19G STUDIES IN BIRD-MIGRATION 



to sojourn in England before finally departing for their 

 southern winter-retreats. 



Further Observations on the Aut2imn Movements. — 

 At the best stations for observing the emigration of the 

 Swallows from our shores, it usually takes the form of 

 the continuous passage of small parties not exceeding a 

 score, and as this may last for hours, vast numbers thus 

 depart. They have, however, been observed to assemble 

 on the south coast in thousands and fly away en masse, 

 but it is only occasionally such departures are re- 

 corded. The earliest troops to cross the Channel are 

 composed of old and young birds. It has, however, 

 been noticed that the large congregations at various 

 points on the south coast, whether preparing to emigrate, 

 or in actual movement, consist in some instances chiefly 

 or entirely of young birds, and in others wholly of adults. 

 More frequently, however, the number of old birds is in 

 normal proportion to that of the young. Swallows are 

 frequently seen emigrating in company with House- 

 Martins and occasionally with Sand-Martins. 



The flittings-away of the Swallows which have 

 summered in the British Isles, and of those which visit 

 our shores as birds of passage proceeding southwards, 

 are mainly undertaken during the daytime. On the 

 south coast some of the great movements are recorded 

 as in progress from early morning until noon, others 

 proceeding until night sets in.^ There are records, 

 however, of night movements. Thus, at the Casquets, 

 west of Alderney, on ist October 1880, Swallows, with 



^ At the Nab lightship, ist October 1886, Swallows were recorded as pass- 

 ing south at intervals, twenty at a time, from dawn to dark. The returns 

 from Hanois lighthouse, on the west coast of Guernsey, show that Swallows 

 pass southward from 6 a.m. to 8 P.M. 



