Thick-billed Murre
Thick-billed murres
The thick-billed murre (Uria lomvia ) is a species of bird belonging to the order Charadriiformes and the family of the Auks. It occurs in many parts of northern Asia, North America and Europe. It is a great Auk, which is built a little stronger than the guillemot and a slightly larger head and thicker neck as this species has. On land, the thick-billed murre occupies either an upright posture or lying on his stomach.
There are recognized two extant subspecies, however, are hardly differentiated genetically.
- 2.1 Nutrition and behavior
- 2.2 Reproduction
- 6.1 Literature
- 6.2 External links
- 6.3 Single Documents
Features
The thick-billed murre is similar to the guillemot in appearance and in lifestyle. The former differs from the latter by the thicker beak with white stripes, the darker, black-brown top and the lack of gray penciling on the flanks. She is also on average slightly larger than the guillemot. The black -throated plumage extends to the anterior chest so that forms on the two front sides of the body, a white, inverted V. The bird has an elongated body, a short neck and a small head like all Auks. The wings are relatively small. The legs are long and have three short toes. They may be colored from light red over gray yellow to greenish yellow. The sharp beak tapers towards the end. It is provided and slate black with a white stripe on the upper mandible parallel to the mouth opening. The inside of the mouth and the tongue is yellow.
Dickschnabellummen swim very high on the water, the tail is not submerged when swimming. They fly only with great difficulty and never land on flat ground.
Coloring and dimensions
In the thick-billed murre breeding plumage has a black to black brown top. The head and neck are of a dark color. The tips of the secondaries are white, the primaries are dark brown. Behind the eye is a small featherless furrow. The bottom up to his chest as the under tail-coverts white.
The simplicity dress matches the splendor of dress, the neck and the head are, however, black and white colored. About the front neck pulls a white band, which widens to the throat center to the neck down. The lower half of the face and throat are completely white. However, the thick-billed murre shows the head more than the black guillemot.
It is 42 to 48 inches long, reaches a wingspan of 75 centimeters and is 750-1480 grams.
Flight image
The lower wing has two colors: the edges are translucent and dark brown, while the rest of the plumage of the underside is white. In flight, the thick-billed murre of the guillemot by the lack of black axillaries is to be distinguished. The bird flaps its wings quickly and is very agile despite its small wings in the air. The flight is straight and faintly reminiscent of that of a pigeon.
Way of life
Nutrition and Behavior
The thick-billed murre breeds in large colonies on rocky cliffs. There it occurs together with the Guillemots, but there are no pairs of both types - let alone hybrids of both species - before. The bird needs to fly much run on water (running flight ). Once in the air it can fly long distances without interruption.
It eats small fish in size 5-15 centimeters, crustaceans (mainly krill ), snails, mussels and squid. The Lumme immersed in groups of 20 to 200 birds from the water surface for food. She swallows its prey usually already under water.
Reproduction
The mating season of the thick-billed murre begins soon after arrival in the breeding areas, ie from March to April. The female lays an egg in May or June on a ledge. The almost pear- like shape protects it from rolling away. It is on the white to gray or turquoise ground spotted variable. The egg is incubated for 30 to 36 days. The young are fed with small fish which are brought by both partners in beak. After 18 to 25 days, they are lured down with shouts of parents the cliffs. They jump down and are slowed down by the wind something before they come to the surface. You can reach the ability to fly at the age of one and a half months. Back in July of exit begins in the wintering areas.
Habitat and Distribution
The thick-billed murre breeds on cliffs in northern Russia, northern Canada, Alaska, Greenland, Iceland, northern Norway, on the Russian islands, Spitsbergen, on the Sea of Okhotsk and Sakhalin and Hokkaido.
It is a migratory bird and can travel long distances without interruption. On the migration route it is because of their size rarely driven away, as is the case for example when auks. An exception is Mexico, southern Europe and the inner North America, such as the Great Lakes. The wintering areas of birds are located in northern and central Europe, Russia, Japan, on the west coast of the USA, on the Labrador Peninsula and on some Atlantic islands such as Newfoundland and the Faroe Islands.
The further north breeds a population, the more northerly wintering birds also. So hibernate estimates about 10,000 to 100,000 of the 350000-400000 copies Greenland to Iceland.
The intensive hunt for adult birds and the collection of eggs has greatly harmed its kind in Greenland and Newfoundland. In the Russian Barents Sea, hunting is now permitted only to the inhabitants of local polar stations. Thick-billed murres are very sensitive to pollution from oil or gas wells. Also, they often remain hanging and dying in fishing nets. For these reasons the species is listed in the IUCN Red List as Vulnerable.
Stock
The stock in the North Atlantic was the millennium approximately 6.5 million breeding pairs. The number of Pacific breeding pairs is estimated at 4.5 million.
Among the European regions with a large population of guillemots include Iceland with 341000-861000 breeding pairs, Svalbard, with 850,000 breeding pairs and Greenland with 350000-400000 breeding pairs. In the north of the European part of Russia brooding about 250,000 to 500,000 breeding pairs. In the north, Norway 's first successful broods for the year 1964 are occupied. Meanwhile there 1,000 to 2,000 breeding pairs are counted.
Subspecies
There are three subspecies recognized, of which one died.
- U. l lomvia (Linnaeus, 1758) - represents the nominate constitute - Canada, Russia, Northern Europe
- U. l arra ( Pallas, 1811) - Canada, Alaska, Russia, Japan
- † l U. affinis ( Marsh, 1870) - U.S. during the late Pleistocene, extinct; is considered by some authors as distinct species
Carl Linnaeus described the thick-billed murre 1758 Alca lomvia.
The following two earlier additionally defined subspecies are no longer recognized as a subspecies. The distinction based solely on minimum coloration differences.
- U. l heckeri Portenko, 1944 - Russia
- U. l eleonorae Portenko, 1937 - Russia