VENTRILOQUIAL AND IMITATIVE POWER OF BIRDS. 73 
in every song interjected the long plaintive call of the 
wood-pewee. The effect was unique and surprising. 
To those interested in the psychical or reason devel- 
opment of birds, this subject possesses increased interest. 
It is quite generally conceded that birds are not only 
the most interesting, but in some respects the most 
highly organized, especially in form, color, voice, and 
power of locomotion, of any of the so-called lower 
animals. In some directions, too, they are the most 
intelligent. Not only does their heredity count for 
much, but their experience is a large factor in shaping 
and modifying their manner of life. Many of them 
are quick to take advantage of any extraneous circum- 
stances by which their conditions may be bettered. 
How many cases come under our notice in which cause 
and effect plainly enter into their calculation. Several 
species throw out sentinels to guard against surprise, 
and these have signal notes well understood by all. 
They learn to avoid localities that are extra dangerous, 
and often gather in large numbers where safety is 
assured. They profit both by experience and example, 
often modifying their nesting habits, and adopting new 
methods for protection. What subterfuges our native 
birds make use of to mislead and baffle larger birds of 
prey. On the contrary, the English sparrows, mostly 
denizens of villages and cities, and not often having 
been exposed to the dangers that beset the birds of 
forests and fields, fall an easy prey to the smaller hawks, 
owls and shrikes that occasionally find their way among 
them. They know well enough how to avoid the 
