Vol. 10, Special Issue 4 (2021)

Author(s):
Deepika D Caesar, Aditya Mishra, Jyotsana shakkarpude, Anand K Jain, Sanju Mandal, Suman Sant, Manoj Kumar Ahirwar and Anil Kumar Singh

Abstract:
Migration has come from the latin word “migrare” may be defined as the seasonal movement of animals from one place to another. Bird migration was described by L. Thomson as “changes of habitat periodically recurring and alternating in direction, which tend to secure optimum environment conditions at all times”. Temperature, food supply, or the amount of daylight animals migrate, breeding is one of the purposes. Migratory birds undergo two migrations per year: a fall migration and a spring migration. Pre-migratory fattening is the behavior shown by the migratory birds in which they eat food in excess (hyperphagia) and gain weight quickly just to deal with the high energy demands for long migratory flight. This fueling is done before the migratory take off as well as at stopover sites of their routes. Fuel reserves reach maximum levels when birds start long non-stop flight. Feathers’ aerodynamic and insulatory functions are affected by long flight and its exposure to light therefore, the plumage is replaced periodically through a process known as molt.