Of all the challenges faced by bees – and beekeepers – the topic of “overwintering” is one of the most commonly discussed. Even without our help, bees across the country manage to survive the cold winter months, which speaks to their incredible planning and resilience. But there are also a few things we can do to help them including, in some cases, the avoidance of our own “meddling” (for example, being a tad too eager to get our hands on honey!)
What Bees Do
To achieve their success, a considerable number of factors need to align to support the bees. Virtually all of this is down to preparation with a little help often provided by the beekeeper. Here are just a few of the details of how bees survive the winter.
Through the summer and into fall, the bees focus on building the essential honey reserves they will need for the winterIng in the fall, the workers kick drones out of the hive since they don’t help in any meaningful way and simply consume resources. The creation of brood is reduced, since every new bee is just another mouth to feed. The bees that enter the winter are, reasonably enough, called winter bees (sometimes “fat bees”) and have a different physiological makeup to summer bees. The life span of surviving winter bees is measured in months, as compared to the 6 weeks or so for regular worker bees in the other seasons. The colony maintains the temperature of the queen by forming the winter cluster.
Kicking Out the Lazy Ones
An early sign that your bees are preparing for winter will be the eviction of drones. These are worker bees kicking out their brothers!
They don’t hold back, as illustrated in this video.
Forming the Winter Cluster
Bees have several ways to combat the cold weather. But the most effective is the winter cluster, an incredible achievement of collaboration to huddle around the queen for the entire winter to keep her warm.
By forming the winter cluster, it's not just the queen that stays warm. Workers toward the center of the cluster receive the benefits and, as the cluster revolves, all the workers take their time on the outskirts of the cluster.
Access to Honey for the Winter Cluster
To have any chance of getting through the winter, bees need honey. Lots of honey. Through the winter, the cluster will wind a path around the hive, consuming honey reserves built through the summer and fall. The positioning and availability of honey is important and many a colony has starved to death with honey in the hive, but just out of reach of the cluster.
During warmer winter days, the cluster may become a little less compact and, on days with sufficient warmth, bees may leave the hive and stretch their wings, both figuratively and literally. This is a potential opportunity for the cluster to jump from one area of the hive to another. As the cold returns, the cluster will reform.
But if the cold days extend for a long period as is common in many areas of the country, especially in the north, this opportunity to regroup is not available to the cluster. In this situation, the cluster can survive if it can move over a path within the hive that always covers honey reserves. If the cluster is “stranded” in a part of the hive where honey runs out, it will not have the option to jump across to another area with honey, since the cluster must be maintained in the cold.
This is where beekeepers may experience the sadness of a lost colony, even though honey reserves lay undisturbed elsewhere in the hive.
The amount of honey required will differ, depending on the harshness of the winter. In warmer climates, for example in the US south, 50 lbs of honey may sustain the colony for the brief winter. However, in the north and in Canada much more honey may be needed, as much as 150 lbs in extreme conditions. That’s a great deal of honey.
How Beekeepers Can Help
When Possible…Leave Alone
Wherever possible, it is better to let the bees take care of themselves. They have a natural disposition to do so, honed over millions of years. So when they kick out the drones, ease up on the production of brood and form the winter cluster, it’s all part of an elaborate plan that has served them so well, for so long.
But if there are non-invasive ways to help them, then many beekeepers will consider doing just that. Let’s look at some ways beekeepers can help.
Leave Honey Reserves
It is possible to analyze and calculate and come up with many reasons you can and should take honey from your bees in their first year if they build strong reserves of honey. But a first-year colony is an unknown quantity, as is the coldness of the upcoming winter.
So we prefer a simple rule – don’t take honey from your bees in their first year.
Yes, there will be many who argue that this is overly conservative and will take moderate amounts of honey, while still expecting to see their bees survive the winter. But is it worth it? Is honey so important that this is necessary, in that vital first year for the colony?
Because there are so many variables at play we like the simplicity of “no honey in year one”.
Moisture
The threat of moisture can be a significant threat to bee’s survival chances in the winter. This is not related to rain (that’s a separate topic, with implications for the cover and slanting of the hive).
Condensation within the hive is caused by warm conditions created by the cluster and the low ambient temperature. This is a perfect combination to create condensation – lots of it.
In very bad situations, the bees might be “rained on” (on a perfectly dry day) when water condenses and then falls onto the cluster.
Resolving this can be a fine balance between ensuring the hive is ventilated vs. ensuring cold air does not enter the hive.
An aid to this issue is the use of “wicking” materials, such as a burlap sack or wood shavings, which do a fine job of absorbing moisture.
Temperature
The winter cluster does an amazing job of protecting the queen, including keeping her in a space that stays warm. Assuming they have sufficient honey reserves, bees can take care of themselves well, even in very low temperatures.
Perhaps the biggest challenge isn’t so much the external temperature but the effect of strong winds. In the winter, a strong wind can ensure the cold air finds every nook and cranny. In positioning your beehive, you have hopefully placed it in a position protected from strong winds, regardless of the season.
Although rarely necessary other than in very cold climates, hive wraps can be purchased, to help retain the heat.
The Objective
At the highest level, it’s straightforward.
As the cold weather arrives, bees stop foraging and hunker down for the winter. From that point forward they stay warm in the confines of the hive, throughout the winter. When the weather warms they appear and eventually start foraging again.
The aim is simply to survive the winter.
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