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Article Reference Prestonellinae – validation of the name as a new subfamily of Bothriembryontidae (Mollusca, Gastropoda, Orthalicoidea)
Located in Library / RBINS Staff Publications 2016
Article Reference Hydroclimatic conditions and fishing practices at Late Paleolithic Makhadma 4 (Egypt) inferred from stable isotope analysis of otoliths
The late Paleolithic site of Makhadma 4, located along the Nile River in Upper Egypt, yielded an important ichthyofauna characterized by a very high proportion of tilapia (Oreochromis niloticus). We used isotopic analysis (d18O) of well-preserved otoliths (“ear stones”) of tilapia to reconstruct the former hydrological conditions, as well as the fishing strategies of the site's inhabitants. Otoliths from two modern fish captured in the Nile River near Esna were also examined to test how accurately tilapia otoliths reflect their ambient environment. All otoliths were sequentially micromilled to recover high resolution isotopic profiles along the main growth axis. Comparison of the modern otolith profiles with environmental data shows that tilapia d18O values record seasonal variations of the modern Nile hydroclimate but that their values are offset. The archaeological otoliths record very large intraindividual cyclical variations in d18O values, with relatively consistent amplitude, as well as very high seasonal maximum values (up to þ8.3‰), compared with the modern otoliths. The hydrological regime of the water body in which the archaeological fish lived was characterized by a reduced Nile water inflow that could not negate the effect of local evaporation during spring. The reconstructed hydrological conditions are in accordance with a new model of Nilotic behavior that assumes the creation of lakes by damming of the Nile as a result of a high eolian activity during hyper-arid periods of the Late Pleistocene. Although large seasonal evaporation may have resulted in a severe seasonal reduction in the lake's volume and extent, the lake was, nevertheless, maintained for several years. Cyclic variations in otolith d18O values permit reconstruction of the period of the hydrological cycle during which the fish were captured. Fishing of young individuals occurred mostly after the maximum input of inflow water from the Nile, when evaporitic conditions were at their lowest, i.e. during fall.
Located in Library / RBINS Staff Publications 2017
Inproceedings Reference Animal exploitation during the Iron Age at Tepe Düzen (SW Turkey): preliminary results
Located in Library / RBINS Staff Publications 2017
Inproceedings Reference Faunal analysis of the Castle of Aqaba (Jordan) : preliminary results
Located in Library / RBINS Staff Publications 2017
Article Reference Dominance-diversity relationships in ant communities differ with invasion
The relationship between levels of dominance and species richness is highly contentious, especially in ant communities. The dominance-impoverishment rule states that high levels of dominance only occur in species-poor communities, but there appear to be many cases of high levels of dominance in highly diverse communities. The extent to which dominant species limit local richness through competitive exclusion remains unclear, but such exclusion appears more apparent for non-native rather than native dominant species. Here we perform the first global analysis of the relationship between behavioral dominance and species richness. We used data from 1,293 local assemblages of ground-dwelling ants distributed across five continents to document the generality of the dominance-impoverishment rule, and to identify the biotic and abiotic conditions under which it does and does not apply. We found that the behavioral dominance-diversity relationship varies greatly, and depends on whether dominant species are native or non-native, whether dominance is considered as occurrence or relative abundance, and on variation in mean annual temperature. There were declines in diversity with increasing dominance in invaded communities, but diversity increased with increasing dominance in native communities. These patterns occur along the global temperature gradient. However, positive and negative relationships are strongest in the hottest sites. We also found that climate regulates the degree of behavioral dominance, but differently from how it shapes species richness. Our findings imply that, despite strong competitive interactions among ants, competitive exclusion is not a major driver of local richness in native ant communities. Although the dominance-impoverishment rule applies to invaded communities, we propose an alternative dominance-diversification rule for native communities.
Located in Library / RBINS Staff Publications 2018
Article Reference Ants impact the composition of the aquatic macroinvertebrate communities of a myrmecophytic tank bromeliad
Located in Library / RBINS Staff Publications 2018
Article Reference Ant–plant relationships in the canopy of an Amazonian rainforest: the presence of an ant mosaic
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.
