BIRDS SEEN IN THE MAINLAND OF ORKNEY. 63 



and an adult Black-headed, had taken possession of a particular 

 dust-bin, and they were to be seen there all day and every day, 

 standing on an adjacent wall, or sitting asleep in the field a few 

 yards off. Every morning, directly it was light, some twenty 

 Black-headed Gulls came on to the lawn in front of the house, 

 and were very busy for an hour and a half picking up worms ; I 

 never saw any other species there. In the evening large flocks 

 used to assemble on the loch from the fields, and, after staying 

 there a few minutes, fly off to sea for the night. 



It was a very pretty sight watching the Kittiwakes fishing ; 

 on some days the sound was full of them. They reminded me 

 very much of the Terns in their methods. A strong north-west 

 wind was blowing, and the Kittiwakes would be swooping and 

 wheeling about ; when now and then one would mount to about 

 twenty feet, and turn head to wind ; then, after remaining 

 stationary on outspread wings for a second, would drop like a 

 stone on to its prey, sending the water up all round it, and com- 

 pletely disappearing for a couple of seconds in the spray ; then, 

 after about half a minute, it would rise again, and resume its 

 wheeling flight. 



On Oct. 5th I saw a Little Gull on a rock by the shore, and 

 on the next day two more pairs. On the 8th I saw ten together, 

 at the same place as I saw the one on the 5th. They were.* 

 evidently on migration, as I did not see them again, and they 

 were not so tame as the other Gulls. They were all in the adult 

 winter plumage. 



Richardson's Skua (Stercorarius crepidatus). — I twice watched 

 a pair of Arctic Skuas harrying the Kittiwakes, in the sound be- 

 tween Lambholm and the mainland. When hunting they always 

 seem to work in pairs, one bird dashing at the Gull while the 

 other hovers near to pick up the fish as soon as it is dropped. 

 Both pairs belonged to the dark form. A single bird I saw on 

 the 13th, close in shore, was very dark, with a somewhat lighter 

 patch on each wing ; in the dull light it looked quite black. 



Common Guillemot (Uria troile). — It is curious that I never 

 once saw the Common Guillemot off the south-east mainland, 

 whereas a few miles farther west in Scapa flow, and from there 

 south to South Ronaldshay, they were very common. 



Black Guillemot (Uria grylle). — Very numerous in the sound 



