The goal in the cylinder test is to see if the test subject will peck at the cylinder to try to get the reward placed in the middle or if they directly use a previously learned detour to retrieve the treat (figure a,b).

Before testing, the birds needed to go through two learning steps. Firstly I trained the birds on see through materials. I did this by placing a three walled Plexiglas square in the arena and presenting mealworms on various places so that the birds could see the worms through the Plexiglas but had to walk around to retrieve them (figure c,d). Once the birds had learned this they were moved on to the next learning step which was the opaque cylinder (figure e,f). The opaque cylinder was used to teach the birds the detour. That there is a treat in the middle of the cylinder and they can reach it by sticking their head in through one of the open sides. Once they had learned this detour they were tested with the transparent cylinder.