52 CLASS AVES. 



murderous bills of their other pursuers in the air. All the 

 insect population of ponds and marshes constitute the nutri- 

 ment of these volatiles. Their slight forms, little head, deli- 

 cate feet, and long tail, perpetually balanced, cause them to 

 be at once distinguished from all other birds with slender 

 bills. They are therefore with great propriety formed into a 

 small distinct family. 



The Motacilla Alba is spread throughout Europe. It is 

 even seen in Siberia, Kamschatka, Iceland, and the Feroe 

 islands. It also inhabits Africa and India. 



They form in autumn numerous flocks, which extend them- 

 selves through the fields, and withdraw, on the approach of 

 evening, into osieries and willows which border canals and 

 rivers. There they perform a noisy concert until night-fall. 

 They depart in October, and often at this period they are 

 heard passing in the air, sometimes at a very considerable 

 height, and clamouring to each other incessantly. They do 

 not, however, all migrate at this season, for some, though a 

 very few, are occasionally to be met with. They then abound 

 in Egypt, where the people, says Maillet, dry them in the 

 sand, to preserve them for the purpose of food. They are 

 also to be seen in Senegal at the same season ; but, like the 

 .swallows and quails, they disappear from thence in spring to 

 return to our climates, where they arrive at the end of March. 



These birds possess the most astonishing gaiety and light- 

 ness. They appear in flying to rest upon their long outspread 

 tail, as upon a broad oar which assists them to balance, 

 spring, and perform a variety of evolutions in the air. During 

 such sports, they are frequently heard to utter a little cry, 

 lively, clear, and redoubled, which sounds like the syllables 

 guit, guif, guit, guit, guit. They have also a soft and delicate 

 song, which, in autumn, is reduced nearly to a murmur. " En- 

 core," says Belon, in his old French, " savent rossignoller du 

 gosier melodieusement, chose qu^on peut souvente fois ouir sur 

 Ic commencement dc Thiver." The motion of their tail in 



