By Amanda Puitiza
image – Russell’s site therusselllab.net
Many of us have likely heard or seen videos of the honeybee’s famous waggle dance used to communicate the location of food. For those of us forced to rely on Google maps to find out which way is even North, this sort of skill would be amazing to have. Well, it turns out that finding food can be more complicated than shaking your thorax and can depend a lot on the available food sources.
Dr. Avery Russell of Missouri State University is trying to figure out the mechanisms behind flexible foraging behavior in bees. In a rapidly changing environment, being able to roll with the punches is your best bet for survival. This means, for example, that when your food options are changed or limited, you can still successfully get some grub. By focusing on food-collecting behaviors in bees and manipulating their food sources (pollen-producing flowers), Dr. Russell and his students were able to learn more about this possible flexibility.
Do “hive” still got your attention?
Bees use two methods of collecting pollen from flowers: buzzing and scrabbling. Buzzing is generally used to extract pollen deep within the anthers, vibrating their flight muscles to shake the pollen out (Russell, Leonard, Gillette, & Papaj, 2016). Scrabbling involves using the legs and mandible to knock freely-available pollen onto their bodies (Russell & Papaj, 2016).
When the Russell lab exposed flower-naive bees to begonias (flowers with pollen that is tucked away) over several trials, bees switched between the two methods 20% of the time. When the team exposed bees to flowers with and without pollen, they found that pollen elicited scrabbling behavior but suppressed buzzing behaviors.
Using artificial flowers with hard to get pollen, the team also found that when pollen was scarce, buzzing was 52% more efficient at collecting pollen than scrabbling. The endgame is to get the most pollen possible, and bees appear to be experts at doing this right by switching between the two foraging methods depending on what types of flowers are available and their pollen accessibility.
“You can learn a lot of things from the flowers…” Abilene Mosher, Dr. Russell’s student found this out firsthand when she manipulated the chemicals that flowers give off to attract bees. Mosher dosed artificial flowers with tube-like anthers – flower structures that contain pollen – with various concentrations of anther chemicals from living common flowers and found that some of these chemical cues can generate buzzing behaviors, particularly at close range. It looks like the most fragrant wins this round!
“Pollen” it all together now.
Bees and flowers are on an evolutionary path together. Since they rely on each other for different things – bees get food from flowers and flowers get pollinated by bees – it makes sense that they have changed with the times simultaneously, or co-evolved. Although researchers are still working on the mechanisms flowers can use to modify bee interactions it is likely that flowers also show signs of flexibility. I am sure we can expect many more interesting discoveries from the Russell lab and others interested in these busy bees and the flowers they feed on!
Amanda Puitiza is a Peruvian-American scientist with a Master’s in Animal Behavior and Conservation from Hunter College. Her interests include the influence of sociality on behavior, behavioral plasticity, and the gut microbiome. She is also a great supporter of citizen science.
S3 (from SICB virtual 2021) Physical Methods of Behavior II: Ecological and evolutionary consequences of flexible foraging behavior for bees and flowers by Dr. Avery Russell; Complementary to S3: Physical Mechanisms of Behavior (Foraging): No trick anthers: buzz pollination behavior is elicited, but likely not manipulated, by anther chemical cues by Abilene Mosher et. al.
Russell, A. L., & Papaj, D. R. (2016). Artificial pollen dispensing flowers and feeders for bee behaviour experiments.
Russell, A. L., Leonard, A. S., Gillette, H. D., & Papaj, D. R. (2016). Concealed floral rewards and the role of experience in floral sonication by bees. Animal Behaviour, 120, 83-91.
Photo credit: The Russell Lab (https://therusselllab.net/research/)