346 Wonders of the Bird World 



in times long past, when land-passages existed, which are 

 now buried beneath the ocean. This may account for the 

 arrival in winter of many species in Britain which come 

 across the North Sea. It may also account for the way in 

 which the Wheatear {Saxicola cenanthe) reaches Greenland 

 every year, and for the occasional appearance of the Land- 

 Rail and Peewit in North America, and of the Ruff in 

 Barbados. The most wonderfully suggestive instance, 

 however, is, to my mind, the occurrence of the two species 

 of Red-footed Kestrel in Southern Africa. It is well 

 known that in certain parts of Africa, during the northern 

 winter, vast flocks of birds of prey are observed. They 

 consist of Kites, Eagles, Hobbies, Kestrels, etc., and they 

 follow the swarms of locusts, or appear in numbers where 

 grass-fires take place. The European Red-footed Kestrel 

 (Erythropus vespertinus) nests in South-eastern Europe, and 

 is found in South-western Africa (Damara-land and the 

 adjacent countries) in winter. In Eastern Siberia occurs 

 the second species of Red-footed Kestrel (Erythropus 

 amurensis\ which is exactly like the European bird, except- 

 ing that the under wing-coverts are white instead of grey. 

 It is, however, a perfectly distinct species, and winters in 

 South Africa also, but in the more eastern districts, such 

 as the Zambesi region. Occasionally the two species have 

 been found inhabiting the same area in their winter 

 quarters, but, as a rule, it would seem that they preserve 

 there a similar eastern and western distribution to that which 

 characterizes their breeding habitats. The question is 

 How does Eyrthropus amurensis reach its winter quarters ? 

 Not, apparently, by the Nile Valley and the country of the 

 Great Lakes, which is the route apparently taken by the 

 European Red-footed Kestrel, along with the Hobby and 

 the Common Kestrel. It would appear, therefore, that it 

 must cross the Indian Ocean in a direct south-westerly 

 flight, and this is probably the case. A few stray examples 



