COS 26-6 - Leveraging RFID technology to track early spring bumble bee queen foraging

Abstract: Bumble bee queens initiate new nests independently each spring, at which time they solitarily carry out all tasks related to larval rearing and nest maintenance. This foundational stage of the bumble bee life cycle is thought to be particularly sensitive to environmental stressors, which may help explain national and global declines in bumble bee populations. The colony founding stage and the factors that limit nesting success, however, remain severely understudied. In the summers of 2021 and 2022, we piloted a project to produce the first-ever continuous records of bumble bee queen foraging activity, as inferred by entrances into and exits from the nest. These data are a first step in identifying how early-nesting queens juggle the various demands on their time and energy in the earliest stages of the colony.

We developed a custom radio frequency identification (RFID) system to continuously record the comings and goings from the nest of three wild, trap-nested bumble bee queens. Queens were successfully recorded for a majority of their flight periods (approximately three weeks). Our results suggest that queens make an average of 10 foraging trips per day, each lasting an average of ~30 minutes, with the longest foraging trips occurring in the latter half of their flight periods. Queens ceased foraging within one week after workers were observed in the nests. Our results suggest that queens spend a substantial amount of their time and energy foraging for their young nests, but readily cease foraging once adult workers are present in the nest and capable of doing so in their stead.