172 STUDIES IN BIRD-MIGRATION 



few, chiefly single birds, have occurred on the autumn 

 passage, at dates ranging from the second week in 

 August to 30th November. 



Calidris arenaria, Sanderling, — A few visit the 

 Isle on passage annually, when they are usually to be 

 found on the little strip of sand which forms the head of 

 the North Haven. 



The spring visitors have been observed at dates 

 ranging from 25th May to nth June ; while those in the 

 autumn have appeared between 24th July and 27th 

 September, but are most frequent during the latter 

 month. One was obtained on 14th November 191 1. 



Machetes pugnax, Ruff. — Occurs on the autumn 

 passage, but has not yet been detected in spring. The 

 dates of its visits range from 24th August to 12th 

 September ; and four is the largest number of birds 

 observed on any single day. 



ToTANUS HYPOLEucus, Comnioii Sandpiper. — Occurs 

 in some numbers on both its spring and autumn 

 passage movements. 



In spring the visits on its way northwards have been 

 chronicled between 23rd April and i6th June, but the 

 birds are most frequent and numerous during the latter 

 half of May. 



The return autumn movements have usually com- 

 menced with September, and cease with the month. 

 In 191 1, however, odd birds appeared late in July 

 (25th earliest) and during August, and were probably 

 summer visitors leaving Shetland, where it nests in 

 limited numbers. A few have occurred some years in 

 October (as late as the 29th), and in 1908 one appeared 

 with a rush of migrants on 2nd November. 



On its passages this bird frequents the rocks and 



