Bees exhibit intricate behaviors, many of which involve movement across various distances. These movements are fundamental to their survival and colony propagation. From daily flights to extensive journeys, bees show remarkable adaptations to navigate their environment and secure resources. Understanding these movements provides insight into their complex lives and role in ecosystems.
Distinguishing Bee Movement: Migration and Swarming
Migration and swarming are distinct bee movements. Migration is the seasonal movement of bees from one location to another over long distances, seeking food, nesting sites, or better environmental conditions. This movement is a seasonal event driven by external factors like resource availability or climate shifts.
Swarming, in contrast, is the natural reproductive process of a bee colony. A portion of the colony, including the old queen and worker bees, leaves the original hive to establish a new one. Swarms settle within a few kilometers of their original hive, making it a more localized dispersal than long-distance migration. This process is triggered by internal colony factors such as overcrowding or a decline in the queen’s productivity.
Drivers of Bee Migration
Bees migrate primarily due to environmental pressures affecting their access to food and living conditions. A primary driver is the pursuit of floral resources like nectar and pollen, which fluctuate seasonally. As flowering plants finish blooming in one area, bees travel to regions where new floral sources are available, ensuring continuous sustenance for the colony.
Climate shifts also prompt migration, as bees avoid harsh conditions like extreme cold in winter or excessive heat in summer. Such movements allow colonies to maintain an optimal temperature for survival and brood rearing. Habitat changes, including the loss of natural foraging areas due to human activity or agriculture, can also compel bees to seek new territories with better resources and nesting sites.
Navigational Strategies of Migratory Bees
Migratory bees possess advanced sensory abilities, allowing them to navigate vast distances with precision. Their internal compass system relies on the sun’s position, even when obscured by clouds or dense vegetation. Bees detect polarized light patterns in the sky, created by sunlight scattering, which provides a reliable directional cue for maintaining a consistent flight path.
Bees are also sensitive to the Earth’s magnetic field, using it as an additional navigational aid. This magnetic sense helps them determine direction and orient themselves within their hives and during foraging flights. It complements their sun and polarized light compass, providing a strong navigational system for their journeys. Olfactory cues, such as the scent of specific flowers or pheromones left by previous foragers, can also guide bees, particularly over shorter distances or within familiar foraging grounds.
Examples of Migratory Bee Species
While many honey bee species, like the Western honey bee (Apis mellifera), do not exhibit traditional long-distance seasonal migration, some Apis species do. The giant honey bee (Apis dorsata), found across southern Asia, is an example. Colonies of Apis dorsata seasonally migrate between highland and lowland nesting sites, covering up to 200 kilometers to exploit changing bloom patterns.
Certain solitary bee species also travel notable distances, though not always as seasonal migration. For example, the Euglossine bee, Euplasia surinamensis, has returned home from 24 kilometers away. Other solitary bees have traveled 14 to 20 kilometers with full pollen loads. Bumblebees, such as Bombus terrestris, forage within a shorter radius, often around 625 meters from their hive, but their movements still adapt to finding available floral resources.