EAGER: Nutritional landscapes, physiological ecology & mechanistic drivers of bumble bee population dynamics

Bees play essential roles as pollinators of a wide variety of plant species, including for many of the most nutritious human food crops. However, we are only beginning to understand how, in turn, bee populations are limited by the availability of nutrients they obtain from pollen and nectar from flowering plants. This project examines how wild bumble bee populations are impacted by floral resource availability, focusing on a life stage (spring nesting) wherein bees are particularly sensitive to food resources.

A combination of fieldwork and laboratory experiments will be employed, with the former focusing on wild bee population dynamics and the latter designed to more directly test how food availability impacts bee survival and reproduction. Undergraduate students at a Hispanic Serving and Minority Serving Institution will participate in the research and be mentored to support their careers in science.

The field research will take place in the Sierra Nevada Mountains, and brochures for National Parks and Forests will be generated to inform the public and land managers about bumble bees, their nutritional needs, and site-specific floral resources. This project will reveal the specific nutritional challenges faced by native pollinators in order to reveal the most effective avenues for promoting pollinators and agricultural sustainability.

Nutritional regulation of population dynamics is a central focus of ecology, and yet the nature of this regulation can be difficult to elucidate because organisms and their food resources are often highly variable across space and time. This project uses wild bumble bees of the Sierra Nevada Mountains as a model system for identifying how pollinator populations are regulated by the availability of nutrients from floral rewards (nectar and pollen).

The project uses controlled laboratory experiments that manipulate food availability, and resulting vital rate responses, to parameterize a demographic model for bumble bees. In parallel, it examines relationships between wild bee population dynamics (inferred from genomic data) and floral resource availability to assess predictions from the model. Together, these components will advance the overall goal of integrating nutritional and physiological ecology to reveal the drivers of bee population dynamics across fluctuating resource landscapes.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.