Honey bees face a unique challenge as colder temperatures arrive and floral resources disappear. Unlike many other insects that hibernate or migrate, honey bee colonies remain active throughout the winter months. Their survival depends on remarkable adaptations and careful preparations made during warmer seasons.
Bees navigate this period by relying on communal strategies to ensure the colony’s continuity. These methods allow them to sustain themselves when external food sources are unavailable, revealing an intricate balance of resource management and collective behavior.
Stored Winter Provisions
Honey bees prepare for winter by accumulating significant food stores during warmer months. These provisions primarily consist of honey and pollen, gathered from flowering plants. Honey serves as the colony’s main carbohydrate source, providing the energy for warmth and metabolic activity throughout the cold period.
Pollen, stored as “bee bread,” provides protein, vitamins, and minerals. This nutrient-rich food is important for feeding the queen and developing larvae during brief periods of winter brood rearing. The balance of these resources is essential for colony health.
As temperatures drop, bees form a tight cluster inside the hive to conserve heat. The bees on the outer layer of this cluster insulate the interior, where the queen and brood are located. Bees within the cluster slowly consume their honey stores, generating metabolic heat to maintain a stable temperature, typically around 20-35°C (68-95°F) in the center of the cluster.
The cluster shifts position to access new honey stores. This slow consumption of stored honey and pollen sustains the colony through cold and resource scarcity. A strong colony can store 25-45 kg (55-100 lbs) of honey, generally sufficient for winter.
Sporadic Winter Foraging
While bees primarily rely on stored provisions, active foraging is minimal in harsh conditions. On milder winter days above 10°C (50°F), some bees may leave the hive for “cleansing flights.”
During cleansing flights, bees expel waste and may collect water, necessary for diluting stored honey and rearing winter brood. Rarely, if unusual floral sources are present, bees might collect small amounts of nectar or pollen.
This occasional activity does not significantly contribute to their winter diet. Energy expended on such flights is balanced against minimal resources. The vast majority of a colony’s winter sustenance comes from food stores accumulated before the cold season.
How Beekeepers Supplement Winter Food
Beekeepers ensure managed bee colonies have adequate winter food reserves. One common practice is leaving sufficient honey in the hive during autumn harvest for the bees’ use. This reserved honey acts as their natural winter food.
If natural honey stores are insufficient, due to poor nectar flow or excessive harvesting, beekeepers provide supplemental feeding. Sugar syrup, a solution of granulated sugar and water, mimics honey’s carbohydrate energy. This syrup is usually fed in late autumn or early spring.
Beekeepers may also provide pollen patties, flat cakes made from pollen substitutes, sugar, and other nutrients. These patties supply protein, vitamins, and minerals bees normally obtain from natural pollen. Pollen patties are useful if the colony needs to rear brood when natural pollen is unavailable. These interventions prevent starvation and ensure the colony remains strong until natural floral resources become abundant in spring.
What Happens When Food is Scarce
If a bee colony lacks sufficient winter food reserves, consequences can be severe, often leading to colony loss. The immediate risk is starvation, where bees run out of energy to generate heat and sustain metabolic functions. This can result in the entire colony perishing from cold and lack of sustenance.
Even if a colony does not starve, insufficient food can lead to a weakened state. Malnourished bees may have compromised immune systems, making them more susceptible to diseases and parasites. A weakened colony might struggle to rear new bees, leading to a population decline.
For wild bee colonies, winter food scarcity is a natural selection event, where only the strongest colonies survive. In managed beekeeping, food scarcity often results in significant winter mortality, necessitating beekeeper intervention to prevent colony collapse. A colony barely surviving winter due to lack of food may emerge in spring too small or weak to thrive and collect resources for the next year.