ON lURD MIGRATION. 373 



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, and so the influx proceeds during the rest of April and the first 

 half of May, and beyond that date in the case of birds of passage. In 

 backward seasons, such as that of 1887, when cold and unsettled weather 

 with snow and sleet prevailed, the vanguard may be delayed for about a 

 week, but on that occasion its appearance was immediately followed by a 

 ' rush,' and the birds became numerous and general only a little in arrear 

 of their accustomed time. In the Hebrides and North-western Scotland 

 the Swallow is uncommon, and mostly observed on passage in small 

 numbers, while though appearing almost annually in Shetland, chiefly 

 after the middle of May or early in June, it is little more than a straggler. 

 In Ireland the immigrants arrive in considerable numbers until about 

 the middle of May, and in some seasons (1883, 1884, and 1886) so late as 

 the third week of that month, but it is possible that some of these later 

 birds are on passage to tlie Hebrides and north of Scotland. 



It is evident from the statistics consulted that the arrival of Swallows 

 on the western seaboard is well in advance of their appearance further to 

 the east. Not only is this so in the south of England, but even in Scot- 

 land the districts of ' Solway ' and ' Clyde ' almost invariably receive their 

 Swallows several days (some seasons ten or eleven) before the ' Tweed ' and 

 ' Forth.' 



Swallows are described as arriving on our southern shores during the 

 daytime, chiefly in pairs, but sometimes as many as six or seven together, 

 and flying low over the sea, the immigration lasting most of the day ; but 

 they are also noted as coming in small parties, flock after flock, for several 

 hours in succession, and unaccompanied by any other kinds of birds. A 

 remarkable exception to this was, however, observed at the Eddystone in 

 1887, when from midnight to 3 a.m. on May 3 and 4 hundreds of birds. 

 Swallows and Wheatears, together with (as testified by the wings of the 

 victims) Reed-Warblers, Whitethroats, Wood- and Willow-Warblers, 

 and Redstarts were killed at the lighthouse. Generally, however, few 

 Swallows meet with disaster during their spring journeys, a very small 

 number striking the lanterns, while fewer still seem to suffer from exhaus- 

 tion. 



Sjyring Passage from the South to Northern Europe. — This movement 

 of Swallows which pass along our coast-line on their way to their homes in 

 the north of Europe does not set in till the last days of April, reaches its 

 maximum about the middle of May, and may be prolonged till nearly the 

 middle of June. Many of the earlier of these transient migrants reach 

 our south coast in couipany with the Swallows that come to summer with 

 us, but those which pour in during the latter part of May or in June are 

 mostly passengers on their way to Scandinavia. '^ The stream is almost 



' According to the information of Professor Collett, the Swallow is seldom 

 observed in Norway in April. In the first week of May examples appear singly, 

 about the middle of that month more arrive, and between the 20th and 25th all, 

 perhaps, are coine, 



