Nutritional complexity and the structure of bee foraging bouts

How foragers cope with complexity in both needs and resources is a major question in behavioral ecology. When faced with nutritionally diverse resources, or when foraging for offspring with divergent nutritional needs, animals must meet the challenge of how to structure their foraging bouts, including what resources to forage for and in what order (how) to collect them. We investigated how nutritional variation in resources and requirements shapes the structure of bumble bee foraging bouts. Bumble bee workers collect 2 nutritionally distinct resources for consumers with different nutritional needs, floral nectar (largely carbohydrates) for their own needs and that of larvae, and pollen (largely protein) that is used primarily by larvae. We maintained colonies of the Eastern Bumble Bee (Bombus impatiens) in the laboratory on either protein-rich or protein-limited diets and assessed bees’ foraging bout structure on artificial flowers that offered low, medium, or high ratios of pollen to n...