An Outlook on Migration of Birds and types of Geographical Migratory Patterns

Abstract

Migration is a normal phenomenon in almost all organisms but most communal seasonal phenomenon in birds to find suitable habitats for feeding, breeding and raising their young ones. It allows birds to explore themselves in search of food and to settle in areas where they could otherwise not live. Migratory behaviour has been intensely studied for over a century but there is still mystery in migration of birds that how it originated and how it evolved. Especially the use and evolution of migration routes seems to be a neglected element. Seasonal changes and food supplies are the basic consequence of the evaluation of migratory behaviours. It is still point of discussion, if migratory behaviours have evolved as consequence of not only food but also by competition. Migratory routes probably have come forth out directional preferences which have become fixed by natural selection. Some birds move between their breeding and wintering grounds in a straight line, basically, large crossings are seen from America to Asia. Migratory journeys also occur largely independent of geomorphological and landscape features i.e. broad-front migration. Multiple migratory routes are used by many species in Africa, there is no real preferred migratory route among species. Instead it is believed here that the use of different routes is related to different populations of one species with different breeding grounds, consequently using other routes may cause more distance to travel. The present review work is dealt with different reasons of migration of birds along with types of geographical migratory pattern in birds on the basis of past reviews which already done by the different researchers. Furthermore, much study is needed to reveal many facts regarding bird’s migration.