Fruit Removal and Seed Predation in Two African Trees (Lannea acida and Lannea welwitschii, Anacardiaceae)

Fruit removal is an important component of plant fitness. The role of different frugivores in removal efficiency of two small-fruited trees, Lannea acida and L. welwitschii (Anacardiaceae), at Comoé National Park, northeastern La Cote d’Ivoire was investigated. At least 12 bird species, the red-legged sun squirrel (Heliosciurus rufobrachium), and four primate species consumed the fruits of the L. acida focal tree. Crop removal efficiency varied between 21% and 30% in two consecutive years. Up to 100% of the harvest and fruit fall were unripe fruits. Removal efficiency in L. welwitschii was higher (48.5%) despite lower visitation rates and only twospecies observed feeding. Most L. welwitschii fruits were removed during and after maturation but predispersal seed predation by H. rufobrachium left only 19.9% of the total crop to potential seed dispersal. In contrast, H. rufobrachium rarely fed on L. acida seeds. Sun squirrels consumed about twice (L. acida) to 10 times as much (L. welwitschii) fruits (seeds) per visit than birds. Primates removed 20-30 times more L. acida fruits and about 30 times more L. welwitschii fruit per visit than birds, but birds are able to compensate for lower food intake per visit by visiting a feeding tree more frequently. Birds and primates may, thus, both be important seed dispersers of Lannea seeds in terms of quantity. As a consequence of a large amount of unripe fruit fall and high pre-dispersal seed predation by vertebrates, the reproductive output of the focal trees during the study period in terms of dispersed seeds was low. Regeneration in L. acida and L. welwitschii might, thus, be source limited and dissemination limited, at least in certain years. Because interannual and intraspecific variation in fruit removal can be substantial, further research is required to determine long-term reproductive output in the two species

Brain architecture in the terrestrial hermit crab Coenobita clypeatus (Anomura, Coenobitidae), a crustacean with a good aerial sense of smell

<p>Abstract</p> <p>Background</p> <p>During the evolutionary radiation of Crustacea, several lineages in this taxon convergently succeeded in meeting the physiological challenges connected to establishing a fully terrestrial life style. These physiological adaptations include the need for sensory organs of terrestrial species to function in air rather than in water. Previous behavioral and neuroethological studies have provided solid evidence that the land hermit crabs (Coenobitidae, Anomura) are a group of crustaceans that have evolved a good sense of aerial olfaction during the conquest of land. We wanted to study the central olfactory processing areas in the brains of these organisms and to that end analyzed the brain of <it>Coenobita clypeatus </it>(Herbst, 1791; Anomura, Coenobitidae), a fully terrestrial tropical hermit crab, by immunohistochemistry against synaptic proteins, serotonin, FMRFamide-related peptides, and glutamine synthetase.</p> <p>Results</p> <p>The primary olfactory centers in this species dominate the brain and are composed of many elongate olfactory glomeruli. The secondary olfactory centers that receive an input from olfactory projection neurons are almost equally large as the olfactory lobes and are organized into parallel neuropil lamellae. The architecture of the optic neuropils and those areas associated with antenna two suggest that <it>C. clypeatus </it>has visual and mechanosensory skills that are comparable to those of marine Crustacea.</p> <p>Conclusion</p> <p>In parallel to previous behavioral findings of a good sense of aerial olfaction in C. clypeatus, our results indicate that in fact their central olfactory pathway is most prominent, indicating that olfaction is a major sensory modality that these brains process. Interestingly, the secondary olfactory neuropils of insects, the mushroom bodies, also display a layered structure (vertical and medial lobes), superficially similar to the lamellae in the secondary olfactory centers of <it>C. clypeatus</it>. More detailed analyses with additional markers will be necessary to explore the question if these similarities have evolved convergently with the establishment of superb aerial olfactory abilities or if this design goes back to a shared principle in the common ancestor of Crustacea and Hexapoda.</p

Socio-economical aspects of the exploitation of Termitomyces fruit bodies in central and southern Côte d’Ivoire: Raising awareness for their sustainable use

Objective: Picking fungal fruit bodies is a popular spare time occupation, as well as a source of income in many countries. In central and southern Côte d’Ivoire, fruit bodies of the genus Termitomyces are intensively harvested and sold by the local inhabitants. However, information on the dimensions of this trade and on other socio-economic aspects of the exploitation of these edible mushrooms is lacking. This study aims at (a) investigating the local populations’ knowledge about Termitomyces fruit bodies, (b) examining their utilization by identifying the actors involved of their exploitation and (c) determining the factors, explaining income differences among actors of this exploitation and fructification areas. Methodology: Some 240 persons from 12 villages belonging to two sub-ethnic groups (Baoulé and Abbey) were interviewed as to their attitude towards Termitomyces, using a structured survey questionnaire. Thus, we obtained information on Termitomyces fruit bodies’ availability, on indigenous knowledge and especially on the modes of utilization as well as on seasonal aspects of their trade.Conclusions:Interviewees had a solid knowledge of edible mushrooms in general and Termitomyces in particular. Four species were recorded in the study area (Termitomyces medius, T. letestui, T. cf. eurhizus and T. fuliginosus). The latter three species were considered as edible. These mushrooms are a key source of cash income, especially for women (traders) and the farmers (harvesters). However, only one species, Termitomyces letestui, is sold through a well-established trade route. Seasonal earnings within this trade route differed among actors, visited villages and phytogeographic zones. These fungi representing a typical Non Timber Forest Products (NTFPs) are menaced by unsustainable depletion. Overharvesting is jeopardizing their persistence as well as that of their dependant termite species. Raising an awareness that prevents their incurring the “tragedy of the commons” by developing a sustainable form of harvest is an essential prerequisite for their long-term preservation.Key words: Termitomyces; fruit bodies; Non Timber Forest Products (NTFPs); seasonal income; Sustainable use

Wind and sky as compass cues in desert ant navigation

While integrating their foraging and homing paths, desert ants, Cataglyphis fortis, depend on external compass cues. Whereas recent research in bees and ants has focused nearly exclusively on the polarization compass, two other compass systems—the sun compass and the wind (anemo) compass—as well as the mutual interactions of all these compass systems have received little attention. In this study, we show that of the two visual compass systems, it is only the polarization compass that invariably outcompetes the wind compass, while the sun compass does so only under certain conditions. If the ants are experimentally deprived of their polarization compass system, but have access simultaneously to both their sun compass and their wind compass, they steer intermediate courses. The intermediate courses shift the more towards the wind compass course, the higher the elevation of the sun is in the sky