Studies of ant communities, like research examining ant diversity (e.g., Ant Diversity Studies 2018), have been of perennial interest.
- Grevé, M. E., M. Houadria, A. N. Andersen, and F. Menzel. 2019. Niche differentiation in rainforest ant communities across three continents. Ecology and Evolution. 9:8601-8615. doi:10.1002/ece3.5394
Abstract A central prediction of niche theory is that biotic communities are structured by niche differentiation arising from competition. To date, there have been numerous studies of niche differentiation in local ant communities, but little attention has been given to the macroecology of niche differentiation, including the extent to which particular biomes show distinctive patterns of niche structure across their global ranges. We investigated patterns of niche differentiation and competition in ant communities in tropical rainforests, using different baits reflecting the natural food spectrum. We examined the extent of temporal and dietary niche differentiation and spatial segregation of ant communities at five rainforest sites in the neotropics, paleotropics, and tropical Australia. Despite high niche overlap, we found significant dietary and temporal niche differentiation in every site. However, there was no spatial segregation among foraging ants at the community level, despite strong competition for preferred food resources. Although sucrose, melezitose, and dead insects attracted most ants, some species preferentially foraged on seeds, living insects, or bird feces. Moreover, most sites harbored more diurnal than nocturnal species. Overall niche differentiation was strongest in the least diverse site, possibly due to its lower number of rare species. Both temporal and dietary differentiation thus had strong effects on the ant assemblages, but their relative importance varied markedly among sites. Our analyses show that patterns of niche differentiation in ant communities are highly idiosyncratic even within a biome, such that a mechanistic understanding of the drivers of niche structure in ant communities remains elusive.
- Dejean, A., J. Orivel, M. Leponce, A. Compin, J. H. C. Delabie, F. Azemar, and B. Corbara. 2018. Ant-plant relationships in the canopy of an Amazonian rainforest: the presence of an ant mosaic. Biological Journal of the Linnean Society. 125:344-354. doi:10.1093/biolinnean/bly125
Abstract Using different techniques to access the canopy of an Amazonian rainforest, we inspected 157 tree crowns for arboreal ants. Diversity statistics showed that our study sample was not representative of the tree and ant populations due to their high diversity in Amazonian rainforests, but permitted us to note that a representative part of territorially dominant arboreal ant species (TDAAs) was inventoried. Mapping of TDAA territories and use of a null model showed the presence of an ant mosaic in the upper canopy, but this was not the case in the sub-canopy. Among the TDAAs, carton-nesting Azteca dominated (52.98% of the trees) whereas ant-garden ants (Camponotus femoratus and Crematogaster levior), common in pioneer formations, were secondarily abundant (21.64% of the trees), and the remaining 25.37% of trees sheltered one of 11 other TDAAs. The distribution of the trees forming the upper canopy influences the structure of the ant mosaic, which is related to the attractiveness of some tree taxa for certain arboreal ant species and represents a case of diffuse coevolution.
- Gray, R. E. J., R. M. Ewers, M. J. W. Boyle, A. Y. C. Chung, and R. J. Gill. 2018. Effect of tropical forest disturbance on the competitive interactions within a diverse ant community. Scientific Reports. 8:12. doi:10.1038/s41598-018-23272-y
Abstract Understanding how anthropogenic disturbance influences patterns of community composition and the reinforcing interactive processes that structure communities is important to mitigate threats to biodiversity. Competition is considered a primary reinforcing process, yet little is known concerning disturbance effects on competitive interaction networks. We examined how differences in ant community composition between undisturbed and disturbed Bornean rainforest, is potentially reflected by changes in competitive interactions over a food resource. Comparing 10 primary forest sites to 10 in selectively-logged forest, we found higher genus richness and diversity in the primary forest, with 18.5% and 13.0% of genera endemic to primary and logged respectively. From 180 hours of filming bait cards, we assessed ant-ant interactions, finding that despite considered aggression over food sources, the majority of ant interactions were neutral. Proportion of competitive interactions at bait cards did not differ between forest type, however, the rate and per capita number of competitive interactions was significantly lower in logged forest. Furthermore, the majority of genera showed large changes in aggression-score with often inverse relationships to their occupancy rank. This provides evidence of a shuffled competitive network, and these unexpected changes in aggressive relationships could be considered a type of competitive network re-wiring after disturbance.
- Philpott, S. M., Z. Serber, and A. De la Mora. 2018. Influences of Species Interactions With Aggressive Ants and Habitat Filtering on Nest Colonization and Community Composition of Arboreal Twig-Nesting Ants. Environmental Entomology. 47:309-317. doi:10.1093/ee/nvy015
Abstract Ant community assembly is driven by many factors including species interactions (e.g., competition, predation, parasitism), habitat filtering (e.g., vegetation differences, microclimate, food and nesting resources), and dispersal. Canopy ant communities, including dominant and twig-nesting ants, are structured by all these different factors, but we know less about the impacts of species interactions and habitat filters acting at the colonization or recruitment stage. We examined occupation of artificial twig nests placed in shade trees in coffee agroecosystems. We asked whether species interactions—aggression from the dominant canopy ant, Azteca sericeasur Longino (Hymenoptera: Formicidae)—or habitat filtering—species of tree where nests were placed or surrounding vegetation—influence colonization, species richness, and community composition of twig-nesting ants. We found 20 species of ants occupying artificial nests. Nest occupation was lower on trees with A. sericeasur, but did not differ depending on tree species or surrounding vegetation. Yet, there were species-specific differences in occupation depending on A. sericeasur presence and tree species. Ant species richness did not vary with A. sericeasur presence or tree species. Community composition varied with A. sericeasur presence and surrounding vegetation. Our results suggest that species interactions with dominant ants are important determinants of colonization and community composition of twig-nesting ants. Habitat filtering at the level of tree species did not have strong effects on twig-nesting ants, but changes in coffee management may contribute to differences in community composition with important implications for ant conservation in agricultural landscapes, as well as biological control of coffee pests.
