LANGUAGE OF BIRDS. 263 



at Gibraltar, where eagles abound. The notes 

 of our hawks much resemble those of the king of 

 birds. Owls have very expressive notes ; they 

 hoot in a fine vocal sound, much resembling the 

 vox humana, and reducible by a pitch-pipe to a 

 musical key. This note seems to express com- 

 placency and rivalry among the males : they use 

 also a quick call and a horrible scream ; and can 

 snore and hiss when they mean to menace. 

 Ravens, besides their loud croak, can exert a 

 deep and solemn note that makes the woods to 

 echo; the amorous sound of a crow is strange 

 and ridiculous; rooks, in the breeding season, 

 attempt sometimes, in the gaiety of their hearts, 

 to sing, but with no great success ; the parrot- 

 kind have many modulations of voice, as appears 

 by their aptitude to learn human sounds ; doves 

 coo in an amorous and mournful manner, and are 

 emblems of despairing lovers ; the woodpecker 

 sets up a sort of loud and hearty laugh ; the 

 fern-owl, or goat-sucker, from the dusk till day- 

 break, serenades his mate with the clattering of 

 castanets. All the tuneful passer es express their 

 complacency by sweet modulations, and a variety 

 of melody. The swallow, as has been observed 

 in a former letter, by a shrill alarm, bespeaks the 

 attention of the other hirundines, and bids them 

 be aware that the hawk is at hand. Aquatic 

 and gregarious birds, especially the nocturnal, 

 that shift their quarters in the dark, are very 

 noisy and loquacious ; as cranes, wild-geese, wild- 

 ducks, and the like ; their perpetual clamour pre- 

 vents them from dispersing and losing their com- 

 panions. 



In so extensive a subject, sketches and outlines 

 are as much as can be expected : for it would be 

 endless to instance in all the infinite variety of 



