Western Jackdaw - Distribution and Habitat

Distribution and Habitat

The Western Jackdaw is found from north-west Africa through all of Europe, except for the extreme north, and eastwards through central Asia to the eastern Himalayas and Lake Baikal. To the east, it occurs throughout Turkey, the Caucasus, Iran, Iraq, Afghanistan, Pakistan, and north-west India. However, it is regionally extinct in Malta and Tunisia. The range is vast, with an estimated global extent of between 1 million and 10 million square kilometres (4 hundred thousand to 4 million square miles). It has a large global population, with an estimated 15.6 to 45 million individuals in Europe alone. Censuses of bird populations in marginal uplands in Britain show that Western Jackdaws greatly increased in numbers between the 1970s and 2010, although this increase may be related to recovery from previous periods when they were regarded as pests. The UK population was estimated at 2.5 million individuals in 1998, up from 780,000 in 1970.

Most populations are resident, but the northern and eastern populations are more migratory, relocating to wintering areas between September and November and returning between February and early May. Their range expands northwards into Russia to Siberia during summer, and retracts in winter. They are vagrants to the Faroe Islands, particularly in the winter and spring, and occasionally to Iceland. Elsewhere, Western Jackdaws congregate over winter in the Ural Valley in north-western Kazakhstan, the north Caspian, and the Tian Shan region of western China. They are winter visitors to the Quetta Valley in western Pakistan, and are winter vagrants to Lebanon, where they were first recorded in 1962. In Syria, they are winter vagrants and rare residents with some confirmed breeding taking place. The soemmerringii subspecies occurs in south-central Siberia and extreme north-west China and is accidental to Hokkaido, Japan. A small number of Western Jackdaws reached the north-east of North America in the 1980s and have been found from Atlantic Canada to Pennsylvania. They have also occurred as vagrants in Gibraltar, Mauritania, and Saint Pierre and Miquelon, and one is reported to have been seen in Egypt.

Western Jackdaws inhabit wooded steppes, pastures, cultivated land, coastal cliffs, and towns. They thrive when forested areas are cleared and converted to fields and open areas. Habitats with a mix of large trees, buildings, and open ground are preferred; open fields are left to the Rook, and more wooded areas to the Eurasian Jay (Garrulus glandarius). Along with other corvids such as the Rook, Common Raven (Corvus corax), and Hooded Crow (C. cornix), some Western Jackdaws spend the winter in urban parks; populations measured in three urban parks in Warsaw show increases from October to December, possibly due to Western Jackdaws migrating there from areas further north. The same data from Warsaw, collected from 1977 to 2003, showed that the wintering Western Jackdaw population had increased four-fold. The cause of the increase is unknown, but a reduction in the number of Rooks may have benefited the species locally, or Rooks overwintering in Belarus may have caused Western Jackdaws to relocate to Warsaw.