Located in Library / RBINS Staff Publications 2018
Article Reference Aquatic life in Neotropical rainforest canopies: Techniques using artificial phytotelmata to study the invertebrate communities inhabiting therein
In Neotropical rainforest canopies, phytotelmata ("plant-held waters") shelter diverse aquatic macroinvertebrate communities, including vectors of animal diseases. Studying these communities is difficult because phytotelmata are widely dispersed, hard to find from the ground and often inaccessible. We propose here a method for placing in tree crowns "artificial phytotelmata" whose size and shape can be tailored to different research targets. The efficacy of this method was shown while comparing the patterns of community diversity of three forest formations. We noted a difference between a riparian forest and a rainforest, whereas trees alongside a dirt road cutting through that rainforest corresponded to a subset of the latter. Because rarefied species richness was significantly lower when the phytotelmata were left for three weeks rather than for six or nine weeks, we recommend leaving the phytotelmata for twelve weeks to permit predators and phoretic species to fully establish themselves.
Located in Library / RBINS Staff Publications 2018
Article Reference How common is trophobiosis with hoppers (Hemiptera: Auchenorrhyncha) inside ant nests (Hymenoptera: Formicidae)? Novel interactions from New Guinea and a worldwide overview
Trophobiotic interactions between ants and honeydew-providing hemipterans are widespread and are one of the key mechanisms that maintain ant super-abundance in ecosystems. Many of them occur inside ant nests. However, these cryptic associations are poorly understood, particularly those with hoppers (suborder Auchenorrhyncha). Here, we study tree-dwelling ant and Hemi­ptera communities in nests along the Mt. Wilhelm elevational gradient in Papua New Guinea and report a new case of this symbiosis between Pseudolasius Emery, 1887 ants and planthoppers. Furthermore, we provide a worldwide review of other ant-hopper interactions inside ant-built structures and compare their nature (obligate versus facultative) and distribution within the suborder Auchenorrhyncha. The novel interactions were observed in nests located at the tree trunk bases or along the whole trunks. Only immature planthopper stages were found inside nests, so full species identifications were not possible. However, nymph morphology and molecular data (18S and COI genes) indicated four related species of the family Flatidae (infraorder Fulgoromorpha) associated with Pseudolasius. Ant-planthopper occurrences were relatively rare (6% of all trophobiotic interactions) and peaked at mid-elevation (900 m above sea level). Pseudolasius was the only genus associated with planthoppers in the communities, with most cases monopolised by a single species, P. breviceps Emery, 1887. In contrast, all other ant genera tended various scale insects (Sternorrhyncha: Coccoidea). This apparent partner-specificity is rare: Worldwide, there are only about ten reported cases of obligate symbiosis in ant nests, distributed in five of the thirty-three Auchenorrhyncha families. Those trophobioses are randomly dispersed across the Auchenorrhyncha phylogeny, and thus likely originated multiple times independently. Further research on both adult and nymph hopper life history is needed to answer how these symbioses, notably rare in hoppers compared with other hemi­pterans, are maintained.
Located in Library / RBINS Staff Publications 2018
Article Reference Resource use and food preferences in understory ant communities along a complete elevational gradient in Papua New Guinea
Elevational gradients provide an interesting opportunity for studying the effect of climatic drivers over short distances on the various facets of biodiversity. It is globally assumed that the decrease in species richness with increasing elevation follows mainly the decrease in ecosystem productivity, but studies on functional diversity still remain limited. Here, we investigated how resource use and food preferences by both individual ant species and communities foraging in the understory vary with elevation along a complete elevational gradient (200 to 3200 m asl). Five bait types reflecting some of the main ecosystem processes in which ants are involved were tested: mutualism (sucrose and melezitose), predation (live termites), and detritivory (crushed insects and chicken feces). The observed monotonic decrease in both species richness and occurrences with elevation increase was accompanied by changes in some of the tested ecosystem processes. Such variations can be explained by resource availability and/or resource limitation: Predation and bird feces removal decreased with increasing elevation possibly reflecting a decline in species able to use these resources, while insect detritivory and nectarivory were most probably driven by resource limitation (or absence of limitation), as their relative use did not change along the gradient. Consequently, resource attractiveness (i.e., food preferences at the species level) appears as an important factor in driving community structuring in ants together with the abiotic environmental conditions.
Located in Library / RBINS Staff Publications 2018