The Bees in Winter
By Al Cosnow
(Reprinted from the Grapevine, Winter 2016)
Probably the most common question that people ask a beekeeper in our climate is, “What happens to the bees in winter?” And they suggest, “Do you bring them inside?” or “Do they hibernate?” or “Do they die?” No, none of the above. Nor do they migrate south, as one person speculated. Well, for sure I don’t bring them inside–I don’t want to even think about that! And they don’t die, at least not if things go reasonably well. In fact the honey bee is the only social insect in our northern climate whose colonies can live through a severe winter, unlike bumble bees, wasps, and ants, whose colonies die out at the end of each season. That is, although there is attrition of workers during the winter, the honey bee colony as a whole survives, and it is the colony that counts, not any individual. Except, of course, the queen–we’ll get to her in a bit.
What happens is that the hive (that is, the white wooden structure the bees are kept in) remains all winter, right where it stood all summer, with the bees inside. They are not hibernating in there, not in the usual sense of going into a deep winter-long sleep like bears or reptiles. But when the temperature falls to about 45°F, they do stop flying out. The workers, twenty thousand or more of them–the workers are all female, although sterile–form a cluster inside the hive with the queen, their mother, in the center. (Earlier in the autumn they had already driven their brothers, the drones, out of the hive to perish. More about them later). Again, it is not a real hibernation. If the temperature at any time goes much above 45°F for a few hours, even in January or February, the workers will break the cluster and move around inside the hive, and at least a few of them will fly out.
Although one cannot see any activity from outside of the hive, there is a lot going on inside all winter. When they are in the cluster, with the all-important queen in the center, they vibrate their bodies constantly to create warmth. Many of them die and fall to the floor of the hive from all this expenditure of energy. Even if it is below zero outside, the center of the cluster, where the queen is, will remain at 90°F. Often if there is snow in front of the hive entrance, it will be melted by the warmth coming out. It takes a lot of energy to produce that vibrating and heat. The beekeeper must make sure that, after harvesting the season’s honey, he has left plenty behind for the bees to eat; they definitely need the calories. In this northern climate, at least 60 pounds of honey must be present in the hive at the end of the season to bring the colony through the winter.
During the occasional brief warmups in the winter, and especially as soon as there is the first real spring thaw, there is work to be done. First of all, the many workers who have died during the winter and fallen to the floor of the hive must be removed. One by one, but in large numbers, individual survivors can be seen dragging their dead sisters outside and dropping them on the ground in front of the hive, or even picking them up and flying with them to drop them several yards away. Also, since the workers never excrete their wastes inside the hive, they now take the opportunity to fly out in great numbers to clear themselves of their liquid yellow defecation. If the beekeeper happened not to be present to see this phenomenon, he will surely know that this cleansing flight took place if there was snow on the ground at the time, because when he returns, the snow will be covered with “yellow rain.” And he is glad, because it tells him that the colony has survived the winter.
There is one more thing the workers must do during those brief early spring warmups: All winter long they have been eating nothing but honey, and they are understandably thirsty. Many of the workers, after ridding themselves of their wastes, go out to collect water, often from melting snow, to drink and to carry back to the hive to share with their sister workers and the queen. The queen is the only fertile female in the colony, the mother of all those thousands of workers. Around October she had paused in her egg-laying and had done nothing all winter but rest in the center of that nice warm cluster surrounded by her daughters, who were feeding her the honey they had gathered and stored last year. Queen honey bees are entirely helpless–they can’t even feed themselves. But now she recommences her laying, fortified by the pollen the workers have started to feed her, the pollen that they stored last year and which is the important protein source she needs to produce those eggs. Soon there will be more pollen to provide protein, fresh now, from early spring flowers such as crocus and the little blue squill that blooms all over these suburbs. By early May, she will be producing a thousand eggs a day to build back the numbers of workers lost to attrition over the winter and to replace the drones that had been driven out in the fall.
Thus another season begins, as it has done, again and again for millions of years.