The Arctic might seem an unlikely home for bees. Despite harsh conditions, including frigid temperatures and short growing seasons, a variety of insects have adapted to thrive. These bees play a unique role in sustaining the delicate balance of the Arctic ecosystem.
Identifying Arctic Bees
Arctic bees are a collection of species that survive in polar and sub-polar environments. The most common and well-studied among them are bumblebees, primarily belonging to the genus Bombus. One example is Bombus polaris, often called the Arctic bumblebee, which has a wide circumpolar distribution across regions like Arctic Alaska, Canada, northern Scandinavia, and Russia.
These bees exhibit a dense, insulating coat of hair, much thicker than their temperate counterparts, which helps slow heat loss. While their coloration can vary, Bombus polaris often has a black thorax with orange-yellow edges and an abdomen that is mostly orange-yellow with a black tip. Their larger body size also aids in heat retention in cold climates.
Adapting to Extreme Cold
Arctic bees have developed several adaptations to endure low temperatures and the brief Arctic summer. A primary mechanism for heat generation is shivering, where they rapidly vibrate their large flight muscles without moving their wings. This allows a bee like Bombus polaris to elevate its thoracic temperature significantly, sometimes up to 60 degrees Fahrenheit above the ambient air temperature. The dense fur then acts as an efficient insulator, trapping the generated heat close to their bodies.
These bees also employ strategies to utilize microclimates. On sunny days, queens and workers bask in direct sunlight to warm their bodies for flight. They also leverage the solar reflective qualities of certain flowers, such as the arctic poppy, which have conical shapes that can concentrate the sun’s rays, effectively acting as miniature magnifying glasses to help the bee raise its body temperature more quickly. Nesting sites are also carefully chosen, often in subterranean burrows, such as old mouse nests, which provide additional insulation and protection from the cold.
Their lifecycle is optimized for the short Arctic summer. Queens emerge from hibernation in mid-May, often feeding on early blooming plants like arctic willows. They produce large initial broods of larvae, around twenty in a clutch, which develop rapidly within about ten days. This accelerated development, combined with the heat produced by the queen and later by workers within the insulated nest, creates a nearly tropical environment for the growing larvae, allowing for the completion of at least two generations each year despite the limited warm season.
Their Vital Role in the Arctic Ecosystem
Arctic bees are primary pollinators for the unique flora of the tundra, making them important to the region’s biodiversity. Their ability to fly and forage at low temperatures, even below 10°C, allows them to pollinate plants when other insects cannot. This activity is necessary for the reproduction of many Arctic plants, including arctic willows, arctic poppies, and arctic roses, which depend on these bees for seed production.
The pollination services provided by Arctic bees support the entire Arctic food web. Healthy plant populations, facilitated by bee pollination, provide food for herbivores such as caribou and lemmings. These herbivores, in turn, become a food source for carnivores like Arctic foxes and wolves, illustrating a direct link between bee activity and the broader ecosystem’s health. For instance, some plants like monkshood have evolved flower shapes and sizes specifically adapted for pollination by bumblebees, highlighting the specialized relationships that exist. The success of only one queen per colony on average surviving the winter underscores the impact these bees have on the Arctic ecosystem.