Their Curious Cries 329 
In captivity these birds are somewhat silent; after being fed 
they usually give a series of weird ‘“boo-oos” of satisfaction ; 
whence their Spanish name of ézho (the aspirate being dropped 
in that language). They also have another cry somewhat resembl- 
ing a Heron’s, which I only hear them utter after night-fall. But 
in a wild state their cries are peculiarly fascinating and varied, 
and many a night in the hot summer evenings in Spain have 
I listened with delight as these grand birds uttered their wild, 
melancholy, hollow calls which echo and re-echo along the rugged 
cliffs and gorges in which they spend their joyful existence. 