- Roeder, K. A., D. V. Roeder, and M. Kaspari. 2018. The role of temperature in competition and persistence of an invaded ant assemblage. Ecological Entomology. 43:774-781. doi:10.1111/een.12663
Abstract 1. To achieve numerical dominance, an ectotherm consumer requires a sizeable abiotic window in which it can forage. Here we explore how one abiotic factor, temperature, provides opportunity and regulates the impact of the invasive red imported fire ant, Solenopsis invicta, on an urban ant assemblage. 2.We first quantified S. invicta’s ability to outcompete native species by contrasting its foraging biomass to that of its potential competitors. In doing so, we found that S. invicta deployed more ant biomass at baits than the estimated whole colony biomass of three of the four co-occurring native species. It did so across c. 75% of the hours in a summer day, those hours below its thermal maximum of 49 ∘C. Higher thermal maxima allowed two native species to avoid encountering workers of S. invicta. 3. Exclosure experiments revealed that a third species, Dorymyrmex flavus, more similar in body size and thermal tolerance to S. invicta, was competitively suppressed by the invasive. Carbon and nitrogen stable isotope analysis suggests that D. flavus’ persistence is likely due to dietary differences. 4. Although thermal and dietary traits help predict how species coexist in this invaded assemblage, one key to S. invicta’s success is likely to be its ability to forage in all but 6 h of a summer’s day.
- Sorvari, J. 2018. Wood ant assemblages of Formica rufa group on lake islands and in mainland woodland in Central Finland. Entomologica Fennica. 29:21-29.
Abstract Associations of island size and isolation on the occurrence and species richness of five wood ant species of the Formica rufa group (Formica rufa, Formica aquilonia, Formica lugubris, Formica polyctena and Formica pratensis) was tested in the Lake Konnevesi archipelago in Central Finland. In addition, the species composition was compared to that of mainland forests of the same region. Island isolation had no associations with the wood ant occurrence in this archipelago, but for most species, increasing island size was positively associated with the occurrence probability. According to the findings among the five species, Formica lugubris is the best adapted for insular living. There was a positive species area relationship as the species richness of wood ants increased with an increasing island size. The island community of wood ants was dominated by colonies of the monogynous (single queen) species whereas the mainland community was dominated by those of polygynous (multiple queen) species.
- Lange, D., A. A. Vilela, G. Erdogmus, A. B. Barbosa, S. C. Costa, and V. Stefani. 2015. Temporal dynamic of foraging of epigeic ants in an urban forest fragment. Bioscience Journal. 31:1501-1511.
Abstract The present study aimed to investigate the foraging dynamic of an ant community in an urban semideciduous mesophitic forest. A total of 4,297 individuals, distributed in 23 species, seven genera and four subfamilies were sampled in January, April, July and October of 2010. Four ant species guilds were found: leaf cutters, soil-dominant omnivores, soil and vegetation opportunists and large-sized epigaeic predators. There were no significant differences in total of species richness and abundance of individuals in samples among the months evaluated. However, there was a clear substitution (turnover) of species over the months. Nine species were sampled exclusively in the rainy period and five species were present only during the dry period. Thus, the species turnover over the months support the hypothesis that ant communities present a temporal dynamics in their foraging activities even in an urban forest fragment. In general, the abundance of ants foraging on soil was greatest during the months with greater rainfall. However, two species belonging to the guild of opportunistic ants from soil and vegetation doubled the number of foraging individuals in period during the months with less precipitation. These findings support that ant communities, independent of isolation and environment (urban or natural), have temporal dynamics that arise from factors relating to the biology and behavior of the group.
- Ossola, A., M. A. Nash, F. J. Christie, A. K. Hahs, and S. J. Livesley. 2015. Urban habitat complexity affects species richness but not environmental filtering of morphologically-diverse ants. PeerJ. 3. doi:10.7717/peerj.1356
Abstract Habitat complexity is a major determinant of structure and diversity of ant assemblages. Following the size-grain hypothesis, smaller ant species are likely to be advantaged in more complex habitats compared to larger species. Habitat complexity can act as an environmental filter based on species size and morphological traits, therefore affecting the overall structure and diversity of ant assemblages. In natural and semi-natural ecosystems, habitat complexity is principally regulated by ecological successions or disturbance such as fire and grazing. Urban ecosystems provide an opportunity to test relationships between habitat, ant assemblage structure and ant traits using novel combinations of habitat complexity generated and sustained by human management. We sampled ant assemblages in low-complexity and high-complexity parks, and high-complexity woodland remnants, hypothesizing that (i) ant abundance and species richness would be higher in high-complexity urban habitats, (ii) ant assemblages would differ between low- and high-complexity habitats and (iii) ants living in high-complexity habitats would be smaller than those living in low-complexity habitats. Contrary to our hypothesis, ant species richness was higher in low-complexity habitats compared to high-complexity habitats. Overall, ant assemblages were significantly different among the habitat complexity types investigated, although ant size and morphology remained the same. Habitat complexity appears to affect the structure of ant assemblages in urban ecosystems as previously observed in natural and semi-natural ecosystems. However, the habitat complexity filter does not seem to be linked to ant morphological traits related to body size.