Harsh March

A Minnesota beekeeper checks his hive and finds plenty of bees and ample stored honey. Shortly afterward, cold weather set in for several days. Two weeks later, he finds the bees in the hive are dead even though the hive still holds plenty of honey. March is often the harshest month for honey bees. Bee populations are growing; the increasing population of bees requires a lot of food; the hive's food stores are rapidly diminishing; and there are not many flowers blooming for bees to forage. On warm days, worker bees may expend more energy searching for food than they would consume if they remained in the hive. Also, when there is brood in the hive, the bees must warm the brood nest to 95 degrees Fahrenheit, requiring the consumption of honey to generate heat. The most likely cause of the death of the Minnesota bees is starvation. Starvation is easy to identify; the beekeeper finds the dead bees clustered with dead bees head-first inside empty cells as in today’s photo. Often, ample stores of honey surround the dead, starved bees.

In starvation, here's what typically happens: The bees expand their winter cluster on warm days and contract the cluster on cold nights. On warm days the bees eat the stored honey surrounding the cluster. Then, when outside temperatures fall, the cluster contracts leaving a ring of emptied cells surrounding the bees. If the winter colony has no brood, the cluster may move about the hive. However, if there is brood present, the clustered bees will not move away from the brood. During a prolonged period of cold weather the bees remain tightly clustered, and they can't move the few inches to the stored honey. Because the colony shares food, all of the bees die when the colony runs out of food that they can access. If beekeepers detect a hive is short of food stores in late winter, they can provide emergency feeding of dry sugar or fondant candy.

--Richard