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What are migratory birds?

Migration is a natural process, whereby different birds fly over distances of hundreds to thousands of kilometers in order to find the best ecological conditions and habitats for feeding, breeding and raising their young. For instance, when the conditions in the breeding grounds become very difficult due to low temperatures migratory birds would fly to a region where conditions are less rough. There are many different migration patterns. Most birds migrate from northern breeding areas in the summer, to southern wintering grounds. However, some birds breed in the far south of Africa, and migrate to northern wintering grounds, or horizontally, to enjoy the milder coastal climates in winter. Other birds migrate in terms of altitude, moving higher up a mountain in summer, and wintering on the lowlands.

Migratory birds have the perfect morphology and physiology to fly fast and over long distances. However, they often experience an exhausting journey during which they go to their limits. The Red Knot e.g., a 24 cm long wader with a weight of around 220 g, breeds in Siberia and overwinters on the African West coast, some of its species even going down to South Africa. During its migration it loses nearly half of its body weight. Migratory birds therefore rarely fly to their destination non-stop but break their journey frequently to rest and feed, or to sit out a spell of bad weather. How migrating birds exactly find their flyways is not fully understood. Newest experiments indicate that they are orientating along the magnetic earth field with special light receptors in their eyes.


The symbolic meaning of birds and their journeys

Illustration: Yves FagniartHumans have always been fascinated and inspired by the phenomenon of bird migration. In ancient Greece the bird of Athena represented the renewal of life. A dove, with an olive branch in its beak, returned to Noah's ark to announce the end of the deadly flood. The dove remained a symbol of peace and hope. For the Egypt of pharaohs the falcon had protective powers and was linked to royalty. For the Native Americans birds had different meanings, always positive and linked to the concepts of unity, freedom, community, safe return, love and celebration of life.

In dreams birds embody fantasy, ideas and cogitations. The image of a flying bird is immediately connected with lightness and freedom and the hence derived sentence “to be free as a bird”. Many people associate flocks of migrating birds in the typical V-like alignment with the change of season, but also with perfection, beauty and harmony. Until the 18th century people believed that swallows sink in mires at the beginning of autumn and appear again as amphibians in the following spring. And still today some parents mark their houses with painted storks to indicate that a new baby is born.

In almost all cultures, for centuries flocks of birds have announced the arrival of spring, and the yearly rebirth of nature associated with it. The social acceptance of birds as messengers of life was accompanied by the knowledge that migration had indeed an important role to play in ecosystem functioning, as providers of services and food supply.


Why migratory birds need to be protected

Photo: Helmut KruckenbergMany bird species need migration for their survival. However, migration is a perilous journey, presenting a wide range of threats. Only a small number of birds are actually threatened by natural events. Sad but true, human activities are the source for most dangers migrating birds are exposed to. And as diverse as people and their habits in different countries are, so are threats the birds face. The loss of habitat due to pollution or exploitation caused by encroachment for settlement, agriculture, grazing e.g. is the main threat to migrating birds, which are dependent on finding suitable breeding and wintering grounds as well as stopover sites along their flyways where they can rest and breed. The loss of any of these sites used by the birds during their annual cycle could have a dramatic impact on the birds’ survival chance. Also high-voltage power lines and wind turbines have a dramatic impact on birds, which are in danger of being killed by electrocution or collision. Poaching remains a widely diffused practice in countries where people are highly dependent on biodiversity for their livelihoods. These are only a few examples and often a clear decrease of population within a species is the result of a combination of such factors and therefore hard to identify.

At the same time, flying over long distances means crossing many international borders and entering different political areas with their own environmental politics, legislation and conservation measures. It is clear that international cooperation between governments, NGOs and other stakeholders is needed along the whole flyway of a species in order to share knowledge and to coordinate conservation efforts. Without cooperation all measures taken to tackle the threats for migratory birds in country A could be in vain if e.g. unsustainable taking is accepted in country B. The necessary legal framework and coordinative instruments for such international cooperation is provided by international agreements such as CMS and AEWA. It is hoped that the WMBD with its global outreach will be an effective tool for the international community to raise awareness on the threats for migrating birds and their ecological importance, especially among the general public.