16 THE WARBLERS 



distributed wherever there is cover, ranging as high as 1500 ft. in some districts and 

 being absent only from the moors and mountains. It breeds regularly in the Isle 

 of Man and the Inner Hebrides, has established itself in Lewis and been recorded 

 as nesting on Barra, while it is known to have bred in the Shetlands and possibly 

 also in the Orkneys. It has been known to nest in every county in Ireland. Out- 

 side its breeding range it winters in small numbers in the Mediterranean region, 

 but the great majority pass on into Africa, where it is very widely distributed, 

 and has been recorded from most regions in Central and Southern Africa, many 

 penetrating south to Natal and Cape Colony. [F. c. R. J.] 



3. Migration. No summer visitor to this country seems to arrive in such 

 myriads as the present species, and in consequence its movements are perhaps better 

 known than those of most. Towards the end of March the first arrivals reach our 

 shores, and during the whole of April they pass and spread through our islands in 

 great waves of uncountable numbers. During the season, on nights suitable for 

 observing bird movements, almost every lighthouse on the south coast, from the 

 Scillies in the west to Kent on the east, will simultaneously record the passing of 

 these birds in a continuous stream for hours at a stretch, and this not on one night 

 only, but possibly for ten or more days during that one month. The journey of 

 these wanderers is also noted as they pass northwards, and there seems little doubt 

 that though their course is due north their front presents an oblique line with its 

 western wing well forward. By the end of April our native birds have for the most 

 part arrived, but during the end of April and early in May an emigration may be 

 noted along our eastern seaboard. These are birds of passage, travelling N.E. on 

 then- way to N. Europe, and belong to the sub-species known as the Arctic willow- 

 warbler. (See below.) The emigrants no doubt summer in the extreme north of 

 Scandinavia or North Russia. As is the case with so many species, the return 

 migration in autumn is far more difficult to trace, and vast rushes like those in the 

 spring are never noted. Nevertheless the exodus is a steady one, and beginning 

 early in August continues apparently without intermission till early in October, 

 [j. L. B.] 



4. Nest and Eggs. Nesting place: normally on or close to the ground, 

 among grass in hedge bottoms or on bank sides. It is, however, less commonly 

 found at some little distance above the ground, sometimes in seedling conifers, ivy, 

 creepers, old nests, etc., and has quite exceptionally been recorded at a height of 

 14 to 16 ft. The nest is domed, with entrance at the side, and is built of green moss 

 with grasses interwoven, lined with grasses, a thick layer of feathers and occasionally 



