Magnificent Winter Cluster


Cold bees increase the warmth inside the hive during winter’s frosty temperatures. Making heat makes bees hungry and they eat more to build their strength. The winter bees run through a constant loop when they get chilled. They condense their size by clustering to conserve heat, and certain bees, known as “heater bees,” spread themselves over the outside of the cluster like a blanket, and they speed up their vibration to increase the interior warmth.

It’s important the honey be nearby. Colonies can die if the honey is too far from the cluster. Many beekeepers have opened hives in spring and found colonies who died of starvation despite full honey stores just two combs away. If it’s too cold, the bees won’t cross into the cold zone to find more food. For this reason, many beekeepers who live in cold climates feed their bees sugar syrup in fall and dry sugar through the winter, so they have enough food to make it to spring.

Normally here you’d expect me to talk about the importance of extra fall and winter feedings to boost food stores. That’s logical, right?

Let’s stop right there and question something that doesn’t get talked about enough but is crucial to winter survival:  wall insulation.

Bees in the wild often choose hollow trees to live in. What’s the biggest difference in a human-made hive and a hollow tree? The thickness of the walls! In a human-built hive, most wood is a mere 3/4 inch thick. In a hollow tree, you’ll more often find 4 inches of thickness. That’s a BIG difference.

New research shows that well-insulated hives retain heat so well that the bees who live inside don’t even go into cluster in winter. What? That goes counter to most everything we are taught about winter bees — that as soon as the temp goes down to the 40s, they go into torpor and activity ceases. As the temperature increases the next day (or week), bees come out of torpor and eat more honey to rev themselves up again. Over and over, depleting their food supply enough that we hope they don’t starve and they make it to spring.

This cycle shows how honey stores get depleted. When bees constantly bounce between waking up or going into torpor over and over, more honey gets eaten. Thomas Seeley’s feral bee research says that bees who live in well-insulated hives (natural hollow trees) eat 4 to 7 times LESS honey than bees kept in human-built hives. That’s what I want for my bees — less work and that they conserve their honey not out of necessity, but by choice.

In winter weather the bees rotate from the warm inner cluster to the cold outer cluster and back. The colony needs plenty of bees so nobody is overworked. If there are too few bees going in to winter, they can’t maintain the steady warmth the cluster needs. Those overworked bees wear themselves out and die.

Going into winter I used to worry that my late swarms wouldn’t have time to raise enough bees to make a good size cluster and store a honey reserve. I used to merge small hives, knowing I was forfeiting one of the queens, but I never knew if that was right action on my part. Then I went through a phase where that didn’t feel right, so I let every hive, even the smaller ones, have a go at getting through winter.

I let every hive live or die on its own merits. That’s survival of the fittest and in this era of weak bees there’s much to be said for that. As a treatment-free beekeeper, I know that some hives won’t make it on their own. Surprisingly, even some of my smallest hives somehow made it through the winter. And the colonies that live in hollow trees on our farm, those bees always made it. Always. Even though they seemed to host a smaller size colony. Isn’t that interesting?

To be useful to the bees, give them hives that have more insulation capacity. That affects survival rates in a more positive manner.

Though I tend to be a hands-off beekeeper, I sometimes get very hands-on when a hive is almost-but-not-quite big enough and I know it won’t survive on its own. In that situation I combine two hives to make an even stronger one.

While many beekeepers split hives in spring to make more, I don’t believe this is correct. Allowing colonies to split themselves through swarming is a wiser choice because the size, quality of the departing queen, and perfect timing is left up to the bees. They always always always know more about what is right action than we do.

I’ve heard tales of hives with an extra Queen. I even saw a secondary Queen in one of my hives once. The primary Queen was the center of attention, but the secondary Queen was still alive and was probably going to stick around awhile longer. She wasn’t a threat and seemed to have taken up her station in the tippy-top of the upper box where she moved among the bees making honey.