Search Results (4)

There have been few advances in understanding the organization and dynamics of ants in tropical dry forests. The latter are a seriously threatened ecosystem, and ants are important indicators of diversity, disturbance, and restoration in forest ecosystems. Using diversity data and morphofunctional traits, we evaluated the spatial and temporal variation of taxonomic and functional ant groups; in addition, we explored the variation in functional traits and diversity among communities. Ants were sampled during the dry and rainy seasons using mini-Winkler bags. A total of 9 subfamilies, 57 genera, and 146 species were collected. Ant species composition and richness varied both spatially (75 to 119 species) and temporally (121 and 127 species). The fragments from N2 and N3 showed higher diversity than those from N1. The dissimilarity among all areas was moderate (50–60%), mainly attributable to species turnover processes (77%). Twenty functional groups were identified. The N3 fragments had the highest functional diversity, with lower resistance to species loss, while the N1 and N2 fragments reduced functional diversity and increased similarity among species. Our results highlight the importance of integrating a functional analysis with the taxonomic assessment of ants as an important contribution to understanding the organization and dynamics of this community of insects that inhabit the tropical dry forest. Full article

The genus Strumigenys is the third most diverse among ants, having been reviewed globally. Despite this comprehensive review, new species are frequently discovered in most biogeographic regions. Here, we describe two new species, Strumigenys itannae sp. nov. and Strumigenys xoko sp. nov., based on material collected in the Amazon and the Brazilian Atlantic Forest. Additionally, new records for S. castanea, S. metrix, and S. orchibia are provided, expanding the known distribution of these species. We discuss morphological variation in S. schulzi and provide biological notes that indicate some species within the schulzi group are arboreal inhabitants. We provided an identification key for the newly described species as an amendment to the identification key for the Neotropical Strumigenys. Full article

The grain for which an observer conducts a study is an important determinant of its outcome. Studies of ants have considered spatial grains spanning from single meters to entire forest ecosystems and found patterns related to nutrient availability, leaf litter depth, disturbance, and forest composition. Here, we examine a Bornean leaf litter ant community at small (1–4 m) and large (50–250 m) spatial scales and consider the differences in community structure using structured 1 m² quadrats sampled via leaf litter sifting and Berlese extraction. We found that small-scale patterns in ant abundance and richness did not spatially autocorrelate within a plot until >1.5 m. Leaf litter characteristics, forest stand characteristics and sampling season were homogenous among our sites, suggesting that macro-scale stand variables are not largely regulating the small spatial scale ant communities: These may be driven by microclimate, competition, niche space, nutrient available, microclimatic conditions, or other localized effects. Further experimental work is needed to elicit causal mechanisms. Full article

Identification of priority areas for conservation is crucial for the maintenance and protection of biodiversity, particularly in tropical forests where biodiversity continues to be lost at alarming rates. Surveys and research on umbrella species can provide efficient and effective approaches to identify potential areas for conservation at small geographical scales. Army ants of the genus Eciton are keystone species in neotropical forests due to their major role as top predators and due to the numerous vertebrate- and invertebrate associated species that depend upon their colonies for survival. These associates range from the iconic army ant-following birds to a wide range of arthropod groups, some of which have evolved intricate morphological, behavioural and/or chemical strategies to conceal their presence and integrate into the colony life. Furthermore, Eciton colonies require large forested areas that support a diverse leaf litter prey community and several field-based and genetic studies have demonstrated the negative consequences of forest fragmentation for the long-term maintenance of these colonies. Therefore, Eciton species will not only act as umbrella for their associates but also for many other species in neotropical forests, in particular for those that require a large extent of forest. This review summarises past and recent accounts of the main taxonomic groups found associated with Eciton colonies, as well research assessing the impact of forest fragmentation on this army ant, to encourage the adoption of Eciton army ants as umbrella species for the identification of priority areas for conservation and assessments of the effect of disturbance in neotropical forests. Full article