People's influence on migrating birds
A lack of sand-eels in Shetland has had a devastating effect on breeding Arctic Terns in the early 1990's. Of 4,000 pairs nesting there that year none produced any young because of a lack of food. It is believed that over-fishing by man is a major cause. If this situation continues, migrating to our shores will no longer benefit the Arctic Tern as a species - if they cannot breed there is no point in making the journey.
In the past, the stream of small birds migrating north each spring brought a welcome change of diet to impoverished and undernourished Mediterranean people. Today, they are no longer so poor, nor do they need to supplement their diet with small birds. But the custom of killing birds continues, both to sell for food and for 'sport'. Millions of song birds are trapped and shot each years by hunters in Malta, Italy, France and Spain (among others).
With numbers of birds declining because of environmental changes, we cannot afford to let this continue. BirdWatch Ireland supports a campaign to make sure European laws to ban bird killing are enforced.
Habitat loss - estuaries
Estuaries in Ireland are extremely important for wildfowl, such as the Brent Goose, and wading birds. They support large numbers of these birds in winter. Estuaries also provide essential feeding grounds for waders that need to refuel as they travel between their northern breeding grounds and wintering areas in southern Europe and West Africa.
But many of our important estuaries are threatened. Land claim, industrial development, pollution, disturbance from recreation and the possibility of tidal barrages all threaten these birds havens. All of these threats could mean fewer feeding areas available for birds at a stage in their journeys. If these estuaries disappear, fewer birds will survive the winter and their migration journeys.
A great natural barrier to migration is the Sahara desert. Many birds spend the winter in areas just beyond it. These birds suffer particularly when there is a drought in this region, the Sahel. A drought will kill all the vegetation and the insect life it supports.
The Whitethroat spends the winter in this region. Quite suddenly the numbers of Whitethroats reaching Britain and Ireland in spring dropped alarmingly. We eventually found the reason - its winter food supply had disappeared from the Sahel. The reason for the decline in the numbers of Sand Martins and other birds also has its roots here.
One of the reasons why droughts are becoming more common is the extensive over-grazing by cattle of the remaining grasslands south of the Sahara. As the area of the drought extends, there is less vegetation to feed the cattle. The traditional herding customs of the native tribes in this region are compounding the effects of the drought. Not only are the people threatening their own survival, they are upsetting the pattern of migration for the birds that also depend on these areas.
Please click on the "Next Page" link below to go to Part 2 of this section.