Les Chauves-souris de Guyane

Ce livre s’adresse autant au grand public qu’aux naturalistes. Un texte scientifiquement rigoureux, mais accessible à tous, décrit les principaux traits biologiques des chauves-souris de Guyane, suivi par une clé illustrée permettant de déterminer, à partir de caractères externes, la majeure partie des 100 espèces recensées dans le département. Les photos de 57 espèces sont présentées sur des planches en couleurs, révélant l’étonnante diversité des faciès, conséquences d’adaptations variées. Insectivores aux stratégies multiples, carnivores, pêcheuses de poissons, chasseuses de grenouilles, buveuses de sang, mangeuses de fruits, consommatrices de nectars et de pollens, elles sont présentes à tous les étages de la forêt en adoptant des modes de vie souvent surprenants. Un chapitre est consacré à leur rôle dans la régénération forestière.</p

Monkey and dung beetle activities influence soil seed bank structure

We investigated the influence of Neotropical dung beetles on soil seed bank structure after primary dispersal by the red howler monkey (Alouatta seniculus). We collected seeds from soil samples (up to 15 cm depth) in defecation versus control areas and showed that seed number and diversity increased with monkey frequentation. Seed numbers decreased with depth. Seed viability, ascertained from seed coat integrity, decreased with depth and was higher in sites rarely visited by monkeys compared to control areas or sites frequently visited by monkeys. In field experiments, we incorporated plastic beads (1.3 – 5.8 mm) to fresh dung and monitored bead fate: the proportion of beads found in the soil top 10 cm increased with bead size and this effect was more pronounced in sites more frequently visited by monkeys. The same conclusions were drawn by comparing the beads found in the topsoil and the beads found deeper. We explored bead processing behaviour in several tunneller and roller species by performing experiments involving one species at a time. We showed that selectivity was highly variable: bead exclusion from dung reserves was higher in small than in large beetle species, higher for large than for small beads. Differences in selectivity between medium an