RECENT EMIGRATION 171 



range in our area during the past hundred years. If the 

 early records of the distribution of the Missel Thrush in 

 the British Islands are reliable, we learn that this bird 

 towards the close of the last century was chiefly con- 

 fined to the lowlands and well-cultivated districts. 

 Whether it was entirely absent from Ireland we have 

 no means of accurately ascertaining, but the probability 

 is that the bird was thinly dispersed over that area as it 

 was in England. Emigration during the past hundred 

 years has been steadily in progress, and at the present 

 time this Thrush is generally distributed over our main- 

 land area. It has also extended its range to the 

 Hebrides, but not yet to the Orkneys. When in Skye 

 some years ago I was informed that the Missel Thrush 

 had become fairly numerous in the island until the 

 severe winter of 1879-80, which almost exterminated it. 

 It is now, however, so I am informed, slowly increasing 

 again in that area. The Song Thrush ( Turdus nuisiciis) 

 is also extending its range as it increases in numbers in 

 the northern portions of Scotland, and that this fact is 

 not due to the spread of cultivation and tree planting 

 seems proved by the fact of its present rarity in wooded 

 areas of long standing suitable to its requirements. 

 The Blackbird {Alenila ineriila) is, comparatively speak- 

 ing, rapidly extending its range northwards and west- 

 wards, and even in some districts encroaching upon the 

 area occupied by the Ring Ouzel, and compelling that 

 species to retire, as in Ross-shire. Macgillivray records 

 that in his day the Blackbird did not breed on the 

 Hebrides ; it is now known to nest on them as far- north 

 as Lewis. It has also reached the Orkneys, but only 

 visits the Shetlands as an abnormal migrant. The 



