waves. And this, apparently, to escape, so far as is possible, 
the force of the wind. Larks, starlings, thrushes, and other 
small birds, can sometimes be seen during daylight crossing the 
North Sea in their thousands. At such times many will often 
afford themselves a brief rest in the rigging of ships, homeward 
bound, but the main host hurry on. The beautiful golden 
crested wren, our smallest British migrant, is one of these. A 
glance at our charming coloured plate will show at once that 
the wing is not that of a bird of strong flight. There is no more 
interesting experience to the bird-lover than that of watching the 
tired travellers drop earthwards, as they leave the dreadful sea 
behind them. 
With all birds yet retaining the power of flight there is 
always a liberal “‘ margin of safety ” in regard to the wing area. 
That is to say this is always in excess of the minimum area 
necessary to make flight possible. This much, indeed, is manifest 
from the fact that the eagle can bear off a victim equalling him- 
self in weight. Should he miscalculate, he can always drop his 
burden, or lessen its weight by eating part of it on the spot. Not 
so the osprey, or the sea-eagle, which have been known to plunge 
down and drive their talons into fishes too large to be raised. 
Unable to release their grip, death, by drowning, has inevitably 
followed. 
Sometimes the burden is a passenger, instead of a victim. 
45. 
