The Habits of Honey Bees

February 1, 2012
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Have you ever hosted a backyard cookout and wondered why all the bees in the neighborhood suddenly found your fruit salad? Ever pondered how a hive produces that delicious honey you add to your tea? The answer lies in the fascinating habits of honey bees. Approximately 20,000 species of bees are found on every continent except Antarctica, and though many of them are solitary, the honey bee (Apis mellifera) can only survive as a member of a colony. Professor of Biology Hartmut Doebel and Senior Biology Major Heidi Wolff are taking a hard look into colony life at the urban apiaries on the rooftops of Bell and Lisner Halls to learn more about the habits and communication patterns of these insects that are so critical to our daily lives.

“Ok, ladies, don’t get cranky,” is a phrase Wolff often uses when working with the honey bees in GW’s urban apiary and honey bee lab. In any given colony, most of the 60,000 bees are female led by a single queen. Physically larger than the other bees, the queen lays up to 1,500 eggs in one day and as many as one million eggs in her relatively short life span of one to five years. She can defend herself, but otherwise is reliant on the colony to house, feed, and clean her and her brood.

Worker bees make up the largest population in the colony, and their moniker is well-earned. All females, these busy bees build and maintain the nest, construct the hexagonal cells of the comb by secreting wax from glands in their abdomens, care for the brood laid by the queen, defend the colony, and are responsible for venturing from the nest to gather pollen, nectar, and water. Drones, the only male honey bees, are unable to defend or feed themselves and exist only to mate with the queen and die. 

“Honey bees are beautiful,” said Wolf. “Being a part of a colony, they literally work themselves to death for the betterment of their family.

The Waggle Dance

In any large population, communication is essential and honey bees use one of the most complex languages of any species on earth: the waggle dance. Coined by Karl von Frisch who cracked the honey bee communication code—a feat that earned him the Nobel Prize in Physiology in 1973—the waggle dance is a series of movements the bees perform at precise angles in relation to the hive to tell their fellow colony members the distance and direction of food sources, water sources, or new housing locations.

According to Professor Doebel, the waggle dance is an extremely effective form of communication, as was demonstrated when he inadvertently left a frame of honey outside of the hive while inspecting inside. What followed surprised even him: he and the area around him was engulfed by bees from hives located elsewhere in the Foggy Bottom neighborhood looking for the honey.

“Worker bees from neighboring hives discovered the honey and reported back, ‘Food!’” said Doebel.  “I quickly replaced the honeyed frame back into the hive and, within 40 minutes, the neighborhood bees had left in search of other food. It was an amazing experiment to see the bees’ communication in action.”

Doebel is in the process of designing a new lab for the study of bee communication. During the coming months, the lab’s observation hive, which is fitted with a glass pane so students may monitor what happens inside, will be equipped with a camera that feeds to a live website. From this feed, students may observe the hive at any time and measure the angles and speeds of the bees as they perform the waggle dance.

“It’s a wonderful thing to have bees for my students to see and get excited about,” he said. “In our introductory biology classes, we plan to teach the students how to decipher the waggle dance. Once they master the dance, they will be able to calculate the precise location of food sources for the bees.”

Equipped with directions and locations from their waggle dance observations, the lab students will help Doebel create an area map of all the plant species within a mile radius of the GW apiary so they can determine the source of pollen and nectar that goes into the bees’ honey production.

Sweet Results

Though the bees work hard to make their colonies thrive, their activities produce sweet results for the rest of us. In the process of gathering pollen and nectar for their hives, they pollinate flowers—ensuring that plants reproduce and yield fruit and other products. This act is so essential to crop production that many apple, almond, and other farms in the United States bring honey bees into their orchards during pollination season to facilitate the process.

And let’s not forget about the honey! At its very basic, the tasty treat is made from nectar, but here are more juicy details: Worker bees draw nectar, a fluid of 80% water and 20% sugar found in flowers, through their proboscises and store it in their crops (small chambers in their digestive tracts). To give you an idea of how hard these bees are working, a honey bee has to visit between 150 and 1500 flowers before her crop is full. She then carries the nectar back to the hive where it is regurgitated into the honeycomb. Other worker bees then help to transform the nectar into honey by swallowing and regurgitating the nectar over and over, and by fanning their wings over the honeycomb, effectively evaporating water from the nectar and adding enzymes and protein to the oils and sugars in the nectar. The result is sticky, sweet honey that the bees eat in winter when flowers are scarce, and people harvest for use in cooking and medicine.

Part of Wolff’s research is to find out where GW’s bees are getting their nectar and pollen. Her study, Urban vs. Rural Apiculture: An Observational Study of Pollen Quality and Content, focuses on researching the differences between pollen collected by urban and rural apiaries.

“I’m performing three different analyses of pollen collected in the field: biodiversity of pollen, protein content of pollen, and pesticide presence,” explained Wolff. “As part of this study, I’ll use pollen color sorting to determine the biodiversity of pollen and Bradford Protein analysis to determine varying protein contents in different pollen samples.”

She’s also working with the USDA Agriculture Marketing Services Laboratory in Maryland to study the pesticide presence and content in the pollen samples, and is collecting samples from additional apiaries in D.C. and in rural Maryland.

“Though I’m still collecting data, I expect to find that urban landscapes contain a greater plant diet breadth for bees and decreased pesticide exposure as well in comparison to rural environments,” said Wolff. “If we prove this to be true, our results will support the idea that the urban environment may be a useful resource for bolstering healthier honey bee populations and lending support for the rise in urban agriculture and apiculture.”

What’s Buzzing on the Horizon

For Doebel and Wolff, the GW urban apiary project is just getting started. Thanks to a partnership with Founding Farmers restaurant, the apiary has gained six beehives on the roof of Lisner Hall and Wolff’s research is funded by a $5,000 grant. With the partnership now entering its second year, they are hoping that each hive will produce between 20 and 120 pounds of honey for cooking and small-production bottling by Founding Farmers. Wolff plans to continue her research at the master’s level after she graduates this spring.

“Beyond comparing urban and rural apiaries and analyzing the 'waggle dance', we have several projects going on to learn about social insects, honey bee health, and the effects of certain pesticides on honey bees,” said Wolff. “Dr. Doebel and I have similar intentions of teaching the community about our bees and what can be done to help them, as well as methods of bolstering native pollinators.”