Ants

“…Second, Cataglyphis workers are largely scavengers of sparsely dispersed food items (53), necessitating communication with nestmates only when the food item is too large to be carried alone. Third, in relatively small colony sizes, as occur in most Cataglyphis species, lone foraging is efficient enough for colony needs (12,116). The second and third factors may explain why species that live in less arid environments (e.g., the cursor group) have not reverted to mass recruitment despite the alleviation of some ecological constraints.…”

Morphological structure of ant assemblages in tropical and temperate forests

“…Among the arthropods, ants are an ideal taxonomic group for investigating relationships between morphology, traits, and assemblage structure because they (i) are abundant, comprising the dominant fraction of animal biomass in most terrestrial ecosystems (Wilson and Hölldobler, 2005), (ii) perform a range of important ecosystems functions (Del Toro et al 2012), (iii) exhibit a very large morphological diversity at very small scales (Silva and Brandão 2010), and (iv) vary in composition along environmental gradients (Gotelli and Ellison 2002). In addition, many studies have shown that ant species have specific traits that are correlated with environmental conditions (Wiescher et al 2012), macro-or microhabitat structure (Kaspari and Weiser 1999, Gibb and Parr 2010, Yates et al 2014) and resource exploitation (Retana et al 2015). Finally, recent research with stable isotopes has identified 5 morphological space occupied by temperate and tropical ant assemblages.…”