THE STORMY PETREL. 
869 
rather birds of the twilight, than diurnal. When the 
ocean is calm they generally approach the ship, about 
sundown, in small parties of four or five, ten or fifteen, 
and often even in large flocks of more than fifty at a time. 
They assemble in the wake of the vessel, turning against 
the wind, and gliding without a heat of their pinions 
close over the surface of the waves, always keeping at the 
same height from the water, cleverly rising and falling 
in unison with its every motion. Sometimes they 
literally run, after a singular fashion, over the surface of 
the billows, aided by the points of their wings, but never 
for more than a short distance at a time : this is effected 
by just touching the surface continually with their tiny 
feet and springing from it again; it looks as though 
they were dancing over the crests of the waves. This 
dainty child of the sea will rest for a moment, apparently 
motionless, on any floating substance able to support its - 
weight, by pattering lightly with its feet, half supported, 
by the action of the wind, on its raised pinions: at the 
same time they always keep their eye on the water, and 
are constantly engaged in picking up something from its 
surface. When dark clouds cover the heavens, and cast 
a mid-day twilight o’er the ocean, these birds are always 
more lively than on a calm, still day; and when the 
storm rages, black as night, and lashes the angry billows 
into foam, then only do the Stormy Petrels really seem to 
arouse themselves, and their apparently gleeful call, “ vibb, 
vibb, ouay, ouay,” is blended with the howling of the 
wind and roar of the sea. Their flight now becomes 
changed in its character: they dart like arrows far away 
over the ocean, describing bold circles, active curves, 
and turns of every description, moving their wings with 
intense force and rapidity; they hold their own with their 
