Bumblebees' Energetic Foraging Choices for Optimal Sugar Collection
New research reveals intriguing insights into the foraging behavior of bumblebees, shedding light on their prioritization of collecting the most sugar from flowers in the shortest time. The study, focusing on one of the UK's common bumblebee species, Bombus terrestris, demonstrates that these industrious pollinators make decisions that maximize the amount of nectar sugar they return to their colonies every minute.
The study finds that bumblebees weigh the time spent collecting nectar against the energy content of the nectar. In other words, they opt to forage for nectar that may be harder to access, as long as the sugar content justifies the extra effort. This approach, characterized as "big-and-fast," is a departure from the more measured foraging strategy of honeybees, who optimize their individual energy expenditure for nectar collection, potentially extending their working lives.
Dr. Jonathan Pattrick, one of the report's joint first authors, notes, "As they forage, bumblebees are making decisions about which nectar sources will give the greatest immediate energetic return, rather than optimizing the energy efficiency of their foraging." This research, conducted initially at the University of Cambridge and now based at the University of Oxford, provides valuable insights that could inform the selection of flowers planted in field margins to support these crucial pollinators. It is also relevant for crop breeders aiming to create varieties that are more suitable for bumblebees.
The study, spanning six months, involved 60,000 behavioral observations of bumblebees, enabling precise estimations of their foraging energetics. Each bumblebee in the study was meticulously observed for up to eight hours a day without interruption. The research employed artificial flowers with different orientations and surface characteristics, allowing the team to measure the timing of bumblebee flights, energy expenditure, and nectar collection.
Dr. Hamish Symington, joint first author of the report, emphasizes the complexity of bumblebee decision-making despite their diminutive brain size, noting that bumblebee foraging involves more than a simple preference for higher sugar content in nectar.
The experiments showed that bumblebees exhibit adaptability in their foraging choices. When nectar sugar content was equal, they chose horizontal flowers over vertical ones. However, when vertical flowers offered significantly sweeter nectar, bumblebees exclusively foraged on them. When the sugar content difference was marginal, the bees demonstrated a trade-off, opting for easier access over higher sugar content.
These findings illustrate that bumblebees can make sophisticated decisions about their foraging behavior, optimizing the energy expended for collecting high-sugar nectar when the reward justifies it.
This research provides a deeper understanding of bumblebee foraging strategies, highlighting the remarkable complexities of insect behavior and underscoring the need for further exploration in this fascinating field.
#Bumblebees, #Pollinators, #ForagingBehavior, #InsectResearch, #NectarCollection
