154 STUDIES IN BIRD-MIGRATION 



June. In 1910 it appeared at intervals in exceptional 

 abundance from 13th May to 23rd, with single birds 

 down to 3rd June. 



In autumn there are three records only for the years 

 1905 to 1909 inclusive, and these relate to the occurrence 

 of single young birds observed on 20th August and ist 

 and 2nd September. During August 1910, however, 

 there are five records of visits from the i6th to 26th. 



Cypselus apus, Swift. — Swifts appear annually on 

 both passages, but, like the species of Hirundinidae and 

 some others, are more numerous in springtime than in 

 autumn. In 1910, howe-\fer, the honours seem to have 

 been pretty evenly divided between the seasons. 



The earliest record for its appearance in spring is on 

 8 th May — a very early date for Shetland — the next 

 in order being for the 23rd. After the last-named date 

 the bird as a rule is most in evidence, usually in small 

 numbers, until the end of the month. Occasionally 

 many appear in rushes with other species. There are 

 numerous appearances for June and July on the part 

 of a few or single birds. 



In autumn one or two arrive at intervals during 

 August and the first half of September, but I saw a 

 single bird on 3rd and 4th October in 1909. 



Caprimulgus europ^us. Nightjar. — There are, as 

 yet, only two records for the visits of this species. On 

 24th May 1 9 10, one was observed on heathery ground 

 by the Duchess of Bedford ; and on 21st August 1908 

 the remains of one which had quite recently perished 

 were found. 



Upupa epops. Hoopoe. — There are three known 

 instances of the visits of single birds of this beautiful 

 species. An adult male appeared on 9th September 



