412 BRITISH BIRDS. 
known as passing through on migration; but a considerable number 
remain to breed, especially in Algeria. It is extremely common in summer 
in the Canaries, but is only occasionally found in Madeira. The winter- 
quarters of the Turtle-Dove are absolutely unknown; but as it passes 
through North Africa, and has not been found in South Africa, they must 
be in some unknown region in the centre of that continent. 
A desert form of the Turtle-Dove, Turtur isabellinus, is a summer visitor 
to North-east Africa, and differs from our bird in having the wings only 
six instead of seven inches long, and the head buffish brown instead of 
bluish grey. In South-west Siberia the Turtle-Dove is replaced by a very 
nearly allied species, 7. ferrago, which occurs together with our bird in 
Turkestan, and with another allied species, 7. orientalis, in India, the 
latter being its representative in South-east Siberia, China, and Japan. 
T. ferrago differs from our bird in being larger, in having the tips of the 
feathers on the sides of the neck slaty blue imstead of nearly white, 
and the colour of the breast much less vinaceous. In 7. orientalis the 
colour of the breast more closely resembles that of our bird, but the under 
tail-coverts and the pale tips of the tail-feathers are pale slate-grey instead 
of white. The East-Siberian bird appears to be only subspecifically distinct 
from the West-Siberian bird, as intermediate forms occur in India, where 
the range of these two forms overlap. In Turkestan, where the range of 
the West-Siberian bird overlaps that of the European bird, it is not known 
that any intermediate forms occur between them. 
The Turtle-Dove is one of the latest summer visitors to this country, 
sometimes arriving during the last days of April, but more frequently not 
until the first week of May. At Gibraltar its migration lasts from the 
middle of April to the middle of May, the great body crossing the Straits 
during the first week of the latter month. In Greece and Asia Minor the 
period of the spring migration is the same. Its departure from the British 
_ Islands usually takes place in September ; but individuals are occasionally 
met with much later. 7 
The Turtle-Dove is very careful to conceal its nest, and breeds only 
in districts that afford it plenty of cover. It is very partial to dense 
game-coverts and plantations, and loves the more open districts if the 
hedges are tall and thick. It also frequents parks and pleasure-grounds, 
and is commonly met with in close shrubberies. Soon after their arrival 
the woods and groves are full of their soft note, which is a rich low 
coor-r-r-coor-r-r, prolonged for some time and often modulated in different 
ways. In cultivated districts it is a very timid bird, and at the least 
alarm seeks safety amongst the trees, where, when perched, it is ever 
looking anxiously from side to side as if fearful of an enemy’s approach ; 
but it is a very easy bird to shoot when feeding in open country where it 
is not molested. 
