298 STUDIES IN BIRD-MIGRATION 



only a few are seen in November and December. 

 Numbers appear early in January, and spend all their 

 time afloat, no matter how stormy the weather may be 

 (Tomison). 



Mergus serrator, Merganser. — Mr Tomison only 

 once saw this bird, and there have been no other 

 instances recorded since he left the island. 



Crex crex, Corn-Crake. — Occurs regularly in May 

 and occasionally in September. In spring the earliest 

 date for its appearance is 3rd May, and the last for 

 the autumn 25th September. According to Mr Tomison, 

 it is seen in June and July, but does not nest, and 

 rarely '' crakes." 



Rallus aquaticus. Water - Rail.- — -Mr Tomison 

 several times observed this bird in winter. One is 

 recorded as having been seen on 20th June 1909. 



Gallinula chloropus, Waterhen. — One was killed 

 at the lantern on 12th April 19 10. 



Charadrius pluvialis. Golden Plover. — Occurs on 

 passage in both spring and autumn. The spring 

 records for its flights northwards date from 2nd April 

 to 3rd May ; and the return autumn movements have 

 been witnessed from 20th August to 30th November. 

 Large flocks are heard passing at night during the 

 latter season, and many fly around the lantern, but Mr 

 Tomison has only known one bird to strike. Few are 

 seen on the island during the daytime. 



Squat AROLA helvetica. Grey Plover. — I saw a single 

 bird on the island on 22 nd September 1904 — the only 

 record. 



Vanellus vanellus, Lapimng. — Occurs regularly, 

 but in small numbers only, during the spring and 

 autumn passage movements. In spring it has appeared 



