| dc.description.abstract | Bees display seemingly complex cognitive abilities as well as emotion-like states. Bees have been observed to show seemingly functionless behaviour in the form of repeated object manipulation - rolling wooden balls - that did not result in gaining food rewards in a laboratory context. The bees’ motivation to show such behaviour prompted to ask whether this was play. Play behaviour has been mostly reported in mammals and birds. Play is associated to intelligence and typically accompanied by positive affect. Using behavioural experiments, I present a detailed analysis of the phenomenon shown by bees: Bees rolled balls repeatedly, spontaneously and showed individual variation. Younger bees rolled more balls and showed an inverted U shaped activity similar to that commonly found in juvenile mammalian play and this differed from foraging activity. Males were found to roll balls for greater durations and distances compared to females. To test whether ball rolling was misdirected clutter clearing behaviour, corpses and artificial objects were presented both inside and outside the nest. Bees interacted with corpses and objects differently in form and between contexts, showing that the motivation to roll balls is not shared with clutter clearing. The manipulation of artificial objects was not limited to wooden spheres, but was also displayed on sponge cubes and rubber textured balls, showing that bees have a motivation to manipulate attractive objects in the environment. To check whether movable balls were inspected repeatedly in the prospect of eventually finding food, bees were presented with rewardless flowers. Bees showed more persistence in inspecting real flowers even if they never experienced them to be food-rewarding. Actions associated to foraging such as biting and proboscis extension, were displayed on real flowers but never on artificial objects, showing that bees were not searching for food in the balls. Bees showed a developed preference to environments or directions where ball rolling activity was previously experienced. This supports that ball rolling was rewarding in the bees. Is ball rolling rewarding because it provides any benefits? I tested whether ball rolling activity provides causally linked benefits to a novel problem solving and motor skill practice. Bees that rolled balls were found to have a competitive advantage at the total flower handling duration of the first flower of the novel foraging task. Specifically, this was seen when bees have to reverse out of the flower after feeding. This may reflect some practice of reversing (backward walking) while manipulating an object during ball rolling. In fact, no difference was found when entering the flowers, which requires forward walking. However, this advantage did not persist after the first flower. Differences between the two groups over experience depended on colony. | en_US |
