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A peculiar bird, half raptorial, half web-footed, also inhabits 
the mountain plateaux, especially where they alternate with 
marshes, and draws attention to itself by its odd habits. This 
is the Buffon’s Skua (Stercorarius parasiticus), which unlike its 
relative in the belt of islands girding the coast, only makes its 
appearance in a single plumage with’ white abdomen, a black- 
bellied phase being unknown. With a curious cry it approaches 
the hunter, flaps about him in large circles, now and again 
remains motionless in the air, exactly like a Kestrel, and at last 
settles down upon a tussock to wait until the danger has passed 
away. Its food is as varied as that of its relative, and especially 
in the years in which the Lemmings undertake their mass 
wanderings, it lives largely upon them and various species of 
Arvicola, whilst it ordinarily persecutes young birds, and in times 
of scarcity contents itself with berries and insects. 
Though animal life under ordinary circumstances seems to be 
sparse upon these extensive wastes, it is otherwise in the years 
in which, as above mentioned, the Lemming (Myodes lemmus) 
multiplies beyond its normal number, and undertakes its emigra- 
tions. This renowned little rodent, with its handsome yellow 
and black pied skin and its hasty temper, lives as a rule a 
little-noticed life among the tussocks and the willow-scrub upon 
the high mountains, and as an essentially nocturnal animal one 
sees under ordinary circumstances little or nothing of it. 
But in certain years, under conditions which are inexplicable 
to us, there comes to pass their multiplication in an inordinate 
degree, for their prolificness during these years is almost 
incredible. Litter follows litter the whole summer through ; 
young ones, which first saw the light in the spring, are already 
breeding in the autumn, and the old individuals often produce a 
new litter of young inthe same nest, which the half-grown young 
of the preceding litter have not yet left. Gradually, as they 
over-run their native place, they set out upon their wanderings 
over the sides of the mountain; and in these great ‘*‘ Lemming- 
years”’ they are therefore common everywhere, alike upon the 
mountains and in the valleys, and by degrees reach far down 
upon the lowlands, where they are otherwise entirely unknown. 
They are now in motion at all hours of the day, they cross rivers 
