Bee pollination increases yield quantity and quality of cash crops in Burkina Faso, West Africa.

Mutualistic biotic interactions as among flowering plants and their animal pollinators are a key component of biodiversity. Pollination, especially by insects, is a key element in ecosystem functioning, and hence constitutes an ecosystem service of global importance. Not only sexual reproduction of plants is ensured, but also yields are stabilized and genetic variability of crops is maintained, counteracting inbreeding depression and facilitating system resilience.

Determinants of stingless bee nest density in lowland dipterocarp forests of Sabah, Malaysia.

We measured the nest density of stingless bees (Apidae, Meliponini) in undisturbed and logged-over dipterocarp forests in Sabah, northern Borneo, and evaluated hypotheses on proximate factors leading to the observed variation: population control mediated by (1) nest predation, (2) limitation of nest trees, or (3) food limitation. Per-area nest density varied twentyfold across 14 forest sites and was significantly affected by locality, but not by the degree and history of disturbance. Nest density was generally high in sites located in the Sepilok Forest fragment (mean 8.

Arboreal ants as key predators in tropical lowland rainforest trees.

Ants numerically dominate the canopy fauna of tropical lowland rain forests. They are considered to be key predators but their effects in this regard have only rarely been studied on non-myrmecophytes. A conspicuously low abundance of less mobile, mainly holometabolous arthropods like Lepidoptera larvae corresponds with ant dominance, while hemimetabolous highly mobile nymphs occur regularly and in large numbers in the trees.

Alternative life cycle strategies in the West African reed frog Hyperolius nitidulus: the answer to an unpredictable environment?

The West African reed frog Hyperolius nitidulus, mainly known for its extraordinary aestivation behaviour and physiology, is able to vary its reproductive strategy in response to environmental conditions. We found indirect as well as direct evidence for individuals not following the generally assumed one year-one generation life cycle including an extended aestivation phase during the dry season, but leading very short lives for only a part of that rainy season in which the frogs were born. Second-generation frogs (males and females that reproduced in the season in which they were born) were significantly smaller than all other adults and their egg diameter was reduced.