Let’s bee informed about honey bee foraging
There is something mesmerizing about watching bees at work! These little workers have been agriculturally critical to humans for thousands of years, and over this extended time, we have accumulated a wealth of research about their physiology and behavior. Here, we focus on honey bee foraging behavior, which provides us with a fascinating example of how the honey bee colony functions more as a superorganism than a population of individuals.
Honey bee foragers collect all of the nutritional elements for their colony, including nectar, pollen, and water. Water is sourced close to the colony and used to hydrate and cool the colony during hot weather. Research has shown that pollen foraging, a colony’s main source of protein, minerals, and vitamins, is directed by the colony’s current state. Pollen stores are vital for brood production and healthy development of young within the hive, and pollen foraging has been shown to be regulated by the presence of brood pheromone and young larvae in the colony, as well as the quantity of stored pollen. Nectar, on the other hand, is the primary source of carbohydrates and provides the necessary energy for foragers and the colony as a whole. Honey bees store nectar as honey and securing healthy supplies allows for strong colony maintenance and overwintering.
Contrary to pollen foraging, bees continue to forage for nectar regardless of the honey stores in the colony. However, plans in the colony are subject to change! Larval pheromones have been shown to transition the behavior of nectar-foraging bees to pollen foraging for a duration of time to meet a growing need of pollen in the colony.
It is also important to note that not all nectar and pollen sources are equivalent. Just as flowers physically differ, flowers provide varying types and levels of nutritional elements. Forager bees will often visit a buffet of different flower types to bring well-rounded sustainment back to the colony. Interestingly, bees base foraging decisions on the nutritional value of certain flowers and their own colony’s requirements.
Foraging preference studies have demonstrated that the highest criteria for foraging was nutritional content of protein and relative availability of resources, especially when the colony need was high (indicated by number of larvae). In one study, white clover (Trifolium repens) and then daisy fleabanes (Erigeron annus) were visited most frequently and accounted for the most collected pollen when colonies were given a diverse landscape of floral resources. The same study showed observations of peak foraging rates in the early afternoon and that foraging was highly dependent on temperature outside the hives. The high energy demand for flight muscle movements means that honey bees very rarely forage below 55 °F (13 °C) or above 100 °F (38 °C).
Honey bees are experts at efficiency determination, measuring their own spent energy to required work ratios in real time and relaying the best foraging locations to the colony on their return. They do this through the “waggle dance,” which is exactly what it sounds like! When worker bees return from optimal locations, they wiggle their bodies in a way that the other bees understand as both directions and distance to the best foraging location. What looks like an adorable dance is in reality a very precise method of communication. Angles and duration of these “dances” relay the direction and distance. Bees are showing us that dancing isnt’ just for after-work fun…it IS work!
While there are many factors that impact honey bee foraging behavior, it’s clear to see that honey bees are never blindly working. It’s been several centuries since Chaucer introduced the saying “busy as a bee,“ but, given all we know about bees, we should take this idiom on face value. Bees pursue directed work with decision-based efficiency rather than aimlessly buzzing around.