278 SWALLOWS AND MARTINS 



2. Distribution. The ordinary European swallow is found in the breeding 

 season throughout Europe, except in the extreme north, beyond lat. 70 N., North- 

 west Africa, and the greater part of Western Asia, but is replaced in North-east 

 Africa, Palestine, Eastern Asia, and North America by other sub-specific forms. 

 In the British Isles it is very generally distributed, but becomes scarcer in the north 

 of Scotland, although it has been known to breed occasionally in the Orkneys and 

 Shetlands. It is, however, only a straggler to the Outer Hebrides, but has once or 

 twice bred on Barra and once on the Uists. During the winter months it is met 

 with on migration over all Africa as far as Cape Colony, and in Asia to India and 

 the Malay Peninsula, but does not winter north of the oases in the Sahara as a 

 rule. [F. c. R. jr.] 



3. Migration. A summer visitor and bird of passage. Dr. Hartert holds 

 that " without doubt the most northerly dwellers migrate farthest south, while the 

 breeding birds of the Atlas Mountain region probably go only to the oases of the 

 Sahara to pass the winter" (Vdgel der paladrktischen Fauna, i. p. 801). The 

 British migrations of the species have been very thoroughly studied, and this 

 summary of the results is based principally on the special report on the swallow 

 drawn up by Mr. W. Eagle Clarke for the Migration Committee of the British 

 Association (Brit. Assoc. Report, 1901, pp. 372-76, being pp. 9-13 of the Fourth 

 Migration Report). The different movements may be best treated separately. 



(1) Spring immigration of our summer resident birds. Swallows have been 

 recorded as present in some numbers on the 21st of March (cf. Saunders, III. Man. 

 B. B., 2nd ed., 1899, p. 163), but it is usually only solitary birds that come to notice 

 during that month. It is characteristic of the swallow, in fact, that the arrival of 

 the " main body " is heralded by a few early individuals. The date of arrival, 

 however, varies greatly in different parts of the country. " A careful analysis of 

 dates shows that the average time of [the vanguard's] appearance ... is as follows : 

 For South-western England, the beginning of the first week [of April] ; for Ireland, 

 the end of that week ; for South-eastern England, early in the second week ; for 

 South-western Scotland, the end of the same ; for South-eastern Scotland, the 

 middle of the third week ; for Northern Scotland, the fourth week ; and lastly, it is 

 not till the second week of May that the few swallows which resort to Orkney reach 

 their destination. These early immigrants are either single birds or pairs. Some 

 ten or twelve days later than the arrival in each case of this advanced guard takes 

 place the appearance of swallows in some numbers, and they become gradually 

 abundant throughout the kingdom. These initial hosts are followed by others, 



