I used to hang out with behavioral psychology grad students (BF Skinner types) who did a lot of research with pigeons. They transported the birds head-down in juice pitchers with air holes punched at the bottom; they just held the pitcher up to the cage and the bird would jump into it, sometimes so hard they would knock themselves out. They loved that lever-pressing shit - it helped that they were kept at 80% of their normal food intake to maximize the reinforcing effect of the pellets.
I used to hang out with behavioral psychology grad students (BF Skinner types) who did a lot of research with pigeons. They transported the birds head-down in juice pitchers with air holes punched at the bottom; they just held the pitcher up to the cage and the bird would jump into it, sometimes so hard they would knock themselves out. They loved that lever-pressing shit - it helped that they were kept at 80% of their normal food intake to maximize the reinforcing effect of the pellets.
So they were starving the birds? Kinda messed up.