On Bmt) MIGRATIO?^. 371 



during the latter half of February, and occasionally as early as the second 

 week (in 1886 on the 11th), the immigration continuing throughout 

 March. The precise time seems to be influenced by the condition of 

 the weather in the birds' southern retreats. If the early spring there be 

 mild and genial, they begin their return early, but if the contrary their 

 departure is delayed. On arrival on the south coast of England many 

 pass northward along the east and west coasts, the latter being the 

 route chiefly followed by the earlier immigrants. The return to Ireland 

 corresponds closely with the arrival in Southern England, the earliest 

 observation for the period 1882-87 being on Fel)ruary 10, 1886, and from 

 that time the movements occur at intervals. The other species of birds 

 which reappear along with the Skylarks are mostly those which have before 

 been mentioned in association with them — Thrushes, Blackbirds, Titlarks, 

 Lapwings, and so forth. During April the movements of the immigrants 

 become merged into those of the strictly called Birds of Passage. In Ireland, 

 during the first half of the month and occasionally to the third week' 

 Skylarks continue to arrive in company with Wheatears and other early 

 summer birds. The return movement to the Hebrides corresponds with 

 that to the mainland, but, as in Ireland, the immigration is prolonged into 

 April. In Shetland the spring arrival of the native birds begins in the 

 early days of March. The immigrants reach the south coast of England, 

 sometimes in vast numbers, during the earliest hours of the morning, but 

 in the south-east of Ireland, the chief point of arrival in that country, 

 they are usually observed later in the day, but in the Hebrides at 

 night. 



8. Sjn-ing Emigration to Central Europe from the British Isles. The 



return (west to east) movement from South-eastern England across the 

 North Sea comes very little under observation compared with the in- 

 flowing streams of the preceding autumn, and that this should be so is 

 easily to be explained. In the first place, the numbers of travellers, owino- 

 to the waste of winter, have been much thinned ; and secondly, because" 

 like all other important emigratory movements, this one takes place chiefly 

 at night, and so for the most part escapes notice, for it is reasonable 

 to suppose that the first hour of flight takes the birds beyond the limit 

 of observation at the Light-stations along our eastern coast. Some return 

 emigration is nevertheless observed by day on the Lightships, the direc- 

 tion of the birds being eastward from the mouth of the^Thames, and south- 

 eastward from the more northerly stations. There are also enough observa- 

 tions to show that the movement begins in February (in the mild season 

 of 1882 on the 6th, but usually not till the middle of the month), and is 

 continued until the end of March, the 28th being the latest day recorded. 

 As with the reverse movement in autumn, this is chiefly noticed on the 

 Lightships between the Thames and the Humber. The other species of 

 birds accompanying the Skylarks are Starlings, ' Crows,' and Lapwino-g. 



9. Spring Migration to Northern Europe from the British Isles —lu 

 mild seasons during the third week of February tliere are indications at 

 our north-eastern stations that the Skylarks which have wintered with 

 us are beginning to depart for their northern homes, and throughout 

 Marcii, especially after the middle of the montli, there is usually much 

 evidence to the same effect, the concomitant species beino' Blackbirds. 

 Uoldcrests, Starlings, Woodcocks, and ' Wild Geese ' ; but here, a" ain as 

 in the last case, much escapes notice, and for the same reasons. 



The spring emigration from Ireland deserves separate consideration. 



B B 2 



