ARCTIC BLUE-THROATED ROBIN. 273 
Lapland and the tundras of Siberia are not level. The peat is imper- 
vious to water; and there is a constant struggle going on between the 
rich and rank vegetation which establishes itself there and the water 
which lies on the flat places and is always running down the slopes when 
the snow melts. The tundra is seldom smooth like a common, but is 
_ generally a cluster of little hammocks or mounds covered over with rushes 
earices, cloudberry, and other ground fruits, with sometimes a stunted 
birch or willow scarcely higher than the coarse grass. These hummocks 
are the favourite breeding-places of the Arctic Bluethroat. I have 
generally found the nest well concealed in a snug hole on the side of one 
of these hummocks, just such a place as a Robin would choose in such 
a locality. 
The nest is not unlike that of a Robin. The hole is well filled with 
dry grass and roots, and at the far end a neat deep cup is formed lined 
with fine roots and hair. It is almost impossible to find the nest, except 
by accidentally frightening off the bird, and even then it often takes some 
time, so carefully is it concealed. The eggs are from five to six in 
number, and are laid about the middle of June. They are greenish blue, 
more or less distinctly marbled with pale reddish brown, and are very 
similar to the eggs of the Nightingale. They may be described as 
miniature eggs of the Redwing. They measure from ‘8 to ‘69 inch 
in length, and from °56 to ‘53 inch in breadth. 
The food of the Arctic Bluethroat is partly vegetable and partly 
animal. A lover of low and swampy districts—marshy grounds studded 
with willow clumps, and wet meadows, it obtains earth-worms in 
abundance, also various kinds of insects and their larve, its principal 
food during the breeding-season being undoubtedly mosquitoes. It also 
eats small seeds of various kinds. Like the Robin, the Redstart, and 
other nearly allied birds, the Arctic Bluethroat obtains much of its 
insect food when hovering in the air in a similar manner to the Fly- 
catchers; and when searching amongst withered leaves or moss upon 
the ground, its actions are almost precisely the same as those of the 
Robin or the Hedge-Accentor. 
The Arctic Bluethroat has the whole of the upper parts uniform brown, 
except a white or pale buff streak over the eye from the base of the bill 
backwards, and the tail, which is blackish brown with the basal half bright 
chestnut, except the two centre feathers, which are uniform brown. The 
chin, cheeks, throat, and upper breast are metallic cobalt-blue, with a large 
chestnut spot in the centre of the lower throat ; below the blue is a band of 
black, and below that the chestnut reappears in a broad band across the 
lower breast, the rest of the underparts being buffish white. Bill black ; 
legs, feet, claws, and irides dark brown. The female is not so showy as 
the male, simply having a dark-brown band across the chest; but some- 
VOL, I. T 
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