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Understanding the effects of neonicotinoid insecticides on bees is vital because of reported declines in bee diversity and distribution and the crucial role bees have as pollinators in ecosystems and agriculture. Neonicotinoids are suspected to pose an unacceptable risk to bees, partly because of their systemic uptake in plants, and the European Union has(More)
The species richness of flower-visiting insects has declined in past decades, raising concerns that the ecosystem service they provide by pollinating crops and wild plants is threatened. The relative commonness of different species with shared ecological traits can play a pervasive role in determining ecosystem functioning, but information on changes in(More)
A currently popular hypothesis states that the expression of carotenoid-dependent sexual ornaments and immune function may be correlated because both traits are positively affected by carotenoids. However, such a correlation may arise for another reason: it is well known that immune function is dependent on nutritional condition. A recent study has(More)
In many bird species, floaters are present on the breeding grounds in one or more years before they breed. There is increasing evidence that they have specific home ranges in which they search for information about current and future breeding opportunities. We investigated the role of prospecting in a migratory European starling (Sturnus vulgaris)(More)
There is compelling evidence that more diverse ecosystems deliver greater benefits to people, and these ecosystem services have become a key argument for biodiversity conservation. However, it is unclear how much biodiversity is needed to deliver ecosystem services in a cost-effective way. Here we show that, while the contribution of wild bees to crop(More)
Differences in growth conditions during early life have been suggested to cause long-lasting effects on morphology and quality of adult birds. We experimentally investigated the effect of early growth conditions on the expression of sexual ornaments later in life in male ring-necked pheasants (Phasianus colchicus). We also investigated the effects on immune(More)
A resolution model for evolutionary conflicts of interest is proposed. We assume that two conflicting parties originally have different evolutionarily stable strategies (ESS) with respect to a continuous variable, but that only one value of the variable is simultaneously possible. Individuals from the two parties meet in antagonistic encounters. The side(More)
Pollination is an essential process in the sexual reproduction of seed plants and a key ecosystem service to human welfare. Animal pollinators decline as a consequence of five major global change pressures: climate change, landscape alteration, agricultural intensification, non-native species, and spread of pathogens. These pressures, which differ in their(More)
To assess ecological consequences of bushmeat hunting in African lowland rainforests, we compared paired sites, with high and low hunting pressure, in three areas of southeastern Nigeria. In hunted sites, populations of important seed dispersers-both small and large primates (including the Cross River gorilla, Gorilla gorilla diehli)-were drastically(More)
Models of optimal clutch size often implicitly assume a situation with uniparental care. However, the evolutionary conflict between males and females over the division of parental care will have a major influence on the evolution of clutch size. Since clutch size is a female trait, a male has little possibility of directly influencing it. However, the(More)