Seabird

As seabirds or marine birds are called bird species, most of which are tied with their way of life on the sea. A total of 275 different species have to adapt to life on the sea. Typical seabirds, for example, Procellariiformes, which also includes the albatrosses, which are specially adapted to a permanent flying over the sea. They use the thermals above the waves, which give them buoyancy over time. Other examples of seabirds are penguins, auks such as puffins or guillemot, oystercatchers and avocets.

General features

Although seabirds often show very large differences in their lifestyle, their behavior and physiology, also striking features of a convergent evolution are simultaneously determined. The particular circumstances of their environment and the use of specific food niches have led regulatory and family across to similar adjustments with them. Thus, for example, the Velvet Scoter on large nostrils, through which it excretes the salt from the seawater swallowed by it. This feature is not very common to find within the Anatidae, but is for example typical of Procellariiformes. Seabirds have not as colorful feathers like other birds in general. Their plumage is often inconspicuous black, white or gray to brown.

Seabirds live longer, begin their reproduction at a later age and have fewer young than other birds. Typically, they invest in their offspring but also more time than is usual in other birds. Most seabirds nest in colonies, the number of breeding pairs may vary from a few dozen up to several million. Some species of them are known for their long annual train in which they cross the equator and sometimes fly around the world.

Types of adaptation

Basically, sea birds can be differentiated into two types of adaptation:

• Seabirds such as terns and petrels live in the airspace above the sea. They are consistently excellent sailors to their anatomical features include long, pointed wings and narrow, delicate legs.
• Seabirds such as alkene and penguins are mainly floating on the water surface sea birds. They move with the help of their short and stout legs and the wing continued under water. They are therefore also known as blades divers.

Threat and protection

Seabirds and humans have a long history together, as humans used the birds as hunting, fishing became aware of accumulating schools of fish through it and back by sailors found they way to the country.

While some species of gulls from industrial fishing and waste their benefit, the human impact on the seas was threatening acts by pollution and overfishing for most seabird species. It has been calculated that only discards the Lower Saxon shrimp fishery in 1993 were sufficient to feed about 60,000 birds a year. Some species, such as silver and black-headed gulls, discarding use particularly successful. In this respect, the discard is likely to lead to an unnatural increase in the population size of some species of gulls in the Wadden Sea and therefore to a shift in the natural species composition at the nesting shorebirds.

Families

Not all species of a family must be sea birds (eg ducks, long-tailed ducks and eiders, but not mallards ). Even if there is no scientifically defined boundary, birds following orders and families can be referred to as seabirds:

• Order Anseriformes ( Anseriformes ) Ducks ( Anatidae )

• Boobies ( Sulidae )
• Frigate ( Fregatidae )

• Albatrosses ( Diomedeidae )
• Petrels ( Hydrobatidae )
• Petrels ( Procellariidae )
• Diving petrels ( Pelecanoididae )

• Loons ( Gaviidae )

• Penguins ( Spheniscidae )

• Oystercatcher ( Haematopodida )
• Phalarope ( Phalaropus )
• Skuas ( Stercorariidae )
• Gulls ( Laridae )
• Terns ( Sternidae )
• Auks ( Alcidae )