Living within fallen palm leaves: the discovery of an unknown Blommersia (Mantellidae: Anura) reveals a new reproductive strategy in the amphibians of Madagascar

We describe a new mantelline frog of the genus Blommersia found in rainforest in North East Madagascar, from the protected areas of Ambatovaky, Betampona, Masoala, and Zahamena. Blommersia angolafa n.sp. is a small frog, with a body size of 17–21 mm, expanded finger and toe tips, and colouration ranging from yellow to dark brown, with pale-bluish spots on the flanks and light tips of fingers and toes. A peculiar aspect characterising this new species is its novel life history and reproductive mode. Both sexes live and breed in a phytotelmic habitat of water accumulated within fallen prophylls and fallen leaf sheaths of at least three species of Dypsis palms. Within these phytotelmata, egg laying and complete larval development occur. Thus, B. angolafa n.sp. represents a new evolutionary lineage of Malagasy frogs in which phytotelmy is known. Up to now, reproduction in phytotelmata in Malagasy frogs has been reported for many cophyline microhylids, most species of Guibemantis, Mantella laevigata, and possibly in a still-undescribed species belonging to the genus Spinomantis. We consider the reproductive mode of B. angolafa as a derived character, having evolved from the more typical reproduction in lentic water bodies. The general scarcity of lentic habitats in Malagasy rainforests may have provided the conditions that favoured the evolution of this phytotelmic breeding strategy. The new species, being specialised to a habitat represented by a few selected Dypsis species, potentially suffers the selective exploitation of these palms.     

Transesterification of Caesalpinia eriostachys seed oil using heterogeneous and homogeneous basic catalysts

Caesalpinea eriostachys seed oil, as a source of triglycerides with potential application for biodiesel production in Mexico is introduced. Its lipid profile obtained by Gas Chromatography-Mass Spectrometry (GC-MS) revealed saturated and unsaturated glycerol esters as the constituents. Therefore, heterogeneous and homogeneous catalyzed transesterification reactions were assayed employing ZnAl hydrotalcites and KOH, as the catalysts, respectively. The transesterification reactions yielded 59% for Zn/Al(2), 79% for Zn/Al(4), and 90% for KOH, depicting typical behavior, as in biodiesel production data from literature, where Zn-Al hydrotalcites or KOH were assayed. The caloric, density, viscosity values, and fatty acid methyl esters profile from reaction products were concordant to EN 14214, suggesting C. eriostachys as a promising feedstock for biodiesel production.     

Measurements of selected PCBs in open urban ambient air of Madrid (Spain)

The focus of this study was to characterize the concentration levels of selected PCBs and compare them to compiled data in order to contribute to the international database. The sampling site is located in the outskirts of Madrid and can be considered an open urban area. 32 samples of air were taken from February 1998 to June 1998 by using a high volume air sampler. Glass fiber filters and polyurethane foam (PUF) were used to collect the paniculate and gas phase material, respectively. PUF plugs were Soxhlet extracted and filters were ultrasonically extracted by using pesticide-grade hexane and dichloromethane, respectively. The cleanup procedure was carried out on a florisil column with hexane and hexane/dichloromethane as elution solvents. GC/MS in a selected ion monitoring mode was used for quantification and 29 selected PCBs congeners were analyzed.     

Variable within-brood maternal provisioning in newly extruded embryos of Homarus gammarus

Offspring quality of decapod crustaceans has been widely studied, with special emphasis on the sources of variability determining embryonic and larval quality. Nevertheless, maternal provisioning has commonly been overlooked as a potential source of offspring within-brood variability. In the present study, the existence of variable maternal provisioning was assessed through the analysis of the fatty acid (FA) profile of newly extruded embryos from different regions of the brooding chamber of Homarus gammarus. Significant differences in the FA profile of embryos sampled from different pleopods and sides of the brooding chamber were recorded. Significant deviations of the overall mean of each surveyed female were also observed for essential FA, particularly 20:4n-6, 20:5n-3 and 22:6n-3. Lipid energy available to fuel embryogenesis also varied among embryos sampled from different regions of the brooding chamber. Results suggest variable female investment at oocyte production, which may be amplified during the incubation period of developing embryos by differential lipid catabolism. For the first time, maternal provisioning is evidenced as an additional source for within-brood variability in the FA profile of embryos.     

Nonparametric circular methods for exploring environmental data

The goal of this work is to introduce nonparametric kernel methods for density and regression estimation for circular data, and illustrate their use by a brief simulation study and real data application. Apart from supplying practitioners with a license free and easy to run code for the use of these methods, our aim is also to provide solutions to practical problems that may be encountered in their application. The real data examples belong to the International Polar Year project, concerned with the environmental change in the polar regions.     

Individual differences in sampling behaviour predict social information use in zebra finches

When animals have to decide where to forage, what to eat or with whom to mate, they can base their decisions on either socially or personally acquired information. In accordance with theoretical predictions, there is experimental evidence that animals adjust the weight they give to both sources of information depending on circumstances. Notably, several studies have demonstrated that individuals rely more on social information when personal information is difficult to acquire or unreliable, because these conditions leave them uncertain as how to behave. Yet, even when individuals are exposed to the same conditions, they generally differ widely in the value they attribute to social and personal information. These differences suggest that the tendency to rely on social information would also depend on intrinsic characteristics that affect, for instance, individual efficiency in collecting personal information. To address this issue, we conducted laboratory experiments using female zebra finches (Taeniopygia guttata) and we tested them under three consecutive conditions. First, we evaluated their reliance on social information in a mating context and in a foraging context. Then, we measured their efficiency in acquiring personal information by recording their sampling behaviour when searching for hidden food. We found that females that sampled their environment less actively consistently relied on social information to a greater extent compared with those that invested more in sampling. Contrary to what is generally assumed, then, our study demonstrates that social information use is not entirely flexible and context dependent.     

Analysis of time-scaling properties in forest-fire sequence observed in Italy

The investigation of the temporal fluctuations in forest fires is an important topic in the context of environmental sciences. Time-scaling scale-invariant methodologies have been used to characterize the temporal properties of forest-fire sequences detected in the Italian territory. Our findings reveal that the fire sequences can be considered as fractal processes with a high degree of time-clusterization of the events. The time-clustering phenomenon is clearly visible from timescales of order of days. Furthermore the fire sequences observed with decreasing latitude tend to be more time-clusterized.