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Behavioural and cognitive processes play important roles in mediating an individual's interactions with its environment. Yet, while there is a vast literature on repeatable individual differences in behaviour, relatively little is known about the repeatability of cognitive performance. To further our understanding of the evolution of cognition, we gathered 44 studies on individual performance of 25 species across six animal classes and used metaanalysis to assess whether cognitive performance is repeatable. We compared repeatability (R) in performance (1) on the same task presented at different times (temporal repeatability), and (2) on different tasks that measured the same putative cognitive ability (contextual repeatability). We also addressed whether R estimates were influenced by seven extrinsic factors (moderators): type of cognitive performance measurement, type of cognitive task, delay between tests, origin of the subjects, experimental context, taxonomic class and publication status. We found support for both temporal and contextual repeatability of cognitive performance, with mean R estimates ranging between 0.15 and 0.28. Repeatability estimates were mostly influenced by the type of cognitive performance measures and publication status. Our findings highlight the widespread occurrence of consistent inter-individual variation in cognition across a range of taxa which, like behaviour, may be associated with fitness outcomes. [ABSTRACT FROM AUTHOR]

Host range is a key element of a parasite's ecology and evolution and can vary greatly depending on spatial scale. Generalist parasites frequently show local population structure in relation to alternative sympatric hosts (i.e. host races) and may thus be specialists at local scales. Here, we investigated local population specialization of a common avian nest-based parasite, the hen flea Ceratophyllus gallinae (Schrank), exploiting two abundant host species that share the same breeding sites, the great tit Parus major (Linnaeus) and the collared flycatcher Ficedula albicollis (Temminck). We performed a cross-infestation experiment of fleas between the two host species in two distinct study areas during a single breeding season and recorded the reproductive success of both hosts and parasites. In the following year, hosts were monitored again to assess the long-term impact of cross-infestation. Our results partly support the local specialization hypothesis: in great tit nests, tit fleas caused higher damage to their hosts than flycatcher fleas, and in collared flycatcher nests, flycatcher fleas had a faster larval development rates than tit fleas. However, these results were significant in only one of the two studied areas, suggesting that the location and history of the host population can modulate the specialization process. Caution is therefore called for when interpreting single location studies. More generally, our results emphasize the need to explicitly account for host diversity in order to understand the population ecology and evolutionary trajectory of generalist parasites. [ABSTRACT FROM AUTHOR]

Geographic variation in phenotypes plays a key role in fundamental evolutionary processes such as local adaptation, population differentiation and speciation, but the selective forces behind it are rarely known. We found support for the hypothesis that geographic variation in plumage traits of the pied flycatcher Ficedula hypoleuca is explained by character displacement with the collared flycatcher Ficedula albicollis in the contact zone. The plumage traits of the pied flycatcher differed strongly from the more conspicuous collared flycatcher in a sympatric area but increased in conspicuousness with increasing distance to there. Phenotypic differentiation ( PST) was higher than that in neutral genetic markers ( FST), and the effect of geographic distance remained when statistically controlling for neutral genetic differentiation. This suggests that a cline created by character displacement and gene flow explains phenotypic variation across the distribution of this species. The different plumage traits of the pied flycatcher are strongly to moderately correlated, indicating that they evolve non-independently from each other. The flycatchers provide an example of plumage patterns diverging in two species that differ in several aspects of appearance. The divergence in sympatry and convergence in allopatry in these birds provide a possibility to study the evolutionary mechanisms behind the highly divergent avian plumage patterns. [ABSTRACT FROM AUTHOR]

An increasing need exists to quantify the impact of diagenesis on complex and heterogeneous geological reservoirs and to predict the related field-scale porosity-permeability distribution. Development of approaches to quantify diagenetic events is an important step towards the construction of integrated numerical reservoir models predicting the impact of successive diagenetic events on petrophysical properties at various scales. This article describes two distinct approaches, which allow capturing, quantifying and explaining reservoir heterogeneities of the Jurassic Arab Formation (offshore oilfield in Abu Dhabi, U.A.E.) at the field and plug scale. Based on a classical diagenesis study, whereby the major diagenetic phases were characterized, distribution patterns were highlighted to further explain reservoir heterogeneities through a set of 2D interpolation diagenesis maps across the field. The best reservoir properties are encountered in the central-northern (grainstones with syntaxial calcite overgrowth cement - typical of Arab D) and south-western (dolostones - typical of Arab C) parts of the oilfield. Following another independent approach at the scale of the plug, quantification of rock components and description of the pore space connectivity and geometry are obtained by 2D and 3D image analyses, μ- CT and pore network modelling. This latter approach resulted in a better understanding of the effect of anhydrite dissolution on the pore structure of the investigated dolostone. The overall, presented workflow provides valuable constraints for assessing reservoir heterogeneities in statistical field-scale models. [ABSTRACT FROM AUTHOR]

Parasite success depends on both host profitability and the microenvironment provided by the host, which together define host-parasite compatibility and can differ between hosts. We experimentally disentangled the effects of host profitability and microenvironmental conditions provided by nest material on the reproduction of a nest-based ectoparasite when exploiting its main and an alternative avian host species. Parasite reproductive performance was similar on both hosts when breeding in nests of their own species, suggesting no difference in host-parasite compatibility between hosts. The apparent parasite specialization could therefore result from differences in host-parasite encounter processes. However, when hosts were successful, the main host produced more young in infested nests, whereas the alternative host produced less; furthermore, host reproductive performance was higher in nests of the main host species, suggesting that this nest material alleviates parasitism cost. Therefore, our results suggest different evolutionary responses to parasites of the main and alternative hosts, with either higher tolerance or higher resistance, modulated by nest material. [ABSTRACT FROM AUTHOR]