INTERNAL MIGRATIONS. 155 



species in any part of the world remain absolutely 

 stationary throughout the year; everywhere im- 

 portant changes take place, and birds have to adapt 

 themselves to tl:ose changes, which in miost cases 

 involve a tem})orary removal from one district 

 to a more or less remote other district. In 

 countries where vast flights of locusts are continually 

 wandering to and fro, buxls of many species follow 

 in their w^ake to prey upon these insects ; whilst 

 in South Africa, Mr. Seebohm observed a most 

 interesting local movement of certain birds in search 

 of roasted grasshoppers, destroyed by the great 

 prairie fires. Large flights of Pratincoles {Glareola 

 melanoptera), and numbers of RuppelFs Lapwings 

 {Faiiellus melcuwptenis), and Birchell's Coursers 

 (Cursorius rz///^y), follow these fires from one district 

 to another, to feed on the abundant fare they 

 provide. The various local movements of the 

 ubiquitous Rice Bird {Dolichomjx oryzkora) of 

 North America are equally interesting ; as are even 

 these of our own House Sparrow {Passer domesticus). 

 This latter bird is subject to much local movement 

 during summer and autumn, and wanders far and 

 wide in flocks in quest of grain. The Lapwing 

 ( Fantllus cristalus), the Snipes {Scoiopax), especially 

 the Woodcock {Scoiopax rusticola), and the Sky 

 Lark {Jlauda arreiisis), may be instanced amongst 

 numerous others as British species that w^ander 

 about in winter, often in considerable numbers, in 

 quest of food. Birds of the Pigeon tribe 

 (CoLUMBiD^) are notorious wanderers ; so are the 



