Insectivorous birds have ecologically important effects on prey abundance, behavior, and evolution, and through top-down control birds indirectly reduce herbivory and promote plant growth. While several studies sought to characterize biogeographic patterns in top-down control by birds, variation in

Many plants have evolved nutrient rewards to attract pollinators to flowers, but most research has focused on the sugar content of floral nectar resources. Concentrations of sodium in floral nectar (a micronutrient in low concentrations in nectar) can vary substantially both among and within co-occu