| environ. | animal displacement The habit of many animal species of moving inside their habitats or of travelling, during migrations, to different biotopes, often considerable distances apart; in aquatic environments displacements can occur horizontally or vertically while in terrestrial environments animal populations that breed in the alpine or subalpine zones in summer, move to lower levels in winter; animal displacements usually follow circadian rhythms and are related to the necessity of finding breeding, resting and feeding areas | نزوح الحيوانات |