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This study provides evidence that a neural system extending from the preoptic region to the ventral tegmental area (VTA) of the midbrain is important for the normal expression of maternal behavior in lactating rats. In the first experiment, bilateral electrolytic lesions of the VTA severely disrupted the maternal behavior of postpartum rats. In the second(More)
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)
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)
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)
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)
In altricial birds, growth rates and nestling morphology vary between broods. For natural selection to produce evolutionary change in these variables, ther must exist heritable variation. Since nestling traits are not any longer presents in parents, traditional offspring-parent regressions cannot estimate heritabilities of these. In this study, a partial(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)
Female pheasants may base their choice of mates on the expression of male ornaments such as the red chin wattle and the length of the spurs. Both these ornaments are predicted to be sensitive to access to carotenoids (and vitamins). Moreover, because carotenoids also enhance immune function, it has been suggested that there is a trade-off in the use of(More)
1. Environmental changes may not always result in rapid changes in species distributions, abundances or diversity. In order to estimate the effects of, for example, land-use changes caused by agri-environment schemes (AES) on biodiversity and ecosystem services, information on the time-lag between the application of the scheme and the responses of organisms(More)