426 BIRDS OF THE WEST OF SCOTLAND. 



informed us that he had that morning found another in the nets, 

 but having tethered it to a stone until his work was finished, he 

 could not again find it. From repeated observation on Ailsa Craig 

 T have computed that not more than one ringed bird in five 

 hundred of the common ones can be recorded from that locality. 

 From Mr Harvie Brown's journals, I learn that on the island of 

 Handa, on the west of Sutherlandshire, the proportion is one in a 

 hundred. Again, at Barra Head, I have been assured by the 

 lighthouse keeper, the number may be reckoned at one in fifty ; 

 but Mr Elwes, who spent four days there in the summer of 1868, 

 and was at some pains to ascertain the exact proportion, states 

 that he counted the guillemots as they flew past the cliff on which 

 he sat, and found one in ten or twelve. A later and more pains- 

 taking investigation has been made both at Barra and on the 

 comparatively little known and seldom visited Stack of Lianamull, 

 off the island of Mingalay, by Captain Feilden and Mr Harvie 

 Brown, whose full and most interesting journals have been 

 obligingly placed at my service, and I have the pleasure of 

 inserting here the following result of their observations: " On 

 Barra we came to the conclusion, after the most careful scrutiny, 

 that the proportion of bridled birds is one in five. We examined 

 seven ledges on Barra and one in Mingalay, and after we had both 

 in turn counted and recounted, the particulars now furnished may 

 be accepted as accurate notes taken on the spot: 



1st Ledge 28 birds in all, of which five were bridled; two bridled 

 birds were paired, and were trimming each other's 

 feathers; and another pair, a male of the common 

 guillemot and a female ringed bird, were observed 

 in copula. 



2d 29 birds, of which five again were bridled. 



3d 12 birds, of which three were bridled. 



4th 16 birds, of .which four were bridled. 



5th 10 birds, of which only one was bridled. 



6th 21 birds, of which four were bridled. 



7th ,, 4 birds, of which two were bridled; of these two we 



obtained the eggs identified. 



8th 4 birds, of which one was bridled, and we again ob- 



tained the egg (this ledge was on Mingalay). 



Total, 124 birds, of which twenty-five were bridled. 



