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What forces structure ecological assemblages? A key limitation to general insights about assemblage structure is the availability of data that are collected at a small spatial grain (local assemblages) and a large spatial extent (global coverage). Here, we present published and unpublished data from 51 ,388 ant abundance and occurrence records of more than 2,693 species and 7,953 morphospecies from local assemblages collected at 4,212 locations around the world. Ants were selected because they are diverse and abundant globally, comprise a large fraction of animal biomass in most terrestrial communities, and are key contributors to a range of ecosystem functions. Data were collected between 1949 and 2014, and include, for each geo-referenced sampling site, both the identity of the ants collected and details of sampling design, habitat type, and degree of disturbance. The aim of compiling this data set was to provide comprehensive species abundance data in order to test relationships between assemblage structure and environmental and biogeographic factors. Data were collected using a variety of standardized methods, such as pitfall and Winkler traps, and will be valuable for studies investigating large-scale forces structuring local assemblages. Understanding such relationships is particularly critical under current rates of global change. We encourage authors holding additional data on systematically collected ant assemblages, especially those in dry and cold, and remote areas, to contact us and contribute their data to this growing data set.

International audience; How polygyny evolved in social insect societies is a long-standing question. This phenomenon, which is functionally similar to communal breeding in vertebrates, occurs when several queens come together in the same nest to lay eggs that are raised by workers. As a consequence, polygyny drastically reduces genetic relatedness among nestmates. It has been suggested that the short-term benefits procured by group living may outweigh the costs of sharing the same nesting site and thus contribute to organisms rearing unrelated individuals. However, tests of this hypothesis are still limited. To examine the evolutionary emergence of polygyny, we reviewed the literature to build a data set containing life-history traits for 149 Palearctic ant species and combined this data set with a reconstructed phylogeny. We show that monogyny is the ancestral state and that polygyny has evolved secondarily and independently throughout the phylogenetic tree. The occurrence of polygyny is significantly correlated with larger colony size, dependent colony founding and ecological dominance. Although polydomy (when a colony simultaneously uses several connected nests) tends to occur more frequently in polygynous species, this trend is not significant when phylo-genetic history is accounted for. Overall, our results indicate that polygyny may have evolved in ants in spite of the reduction in nestmate relatedness because large colony size provides immediate ecological advantages, such as the more efficient use of temporal food resources. We suggest that the competitive context of ant communities may have provided the conditions necessary for the evolution of polygyny in some clades.

In this paper we analyze emigration from nests by the polydomous ant Cataglyphis iberica. Social carrying of workers of this species between different nests of the colony is frequent. In Bellaterra (Barcelona, NE Spain), we monitored field emigration of C. iberica by noting for each nest the migratory behavior of C. iberica workers and, when the nests were attacked by another ant species, Camponotus foreli, we noted the number of C. foreli workers involved in the attacks. Emigration of C. iberica from nests was highly variable. We suggest the main factor determining emigration by this species was attack by workers of C. foreli, so emigration from C. iberica nests was much faster when harassment by C. foreli increased. The system of multiple nests of C. iberica enables this species to abandon attacked nests and to reinstall their population in other nests of the same colony. This reduces risk to the colonies because the route between the different nests is well known by transporter workers. © 2007 Japan Ethological Society and Springer.