APPENDIX. 361 



Abundant on Hancla and elsewhere, such as Cearvig Bay and Cliffs 

 of Clomore, etc., on the north coast. The annual reports of the Com- 

 mittee on Migration of Birds for the British Association show with 

 what marvellous regularity they appear at their various breeding- 

 stations, and then leave again in autumn, along with other rock-birds. 



Common Guillemot Lomvia troile (Linn. ) 



Occasional visitant on the east coast, especially in winter and spring, and 

 often thrown up dead after a storm. 



Rock -birds breed plentifully on the Caithness side of the Ord, but 

 never on the Sutherland side. 



When Guillemots or Razorbills are observed swimming near the 

 shore in winter on the east coast, they are generally, if not always, 



weakly birds, and probably perish. 

 Exceedingly abundant on Hanc 



Exceedingly abundant on Handa ; the summit of the Stack and the 

 regular niched ledges of the cliffs literally swarming with life. 

 The bridled or ringed variety (U. lacrymans or U. ringvia) is in propor- 

 tion to the others as one or two in every ten or a dozen. The iden- 

 tity of those forms has been placed, by us, beyond doubt. The 

 regularity of the migration from east to west in autumn at all the 

 north coast lighthouses, and the dates of commencement and comple- 

 tion, are interesting (see Migration Reports, 1879-1883). 



Black Guillemot Una grylle (Linn.) 

 A spring visitant to the east coast. 



Breeds not uncommonly on the west coast, and in a colony on the 

 Badcall Islands. Once plentiful on Handa, now rare, if indeed present 

 at all, and the cause assigned for extinction by the cragsmen the 

 Brothers Mathieson is that rats have managed to dislodge them. 

 "We have found that the males assist in incubation, having one or two 

 hatching spots on the breast, and these have been taken off the eggs. 

 They are abundant also along the north coast, west of Loch Erriboll. 



Little Auk Mergulus alle (Linn. ) 

 Winter visitant, but not occurring every year. 



Puffin Fratercula arctica (Linn.) 

 Winter visitant to the east coast. 



The principal colonies of these birds on the west and north are : 

 Handa, about three miles of cliff and slopes east of Cearvig Bay, 

 occupied in many places from base to summits, which are 380 feet in 

 height a marvellously fine colony at Clochbheag, near Durness, 

 and scattered colonies at other points. They used to breed at Garbh 

 Island numerously, but are now rare there ; having been persecuted, 

 they have taken to the higher cliffs of Clomore and Cearvig. Rats 

 have also driven them off the tops at Handa into more secure crevices 

 in the face and slopes. 



STEGANOPODES. 



Family PELECANID.E 



Gannet Sula bassana (Linn.) 



An occasional visitant to the east coast; not rare; old birds most 

 abundant. The regular streams of migration of the Gannets round our 

 islands are worthy of attention ; flying east and north along the north 

 coast in spring, and flying west daily in autumn. Between 2150 and 

 3080 have been estimated to fly westward within view of Cape Wrath 

 during fifteen days noted, between 14th July and 9th August. They 

 pass between 7 A.M. and 10 P.M. each day, in all winds and weathers. 

 (See Migration Report, 1879, p. 41.) 



