Leach's Storm Petrel
Wave runners
The wave runners ( Oceanodroma leucorhoa ) is one of the world's 13 species of the genus of the wave runners. Their name from the wave runner of the behavior, often to slip with hanging legs just above the water. They dip their feet into the water one.
At the western European coasts of the wave runner is a breeding and annual bird. On the coasts of Central Europe it is regularly observed, on the other hand he is on the Baltic Sea and inland a very rare exception Guest.
- 5.1 Notes and references
- 5.2 Literature
- 5.3 External links
Morphology and characteristics
The wave runner is slightly larger than the petrel with a body length of 18 to 21 cm. The weight is on average between 40 and 50 g The wingspan is 45 to 50 cm. Wave runners have a dark gray-brown plumage. The wing and tail feathers are slightly darker. The rump is white with a dark center line. The feet are black. The wings are long, pointed, angled and bent in flight. The lower wing is slightly darker than the upper wing surface. Wave runners differ from petrels mainly by the forked tail. They also have, in contrast to petrel a bright band on the upper wing surface. The wing beats are rapid seeschwalbenähnlich. The flight is characterized by irregular body twists and frequent changes in flight altitude and speed. In contrast to the petrel they do not follow any ships.
Dissemination
Wave runners have a large distribution area. It extends across the whole of the North Atlantic, western Pacific and in the eastern Pacific from the Aleutian Islands to Baja California after. The European breeding colonies are located on a small island in northwestern Europe, such as the Lofoten Islands, Faroe Islands, Iceland, Ireland and the west coasts of Britain. The western Atlantic breeding colonies extending from Labrador to Maine and Massachusetts. The European breeding populations leave from September to November the breeding area and pull south of the equator before the coasts of Namibia and South Africa. Between April and May, they return to their breeding areas. In Germany you can see the rare birds on the North Sea, very rarely observed on the Baltic Sea.
Way of life
Wave runners spend most of their lives on the high seas. Like many other sea birds they only come ashore to breed.
Reproduction
The nesting occurs from April to June, mostly in burrows in coastal rocky plateaus or in hollows of rocks. The burrows dug by males with their feet. The beak is thereby used for loosening the soil. The diameter of the input cavity is about 6 to 7 cm, the length is about 50 cm. At the end of the cave is padded with the plant material Nistkammer, which has a diameter of about 16 cm.
In the Nistkammer is a single white, down slightly reddish brown spotted egg at the thicker end. Incubation period is 41 days on average. The birds take turns during incubation. With 63 to 70 days the young are capable of flight. During the breeding season the otherwise silent birds with rattling cooing sounds to communicate.
Food
The food is made on the sea -occurring large plankton, crustaceans, small fish, squid, jellyfish and Tran. The birds peck at prey in flight from the sea surface. The foraging primarily takes place during the day.
Enemies
Among the enemies of the wave runners are especially birds of prey, skuas and owls. To protect the nest before skuas return the animals in the breeding season only return at night to their burrows.
Life expectancy
The life expectancy of the animals in the wild is 20-24 years.
Stock
The global population is estimated at about 8 million individuals (M. Crosby in litt.2003 ). The largest part of the global breeding stock is more than 3 million breeding pairs on the uninhabited Canadian Baccalieu Iceland. The largest European populations are located on Iceland ( 80000-150000 pairs) and on the coasts of Great Britain ( 36400-64900 pairs) The holdings of the wave runners are not endangered and are assessed in the IUCN Red List with a status of "Least Concerned ".