Honey Bees Get Hangry Too
Baton Rouge, LA. Clover is an important early spring food source
for honey bees in most regions of the U.S.
(Photo by Mandy Frake, ARS)
If you have ever been hangry (a portmanteau for hungry and angry), then you know what it is like to be irritable, bad-tempered, or easily annoyed. While being hangry may seem like an excuse for unpleasant behavior, research shows that hunger can cause shifts in our hormones, brain processes, and nervous system that result in negative emotions like anger.
According to a recent study, honey bees, like humans, may also experience hanger when they do not get enough nutrients. Pollen scarcity and nutritional stress are major issues that beekeepers are tackling to protect their hives.
“If honey bees are not getting enough pollen, which is one of their main sources of protein and an essential part of their diets, then it can lead to colony stress and defensive behaviors in bees,” said Elizabeth Walsh, ARS Research Scientist at the Honey Bee Breeding, Genetics, and Physiology Research Unit in Baton Rouge, LA. “Changes in colony defensiveness are of particular concern to beekeepers as increased defensiveness also increases safety risk of personnel.”
To better understand honey bee behaviors and to help beekeepers manage their hives, Walsh and the research team, including ARS scientists from both the Baton Rouge research unit and the Pollinator Health in Southern Crop Ecosystem Research Unit in Stoneville, MS, conducted a 5-week field study to simulate a pollen dearth, or shortage, in an apiary.
Baton Rouge, LA. (Photo by Mandy Frake, ARS)
“We found that honey bees who did not get enough pollen (the experimental group) became more aggressive than the honey bees who received enough pollen (the control group) throughout the study,” said Walsh.
Walsh added that the study was more than just observing honey bee behaviors. The researchers found that honey bees in pollen-poor conditions also showed physiological changes throughout the study. In particular, the pollen-deprived honey bees had smaller glands and different fat and sugar levels, which are signs of stress. The expression of some genes linked to aggression also was changed in these honey bees.
As beekeepers are concerned about pollen scarcity and nutritional stress, Walsh and the researchers believe that these research findings will help develop best management practices.
“Ultimately, this study shows that both researchers and beekeepers must find ways to evaluate how bees perform in changing environments in order to form best management practices while ensuring beekeeper safety,” said Walsh. – by Jessica Ryan, ARS Office of Communications