![]() ![]() In North America, a population of about 15,000 birds has become established around St. This sparrow has occurred as a natural vagrant to Gibraltar, Tunisia, Algeria, Egypt Israel and Dubai. It was introduced successfully to Sardinia, eastern Indonesia, the Philippines and Micronesia, but introductions to New Zealand and Bermuda did not take root. The Eurasian Tree Sparrow has been introduced outside its native range, but has not always become established, possibly due to competition with the House Sparrow. dilutus'' reaches coastal Pakistan in winter and thousands of birds of this race move through eastern China in autumn. It is sedentary over most of its extensive range, but northernmost breeding populations migrate south for the winter, and small numbers leave southern Europe for North Africa and the Middle East. In South Asia it is found mainly in the temperate zone. It formerly bred in the Faroes, Malta and Gozo. The Eurasian Tree Sparrow's natural breeding range comprises most of temperate Europe and Asia south of about latitude 68°N and through Southeast Asia to Java and Bali. This may have resulted from the small size of the founding North American population and a consequent loss of genetic diversity. A study comparing the vocalisations of the introduced Missouri population with those of birds from Germany showed that the US birds had fewer shared syllable types and more structure within the population than the European sparrows. Other monosyllabic chirps are used in social contacts, and the flight call is a harsh ''teck''. #EURASIAN TREE SPARROW SERIES#The Eurasian Tree Sparrow has no true song, but its vocalisations include an excited series of ''tschip'' calls given by unpaired or courting males. The change in mass is due to an increase in blood volume to support active feather growth, and a generally higher water content in the body. Adult and juvenile Eurasian Tree Sparrows undergo a slow complete moult in the autumn, and show an increase in body mass despite a reduction in stored fat. Its contrasting face pattern makes this species easily identifiable in all plumages the smaller size and brown, not grey, crown are additional differences from the male House Sparrow. This sparrow is distinctive even within its genus in that it has no plumage differences between the sexes the juvenile also resembles the adult, although the colours tend to be duller. The legs are pale brown, and the bill is lead-blue in summer, becoming almost black in winter. The upperparts are light brown, streaked with black, and the brown wings have two distinct narrow white bars. #EURASIAN TREE SPARROW PATCH#The adult's crown and nape are rich chestnut, and there is a kidney-shaped black ear patch on each pure white cheek the chin, throat, and the area between the bill and throat are black. In eastern Asia and western Australia, this species is sometimes viewed as a pest, although it is also widely celebrated in oriental art.The Eurasian Tree Sparrow is 12.5–14 cm long, with a wingspan of about 21 cm and a weight of 24 g, making it roughly 10% smaller than the House Sparrow. The Eurasian tree sparrow's extensive range and large population ensure that it is not endangered globally, but there have been large declines in western European populations, in part due to changes in farming practices involving increased use of herbicides and loss of winter stubble fields. The Eurasian tree sparrow is widespread in the towns and cities of eastern Asia, but in Europe it is a bird of lightly wooded open countryside, with the house sparrow breeding in the more urban areas. As with other small birds, infection by parasites and diseases, and predation by birds of prey take their toll, and the typical life span is about two years. This sparrow feeds mainly on seeds, but invertebrates are also consumed, particularly during the breeding season. The typical clutch is five or six eggs which hatch in under two weeks. The Eurasian tree sparrow's untidy nest is built in a natural cavity, a hole in a building or the disused nest of a European magpie or white stork. Although several subspecies are recognised, the appearance of this bird varies little across its extensive range. This sparrow breeds over most of temperate Eurasia and Southeast Asia, where it is known as the tree sparrow, and it has been introduced elsewhere including the United States, where it is known as the Eurasian tree sparrow or German sparrow to differentiate it from the native unrelated American tree sparrow. The sexes are similarly plumaged, and young birds are a duller version of the adult. The Eurasian tree sparrow is a passerine bird in the sparrow family with a rich chestnut crown and nape, and a black patch on each pure white cheek. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |