Beaks and Bills at 
All this is expressive rather of the mental than the phys- 
ical life of the bird. 
Within a period of five minutes I have observed the 
following uses of the beak of a parrot perching in my 
study. With its mandibles it picked up a sunflower 
seed and comminuted it; it then hooked the upper man- 
dible into a wire and swung itself along; gnawed at a nest- 
ing-hole it had begun to excavate; nibbled gently at 
my finger, showing affection; bit fiercely in anger and 
fear at a dead snake which I presented; preened several 
feathers of one wing, smoothing out all the dislodged 
barbs; rattled its beak along the wires to make a sound 
to attract my attention; and finally seized its water-pan 
and turned it over in pure playfulness! 
