78 REPORT ON THE MIGRATION OF BIRDS. 



on West Coast of Scotland the migration, though but scantily 

 observed, began on March 9th and terminated as late as May 

 17th (see 1882 Eeport, p. 57). 



The autumn migration of 1883 was pronounced, and confined 

 principally to end of October and November, of Turdidce^ Cinclidce 

 (one of which, seen at Isle of May, was afterwards described to 

 me as having no brown between the black and white of the 

 breast) ; also of Snow Buntings, Sky Larks, Eobins (small 

 numbers), Linnets, Chaffinches, Starlings, culminating in a grand 

 rush past of the bulk between Oct. 28th or 30th and Nov. 3rd. 

 The heaviest rush, observed at the time of a south wind, as 

 compared with other years, at Isle of May, was on Oct. 13th 

 and 14th, a S.E. wind, according to Mr. Agnew, being usually 

 more favourable at that point. This October to November rush 

 is undoubtedly the principal feature of our returns over the 

 whole country. Of the expansion of the fan or wave our returns 

 from both E. and W. coasts give a very fair indication. It seems 

 likely that, although most land- stations have not returned very 

 heavily-laden schedules, — not to compare, for instance, with 

 1882, — yet, as noticed by Mr. Cordeaux, quite as many, if not 

 more, birds were observed at the lightships ; that the reason for 

 this may be found in the normal and favourable direction of the 

 winds prevailing in the North Sea at the time of autumn 

 migration, resulting in greater numbers of birds passing inland 

 without resting, and being thus less liable to come under 

 observation, except at specially suitable stations. And, if we 

 / compare the schedules of 1883 and those of 1882 on the West 

 Coast of Scotland we find that, while larger numbers are 

 recorded at the more northerly stations in 1883 than in 1882, 

 there is a lighter return at more southerly stations in the autumn 

 of 1883 than there was in the autumn of 1882. Thus to no in- 

 considerable degree the order of the statistics of two years is 

 reversed. It would almost appear in this way that when a 

 ** spread fan" reaches our E. coast with S.E. winds — reaching, 

 as it did in 1882, from Faroe S. to the English Channel — the 

 birds, being tired and worn out, promptly seek shelter, and then, 

 when rested, pursue their migration on more southerly lines, and 

 do not reach so far west, except such as fail to catch up the land, 

 and are driven forward helplessly. This would cause comparative 

 desertion of the more northerly -stations of the W. coast and 



