Various reasons exist for losses of honey bee hives in winter. One of the primary factors that is most often overlooked is starvation. Starvation can affect your hives in a couple of ways. One condition is that the bees have so little food available remaining in the hive that when warmer days arrive, they leave. Another condition is actual starvation. Food supplies are completely exhausted and cooler weather confines bees to the hive resulting in death due to lack of food.
Based on the climate in your particular location, honey bees may cluster as early as September and remain in cluster as late as the following April. Although they will take cleansing flights on days when temperatures reach the mid 50’s, there may not be any available external resources for them to collect or consume. This leaves them with only the resources they were able to store in the hive prior to the end of the fall nectar flow. The available winter supply is directly impacted by the amount of honey that may have been collected by the beekeeper at the end of the season. Care must be taken to leave sufficient supplies for the bees winter needs. In warmer southern climates, this may be only 30 pounds, while in colder climates the need may exceed 60 pounds of honey. The bee keeper who is too aggressive with their end of season harvest, must be prepared to step in and provide supplemental feeding.
Supplemental feeding can be in the form of honey, sugar syrup, fondant, and pollen patties. One challenge with supplemental feeding is the behavior of the bees when they are in a cluster. Bees have a tendency to move vertically within the hive and not horizontally. Colder temperatures motivate bees to stay in more organized clusters. This means that honey and/or pollen stored on the outside edges of the frames may actually be untouched even as the bees struggle to maintain proper nutrition. This also increases the difficulty of providing supplemental feeding. You can add it, but it will do little good if the bees won’t break cluster to go and consume it.
In warmer climates, some species of trees may break dormancy and start to provide more organic nutrition during late winter/early spring. However, beekeepers cannot be lulled into a false sense of security. Many times colonies will begin to increase brood production exponentially as they approach spring. The effect of this is the further stress on remaining food stores. The rapid production of brood may easily outpace nutrient availability. Failure by the beekeeper to intervene by providing supplemental nutrition can lead to partial or even total colony loss due to starvation. Hive inspections on warmer days during the winter months can help to gauge the needs of each individual hive so that drastic shortages never develop.
Even the commitment by the beekeeper to provide supplemental feeding does not resolve all of the concerns. As mentioned above, the behavior of the bees as well as the prevailing weather can both have positive or negative effects on the success of each hive. The key to resolving this problem lies in the prevention of the problem developing. One of the most amazing things about the hobby of keeping honey bees, is of course the honey. However, care should always be taken to remember that bees make honey for themselves and the survival of the hive, not for us. Beekeepers should always be extremely cautious during any harvest during the fall. Along with an excess of caution in the fall, the hives should be monitored if possible during the winter so that any needed intervention can be taken in a timely manner. If it is needed, supplemental feeding should be provided during those rare warmer days when bees are exhibiting enough activity that they will actually access the feed.