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World Migratory Bird Day – Why raise awareness of migrating birds?

SEF prides itself in finding sustainable development solutions for their clients. For example, our in-house Avifaunal Specialist, Robyn Phillips, is committed to assisting clients in helping conserve habitat for migratory birds and at the same time finding ways for the client to benefit from the presence of these bird species on their land.

World Migratory Bird Day is celebrated in the second weekend of May each year. It is an awareness-raising campaign highlighting the need for the protection of migratory birds and their habitats and is focussed on the Eurasian and African flyways. World Migratory Bird Day is an offshoot of International Migratory Bird Day which is the annual campaign focussing on the Americas.

Birds migrate in order to find the best ecological conditions and habitats for feeding, breeding and raising their young. When the conditions at breeding sites become unfavourable, due to changes in season, migratory birds fly to regions where conditions are more favourable, some flying over distances of hundreds and thousands of kilometres.

Many different migration patterns occur throughout the world. While the majority of birds migrate from northern summer breeding areas to wintering grounds in the south, some birds breed in southern Africa and migrate to northern wintering grounds. Others may migrate horizontally, to enjoy milder coastal climates in winter or by altitude, moving higher up a mountain in summer, and inhabiting lower lying areas during the winter months.

Of the approximately 1 800 bird species found in sub-Saharan Africa, nearly 200 species migrate seasonally between Eurasia and sub-Saharan Africa. A further 50 or so migrate between Africa and the Americas, Antarctica and oceanic islands. In addition, more than 580 species are known to undertake seasonal migrations within the continent.

Migratory birds have the perfect morphology and physiology that enables them to fly fast and across long distances. However, their journey is often an exhausting one during which they are pushed to their limits. For example the Red Knot (Calidris canutus) is a wader weighing around 220 g which breeds in the high Arctic tundra and overwinters on the west coast of Africa including South Africa. During its migration it loses nearly half of its body weight with birds weighing around 130 g when arriving in South Africa. Migratory birds therefore rarely fly non-stop to their destination but stop off during their journey frequently to rest and feed, or to sit out a spell of bad weather.

Migration is a perilous journey which exposes the birds to a wide range of threats, from natural predation and adverse weather, to manmade threats such as windfarms, powerlines, exposure to poisons and pesticides, and habitat destruction. Loss of habitat due to pollution, degradation or destruction for development, agriculture, grazing or mining, is the main threat facing migrating birds, as they depend on finding suitable breeding and wintering grounds as well as stopover sites along their flyways where they can rest and feed. The loss of any of these sites used by the birds during their annual cycle could have a dramatic impact on their survival.

The human use of land has a direct impact on migratory bird populations, which are particularly sensitive to any interference to the sites they use throughout their migratory cycle. Many aspects of human land use are extremely damaging to the birds’ habitats. For example, urbanisation and intensive agriculture can fragment and replace complex networks of habitats needed by the birds. Deforestation, afforestation and mineral extraction can damage entire regions along the birds’ annual migration paths. Land reclamation and biofuel production remove or degrade important wetlands and other habitats for many migratory bird species. In addition, man-made obstacles such as rotating wind turbines, powerlines, tall buildings and reflecting glass windows, pose a threat to migratory birds by causing barriers to migration.

These are only a few examples and often a substantial decrease in population numbers within a species is the result of a combination of such factors. While human survival depends on transformations of natural areas, a sustainable use of land is vital to reduce the impacts on our natural resources, such as water, soil, nutrients, plants and animals.

Attention must be given to the careful future planning of human land use which must be guided by strategic conservation planning. It is imperative to gain an understanding of migratory flyways and how migratory bird populations are sensitive to land use changes. Even in an urban or industrial landscape, patches of natural habitat, especially wetland areas can provide vital stop-over refuges for migratory birds. Careful consideration must be given to all sites when considering the impacts of development and solutions can be achieved through practical mitigation that will benefit both human expansion and conservation of our natural resources.

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