Why do honey bees abscond in the fall?
Absconding is the term used when a colony of honey bees leaves its home in search of another. It is not the same as swarming. When a colony swarms, it splits in two parts: one part stays in the old home and one part finds a new home. Swarming is a form of reproduction. When a colony absconds, however, the entire colony leaves together and finds a new home—there is no increase in the total number of colonies.
I’ve heard many reports of absconding honey bees during the last month, both locally and from beekeepers in other parts of North America. But why would honey bees abscond right before winter?
Absconding is not well understood
Absconding is another of those honey bee behaviors that isn’t completely understood, but we can draw some conclusions based on repeated observations. Usually at least one of the following conditions exists in a hive before a colony absconds in the fall:
- There is a severe nectar dearth resulting in a shortage of stored food
- The hive has been heavily invaded by predators such as ants, yellowjackets, wax moths, or small hive beetles
- There has been excessive disturbance from interlopers such as skunks or beekeepers
- The hive is extremely hot due to the weather or severe overcrowding
In general, the environmental conditions in the hive became too stressful for the bees. Somehow they sensed they had little chance of surviving in the present circumstances and decided to leave.
Absconding is a process
Much like swarming, absconding is a process. Preparations are made well in advance of “moving day.” Usually the queen ceases to lay eggs and slims down in preparation for flying, foraging stops, scouts begin searching for a new home, and honey stores are used up.
By the time a beekeeper discovers an empty hive there is usually nothing left but wax comb. Comb left clean and neat usually indicates the bees left due to a nectar dearth and impending starvation. Comb that is shredded and irregular may have been damaged by robbing bees or yellowjackets. And comb ruined by small hive beetles or wax moths is often completely destroyed and full of feces and cocoons.
A fall absconding honey bee colony has virtually no chance of surviving the winter. The bees have no comb, no honey, no nectar source, no pollen source, and no time. They left their home because they didn’t know what else to do.
If you can catch such a colony, you may be able to save them by heavy feeding of honey, syrup, and pollen. But don’t put them back where they came from unless you can determine what was wrong and correct it. Otherwise, they will simply abscond again.
But is it really absconding?
An important issue, however, is whether the bees absconded or collapsed from Varroa mites. The result can look very similar, but more often than not, Varroa mites are the culprit. Please read “Absconding bees or death by Varroa?” for the details.
Honey Bee Suite