18 REPORT ON THE MIGRATION OF BIRDS. 



Raven occasionally seen there in March, April, September, 

 October, and November, always one, two, three, or four, and 

 therefore probably birds breeding, or reared on 1ST. Unst main- 

 island. In the same way Eavens occasionally seen at 1ST. 

 Ronaldshay, Pentland Skerries, etc., can only be looked upon 

 as " on predatory quest intent." 



" Black Crows " at N. Unst are probably Rooks, usually 

 " flying south " (if they come from E. turning south no doubt at 

 Unst). We would like to feel sure if these Black Crows are 

 Carrion Crows or Rooks ; but " Rooks " by name are never 

 mentioned at 1ST. Unst. Indeed, " Rooks " by name are only 

 mentioned by reporters from Pentland Skerries and Fidra, but 

 " Black Crows " and " Crows " seem to have general application 

 even at Isle of May. We would like Rooks distinguished from 

 Carrion Crows or Corbie Crows. The terms " Crows " and 

 " Black Crows " might mean either the Carrion Crow or the 

 Rook. [Those who have Johns' book will easily see the 

 difference. — J. A. H.-B.] Considerable movements all through 

 the year, extending from N". Unst southwards, of Hooded Crows 

 and " Black Crows " and Rooks. Jackdaws visited Isle of May 

 in a fog in April, and stayed all night of the 11th ; and two had 

 previously been seen on March 19th. Noticed also occasionally 

 at Fidra. Heaviest appearances of Corvidce in October when 

 migration was almost continuously heavy ; lightest, however, at 

 1ST. Unst; heaviest at Pentland Skerries 5th to 11th October. 

 Continuous but much lighter returns from N. Unst, N. Ronald- 

 shay, Pentland Skerries, and Fidra, in September, and curiously, 

 none from Isle of May. Light returns again from N. Unst and 

 Fidra in November, and only two from Pentland Skerries in 

 December. 



The uniformity of time in rushes of almost all species is 

 singular this season, October being the favoured month. 



Cypselid^e. — Swifts. — [" Swallow Swift " of Isle of May re- 

 turns.] — In spring or summer three " Swallow Swifts " at Isle 

 of May, light, W., clear. No other records, except one on 3d 

 May at same station. 



In Autumn. — Two Swifts at Pentland Skerries catching 

 insects round the tower; light, S.W. 



CucuLiDiE. — Cuckoo. — Only one notice at Isle of May on 

 18th May. 



