208 Among the Birds in Northern Shires. 



marked preference for rivers; the Pintail is a third. 

 Companies of Swans from time to time may be 

 observed, usually consisting of Whoopers, and much 

 more rarely of Bewick's Swans. 



During the migration season in spring, and more 

 especially in autumn, these northern river-valleys are 

 frequented by great numbers of land birds on their 

 way to more northern and eastern breeding-grounds 

 in Continental areas, or returning south and west to 

 winter in our islands or to cross over them to warmer 

 latitudes. These northern rivers are exceptionally 

 favourable for migration, so many of them trending 

 in the same general direction as the birds are bent 

 on following. Vast numbers of migrant small birds 

 follow such river-valleys as the Tees and the H um- 

 ber, on their way into Yorkshire, Notts, and Derby- 

 shire, by way of the Don and its tributary streams. 

 It is unnecessary here to dwell upon these species 

 in detail, for we hope to go much deeper into the 

 matter when we come to a study of the migration 

 of birds in the northern shires. We have gathered 

 much evidence in support of this migration during a 

 residence of many years at no great distance from 

 the H umber and certain valleys in direct communi- 

 cation with that important estuary next, perhaps, 

 in interest, so far as bird-life is concerned, to that 

 still more wonderful locality the Wash, a little lower 

 down the coast. 



