Honey bees, like many insects, exhibit adaptations to endure winter’s cold temperatures. Unlike some animals that enter a hibernation state, honey bees remain active within their hive, collectively working to survive. This collective effort allows the colony to maintain a regulated environment, ensuring survival until warmer weather returns. The common perception of a dormant hive during winter belies the intricate activities occurring inside.
Winter Survival Strategies
Honey bees employ strategies to generate and conserve heat. When outside temperatures drop below about 57°F (14°C), honey bees form a compact “winter cluster” inside their hive. This cluster consists of two distinct layers: a dense outer mantle and a looser inner core. The outer layer of bees packs tightly together, facing inward, creating an insulating barrier by trapping air within their hairy bodies, which minimizes heat loss from the cluster.
Inside this insulating mantle lies the core, where bees are less densely packed and move more freely. Bees within the core generate heat by rapidly vibrating their flight muscles without moving their wings, similar to shivering. This muscle activity burns calories, producing warmth. The cluster’s core temperature is maintained at about 80-93°F (27-34°C), even when external temperatures are well below freezing. Outer layer bees rotate periodically into the warmer core, exchanging places with those inside, ensuring no individual bee becomes too cold.
The primary energy source for heat generation is stored honey, consumed throughout winter. A strong colony may consume 30 to 100 pounds of honey, depending on the cold’s length and severity. Bees typically avoid defecating inside the hive. On warmer winter days, when temperatures rise above about 50-55°F (10-13°C), bees take “cleansing flights” outside to expel waste, preventing buildup and contributing to colony health.
Life Inside the Winter Hive
The internal dynamics of a honey bee colony change during winter. The colony’s composition shifts, notably with the absence of male drones. As winter approaches, worker bees typically evict drones from the hive because they do not contribute to heat generation or foraging and consume valuable resources. This conserves limited honey stores for the queen and worker bees, essential for the colony’s continuity.
The queen bee reduces or ceases egg-laying during the coldest parts of winter. This reduction in brood conserves energy and resources. The worker bee population also changes, with a special generation of “winter bees” emerging in the fall. These winter bees have larger fat bodies and a longer lifespan, living for several months compared to the mere weeks of their summer counterparts. Their role is to keep the queen warm and the hive functioning.
The winter cluster slowly moves within the hive, shifting to access new honey stores. This movement is typically upwards and sideways, following available honey. Despite internal activity, overall activity levels are reduced compared to warmer months. The collective effort of worker bees to maintain warmth, manage food consumption, and keep the hive clean allows the colony to survive until spring, when foraging and brood rearing can resume.