A significant increase in agonistic behavior occurred when the distribution of the food was restricted, but the amount of food remained normal. Highly significant increases in the frequency of ...

A tiger walks the same worn groove along the edge of its exhibit, like a broken record. A parrot methodically plucks out its own feathers until bare skin shows through. To a casual visitor, these can ...

In semi-natural mixed-sex groups, rabbits (Oryctolagus cuniculus) organize their social life by forming a hierarchy, which is characterized by linearity and stability. Compared to the natural ...