Song Birds and Water Fowl 
find a difference in instinct, that does not nec- 
essarily indicate a constitutional inferiority, as 
architects; but one that exactly conforms to 
the difference of circumstances; wherein mere 
safety, requisite durability, and convenience are 
just as much the determining thought as among 
the land birds. 
In the remote and desolate regions to which, 
for the most part, water fowl resort, they are 
largely, and often entirely, exempt from the 
depredations of various enemies that so con- 
stantly endanger the abodes of land birds; and 
they have little cause for anxiety and conceal- 
ment, when man and beast seldom invade their 
territory. Moreover, the unwooded sea-coast, 
to which so many of them resort, affords no 
opportunity for building above the ground; 
and either one or the other of these circum- 
stances affords sufficient reason for their com- 
monly nesting directly on the ground, with little 
or no pretence of secrecy ; sometimes, indeed, 
so openly and closely together, that the chance 
explorer is likely to step upon the eggs, as in 
the case of terns on the Atlantic coast, and of 
murres in Alaska. But no such elaborate con- 
struction as is required in trees is needed on 
solid ground, where the merest outline of a nest 
148 
