408 BRITISH BIRDS. 
4 
sides, and in “fresh” weather filling the interior with a noise like thunder. 
Far in these gloomy caves, hidden away from enemies, even where the light 
of day cannot penetrate, the gentle Dove rears its young in peace. It 
seems not to mind the angry strife of waters, and the booming of the bil- 
lows never frightens it from its charge. The birds build their scanty nests 
on the ledges, sometimes far up in the inaccessible roof of the cavern, and 
very rarely within reach of the hand without climbing. The moment a 
boat approaches, the birds begin to leave their dark retreat, and before it 
has time to reach the land they dash out in twos and threes. The Rock- 
Dove makes a very slight nest of dry grass or seaweed, a dead stick or two, 
sometimes branches of heather, and Saxby states that green grass 1s occa- 
sionally used. The nest is very flat, and little or no skill is displayed in 
its construction. Sometimes one or two nests are built quite close to- 
gether; and as the bird’s breeding-season is so irregular, the same cave will 
often contain fresh eggs, eggs partly incubated, and young birds in all 
stages of growth. The eggs of the Rock-Dove are only two in number, 
pure white in colour, oval and rather elongated in form; they vary from 
1-5 to 1°38 inch in length, and from 1:2 to 1:1 inch in breadth. As a 
rule, the eggs of this bird are rather more rotund than those of the Ring- 
Dove, and they are always smaller than normal eggs of that bird. Both 
birds assist in incubating them; but the female performs the greater 
share of the task, and she is assiduously fed and tended by her mate. The 
young are reared in a similar manner to those of the Ring-Dove, and do 
not generally quit the nest until well able to fly. The breeding-season of 
the Rock-Dove is sometimes prolonged into the autumn; for Saxby has 
seen fresh eggs on the 11th of October, and it occasionally begins very 
early, as he once saw in the ovary “an egg, which would certainly have 
been perfect in a couple of days,” on the 21st of January. 
In hard weather the Rock-Dove may be seen on the beach searching for 
the seeds of various plants growing above high-water mark; but at that 
season it prefers to frequent the stubbles, if free from snow, and often con- 
gregates with Thrushes and Finches on the weedy pastures. It is also 
very fond of associating with tame Pigeons—with its kindred in fact ; for 
there is no doubt that it is from the present species or its close allies that 
all the varieties of domestic Pigeons have sprung. 
There is no evidence to show that the Rock-Dove is a migratory bird ; 
but in winter it will sometimes wander far from its accustomed haunts, 
occasionally in enormous flocks. Hard weather sometimes causes it to 
leave a district almost entirely, as Dixon found to be the case in several 
parts of Skye. 
The Rock-Dove differs from both the Ring-Dove and the Stock-Dove in 
having no brown tinge on the back, wing-coverts, or innermost secondaries, 
which are a paler lavender than the head and upper tail-coverts ; it agrees 
oll 
