Researchers train bumblebees to move a ball in order to access a sugar solution as a reward.
"Our study puts the final nail in the coffin of the idea that small brains constrain insects to have limited behavioural flexibility and only simple learning abilities."said Prof. Lars Chittka, project supervisor and co-author of the study.
Past research has shown that bumblebees can solve a wide range of cognitive tasks, but these tasks were similar to the bees' natural foraging routines, for example pulling strings to obtain food.
The new study examined behavioral flexibility to carry out more complex tasks that are not naturally encountered by bumblebees:
"We wanted to explore the cognitive limits of bumblebees by testing whether they could use a non-natural object in a task likely never encountered before by any individual in the evolutionary history of bees." said Dr Clint Perry, joint lead author.
The experiment required the bees to move a ball to a specified location to obtain a reward of food. The insects were first trained to know the correct location of the ball on a platform. Then, to obtain the reward, they had to move a displaced ball to the specified location.
To learn the technique, the bees were trained under one of three conditions:
- The first group observed a previously trained bee move the furthest ball to the centre to gain reward
- The second group received a "ghost" demonstration, where a magnet hidden underneath the platform was used to move the ball
- The third group received no demonstration, where they found the ball already at the centre of the platform with reward
The bees that observed the technique from a live or model demonstrator learned the task more efficiently than those observing a "ghost" demonstration or without demonstration.
"The bees solved the task in a different way than what was demonstrated, suggesting that observer bees did not simply copy what they saw, but improved on it. This shows an impressive amount of cognitive flexibility, especially for an insect." said Dr Olli J. Loukola.
During the demonstrations, the researchers placed three yellow balls at varying distances from the center. The "demonstrator" bees always moved the furthest ball to the centre, and always from the same spatial location, since they had been trained under conditions where the closer balls were immobile. Untrained bees were given three opportunities to watch a skilled bee perform the task in this manner.
In later tests, when these untrained bees were tested without the presence of a skilled demonstrator, bees moved the closest ball instead of the furthest ball, which they had seen the demonstrator moving. Interestingly, in another experiment, the bees also used a differently colored ball than previously encountered.
"It may be that bumblebees, along with many other animals, have the cognitive capabilities to solve such complex tasks, but will only do so if environmental pressures are applied to necessitate such behaviors." added Dr Loukola.
I wonder what's next? Could a bumblebee learn to play fetch? Probably yes!
Here's the abstract of the study:
We explored bees’ behavioral flexibility in a task that required transporting a small ball to a defined location to gain a reward. Bees were pretrained to know the correct location of the ball. Subsequently, to obtain a reward, bees had to move a displaced ball to the defined location. Bees that observed demonstration of the technique from a live or model demonstrator learned the task more efficiently than did bees observing a “ghost” demonstration (ball moved via magnet) or without demonstration. Instead of copying demonstrators moving balls over long distances, observers solved the task more efficiently, using the ball positioned closest to the target, even if it was of a different color than the one previously observed. Such unprecedented cognitive flexibility hints that entirely novel behaviors could emerge relatively swiftly in species whose lifestyle demands advanced learning abilities, should relevant ecological pressures arise.
- Loukola, O., Perry, C., Coscos, L., & Chittka, L. (2017). Bumblebees show cognitive flexibility by improving on an observed complex behavior Science, 355 (6327), 833-836 DOI: 10.1126/science.aag2360