Stroke patterns of a bumblebee at 3,250m
(green) and simulated 8,130m (blue).
The lower- altitidue strokes are shown on
both sides of the insect for comparison.
Source: Dillon and Dudley, Fig 2.
Dillon and Dudley analyzed film of the bees to figure out how they stayed aloft.. They found that the bees extended the range of their strokes. This is as opposed to increasing the rate of beating, which is the strategy for example used by water polo players to lift themselves out of the water. Dillon and Dudley do not speculate why the bees follow this strategy.
As for the significance of the extra capacity, they note that their test only asked that the insects get airborne. In the wild, the bees might need this ability to fly higher, or to maneuver while loaded, to evade predators.