With over 2.3 million posts on Instagram, #savethebees is one of the most shared movements on social media.You won’t bee-lieve it, but bees have been on the decline in recent years, due to habitat loss, pesticides, and spread of parasites/pathogens.
([1] Source: Bartosz Brzezinski, CC BY-SA 2.0 License)
Most people don’t know that there are actually over 20,000+ species of bees in the world, although most are wild bees. It might be pretty reassuring to hear that honey bees won’t actually go extinct, because they’re managed by beekeepers. However, the risk still remains for the many species of wild bees.
So what’s a potential solution for this? We know that pesticides and pathogens are both major stressors for bees, but poor nutrition from loss of habitat plays an important role too. To maximize the benefits of bee-friendly plantings/habitat restorations, we have to find out what habitats and what flowering resources will attract bees.
That’s where the waggle dance comes in! Waggle dances are essentially how honey bees communicate information about the location of a food source to each other. These signals are a way for us to learn what kinds of resources honey bees will consider worth advertising to each other. Although honey bees may not always have the same preferences as other species of bees, eavesdropping on their waggle dances provides us with information that no other kinds of bees can give us. Because we would expect an overlap between the preferences of honey bees and other generalist bees, we can use the information we get to make predictions about how different habitats will affect other generalists.
But what really is a waggle dance? Well, it’s mainly made up of two components, a waggle run and a return phase.
([2] Source: Annabelle Teng)
You can think of it as an advertisement to other bees: Like, “ Hey! I just saw this super cool thing I think you should get! Here’s where it is!” Based on its angle where vertical represents the sun azimuth, bees know what direction they should fly in and and based on the duration of the waggle run, they know how far away the resource being advertised is.
So if we figure out what sites they are advertising when they’re dancing, we can get a sense of what habitats/resources they prefer. Until Margaret Couvillon and Roger Schürch started doing research on how to best map dances, very few researchers had tried to use locations advertised in dances to assess honey bee preferences or use mapped waggle dances to assess how abundant bee-attractive flowering resources are in different habitats. In the HMC Bee Lab, we are starting to map waggle dances to answer questions about honey bee preferences and foraging behavior, building on previous research. Keep on reading to learn more!
Some Applications of Waggle Dance Mapping
Previous studies have used waggle dances for a variety of questions. For example, an earlier study published in 2015 by Garbuzov et al. investigated the effects of a particular class of pesticides called neonicotinoids. They concluded that honey bees will forage from crop plants (Brassica napus) treated with neonicotinoids. However, only a minority of waggle dances advertised this pesticide-treated crop and only a minority of the pollen collected by their colonies came from it. They also found that colonies more than about 2 km away from Brassica napus fields almost never advertised or collected from those fields. That result gave helpful information about the risk of exposure to high doses of neonicotinoids.
Another study published in 2017 by Sponsler et al. examined whether urban or rural landscapes tended to have more bee foraging resources. They ultimately found that bees tended to dance more for rural landscapes and thus, determined that rural locations they studied generally have more abundant honey bee foraging resources. However, they don’t rule out the possibility of urban landscapes changing to become more bee-friendly in the future, in which case we expect to see more waggle dances advertising sites in the city.
Conclusion:
Honey bees communicate about the best food sources using waggle dances. In these waggle dances, forager honey bees relay information about distance and angle from the sun azimuth, which we humans can understand and map. By mapping them, researchers can answer many questions, including evaluating a specific habitat type for attractiveness to bees or even assessing the risk of pesticide exposure.
Further Reading :
An informative article about the diversity in species of bees!
https://beelab.umn.edu/pollinator-diversity
An easy-to-read webpage containing basic information about the waggle dance.
https://www.theapiarist.org/the-waggle-dance/
Information about the “Save the Bees!” movement. It contains information on what motivates the movement and possible policy changes the US could implement.
https://www.greenpeace.org/usa/sustainable-agriculture/save-the-bees/
A very in depth article about the waggle dance that references several scientific research papers on waggle dances.
https://www.beeculture.com/a-closer-look-waggle-dances/
Media Credits
[1] Public domain image by Bartosz Brzezinski: http://search.creativecommons.org/photos/08c8e907-9632-417f-b233-7639923fdac3
[2] Figure drawn by Annabelle Teng
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