BIRDS 263 



very hard winters some migrate to northern Africa and the Canaries. They are 

 found all over Europe up to the Arctic Circle, and in Asia as far east a.s the 

 valley of the Yenesei. The jackdaw feeds on worms, insects, and the parasites 

 infesting domesticated animals, being often seen on the backs of sheep hunting 

 for ticks; and it will occasionally follow the plough, seeking its food in the 

 freshly turned furrows. 



The black redstart (Ruticilla titys) is another bird frequenting 

 ' buildings, probably on account of the rocky nature of its original 

 home. It is met with in mountainous districts higher than the tree-limit, and also 

 lower down in the forests and especially on high buildings in towns and villages. 

 From its home in the mountains, it seems to have followed the habitations of man 

 until it became distributed over the lowlands. In Ireland the black redstart was 

 first noticed in 1818, and about ten years later in England, whence it has spread 

 as a winter-visitor to Scotland. For some years it has been known as a straggler 

 to the Faeroes and Iceland, southern Sweden, and Denmark. It is common in 

 central and southern Europe, and Asia Minor, but is not found east of the Urals. 

 In winter it migrates to the mountains of northern Africa, and down the valley of 

 the Nile to Nubia. Partly a resident bird, at least in the south of the Continent, 

 it leaves central Europe at the end of October, or a little later, and returns in 

 March, when it is soon noticed by its peculiar song, often heard at night, which 

 consists of three or four bars, varied by a few croaks, and has little resemblance 

 to that of the common redstart, though the calls of both birds are alike, and the 

 young of both scream in the same way. The nest of the black redstart is rather 

 laro-e for the size of the bird, and is built in clefts and in holes in rocks and walls, 

 under the eaves of buildings, and in sheds and outhouses. It contains, in the 

 middle of April, sis or seven white eggs, and in June four or five ; within thirteen 

 days the young are hatched, which leave their birth-place when scarcely fledged. 

 The black redstart feeds on flying insects, caterpillars, and the small crustaceans 

 it finds on heaps of seaweed when in the neighbourhood of the coast. In habits 

 it is not unlike the redbreast, and its flight is quicker and easier than that of the 

 common redstart. 



By far the commonest bird among human habitations is the 

 ' house-sparrow (Passer dornesticus), which seems to have settled in 

 towns for the sake of the corn and seeds it finds in the streets, when it can 

 get none in the fields — a view supported by the fact that a great migration of 

 sparrows takes place from the towns to the country as soon as the crops begin to 

 ripen. The house-sparrow is found wherever grain grows, and its distribution 

 widens as the land is brought under cultivation. It followed agriculture across 

 Russia; and in Siberia, where it was unknown until the introduction of corn 

 cultivation in the eighteenth century, it has advanced as far east as Irkutsk. Like 

 all the finches, it feeds principally on seeds, and no bird known does so much to 

 limit the yield from farms and gardens. In southern Europe there exist several 

 races of sparrows, varying more or less from the one found in central Europe, but 

 the small differences in bodily proportions or even habits, are mostly confined to 



