Why so many starving bees?
It was a winter of starving bees. In the past few weeks I’ve heard countless tales of beekeepers losing all or nearly all their colonies to starvation. Many of their hives contained not a single drop of honey. Others had full frames of honey remaining, but the bees died anyway.
During cold weather, the bees cannot leave the cluster in order to find food. Oftentimes, honey stored just beyond the edge of the cluster is never touched. As the bees move upward, they consume the food the cluster encounters. The resulting pattern resembles a vertical tunnel through the stored food.
Movement within the hive
Warm periods during the winter allow the bees to move around and find more of the stored food. Sometimes the cluster may move toward one side of the box and eat the honey there. But after it becomes cold again, they are even further from the stores remaining on the other side of the box—which is why you sometimes see the dead cluster on one side or in one corner of the brood box.
A similar type of movement occurs in top-bar hives. Although the bees don’t move up, they may gradually move left or right. But if they eat their way to one end of the hive, they can’t turn around and traverse the empty combs to get to the other end. So they run out of food.
The cluster of bees won’t leave brood unattended, so even though there is very little brood in the winter months, it anchors the cluster to one spot. It seems like the bees would move freely inside their box, but instead, they are always attached to the nursery.
Bees move up in cold weather
Placing feed—especially hard candy—just above the cluster is very effective because that is where the bees are most likely to find it. In addition, heat from the cluster keeps that area warmer than the surrounds, so bees can move onto the candy without freezing.
A lack of honey may be due to over-harvesting, but it may also be due to paltry nectar flows or particularly long winters. Whatever the cause, feeding sugar can be a long, time-consuming, and expensive ordeal—but it may be the only way to keep your bees alive.
The photo below shows what starved bees typically look like. The bees—still in the shape of a cluster—all died head-down in a cell with their little butts sticking up in the air.
The signs are confusing
Please note, however, that adult bees with their heads down and butts up is a typical wintertime configuration and not a sure sign of starvation. According to Thomas Seeley, “Worker bees deep in cells, with heads down, are a normal part of a winter cluster. This is what the bees do to keep the insulating mantle of the cluster continuous, even where a comb slices through it. When a colony starves, we find lots of bees deep in cells, but they are not a sign of starvation.”
In other words, if food is nearby, the bees you see in the cells may simply have died of the cold. To determine the final cause of death, a beekeeper needs to evaluate the size of the remaining colony as well as the location of any remaining food stores.
Thanks to Jared Watkins for the great photo.
Honey Bee Suite