52 REPORT ON THE MIGRATION OF BIRDS. 



have observed, for two years in succession, that the streams of 

 small migrants from Scotland follow those main valleys which 

 run nearest north and south, sticking closely to the lowest 

 levels, where the brushwood and bracken beds offer greater 

 privacy and security than the bare fell sides. Birds also, when 

 migrating, follow from choice low-lying tracks of land and river 

 courses in preference to elevated plateau and the summit line 

 of mountain ranges. 



Bearing these facts in mind, we find that there is a very well- 

 marked line, both of entry and return, at the Earn Islands, on 

 the coast of Northumberland. Scarcely second to this is the 

 mouth of the Tees, both in spring and autumn. The North 

 Yorkshire coast, from south of Bedcar to Flamborough, including 

 the north side of the headland, is comparatively barren, few birds 

 appearing to come in between these points. Bridlington Bay 

 and Holclerness to Spurn and Lincolnshire, as far as Gibraltar 

 Point, give perhaps the best returns of any on the East Coast. 

 The north of Norfolk is poor, but there are indications in the 

 heavy returns annually sent from the Llyn Wells, Dudgeon, 

 Leman and Ower, and Happisburgh light-vessels, that a closely 

 focussed stream pours along the coast from E. to W., to pass 

 inland by the estuary of the Wash and the river systems of the 

 Nene and Welland into the centre of England, and thence pro- 

 bably following the line of the Avon, the north coast of the 

 Severn, and Bristol Channel, and eventually striking across the 

 Irish Sea, to enter Ireland near the Tuskar Bock, off the 

 Wexford coast. This route is undoubtedly the great and main 

 thoroughfare for birds in transit across England to Ireland in 

 the autumn. Large numbers of migrants also which pass 

 inland from the coasts of Holderness and Lincolnshire may 

 eventually join in with the great western highway by the line 

 of the Trent, avoiding altogether the mountainous districts of 

 Wales. These remarks will refer chiefly to the Passerine birds, 

 the Accipitres, Limicolce, and Gavice, also Geese and Ducks, 

 when crossing land, travelling as a rule very high. 



To return once more to the East Coast, the Norfolk seaboard 

 between Cromer and Yarmouth and the corresponding light- 

 vessels show a large annual immigration, but the returns are 

 less pronounced between Yarmouth and Orfordness. The coast 

 of Essex, with the northern side of the Thames estuary, is fairly 



