xlii INTRODUCTION. 



Visitants, the Bearded Reedling, Crested Titmouse, Lesser 

 Grey Shrike, Ortolan Bunting, Chough, and Golden Eagle 

 are noticeable as of exceptionally rare occurrence. 



The species excluded from the Yorkshire list are placed 

 between square brackets, in their proper order, and although 

 their claims to a place in the county fauna must be regarded 

 as inadequate, it is quite possible that further investigation 

 may show some of them to have been genuine occurrences. 



Two species which have occurred in Yorkshire — the 

 Cuneate-tailed Gull, and Bulwer's Petrel — have not been 

 known to visit any other British locality, and the one last 

 named, until the year 1903, had not even occurred elsewhere 

 in Europe. 



The Cuneate-tailed Gull is specially interesting from its 

 extreme rarity ; and although there is a discrepancy of 

 dates in the two versions published at the time of the occur- 

 rence, there is no ground for doubting its genuineness. 



[The Blue-tailed Bee-eater, hitherto recorded as a Durham 

 specimen, actually occurred in Yorkshire ; no other instance 

 is known of its appearance in Europe.] 



Amongst the species which have occurred in this county, 

 of which very few British examples are known, may be cited 

 the Rock-Thrush, Orphean Warbler, White-spotted Blue- 

 throat, Lesser Grey Shrike, Tawny Pipit, Pine Grosbeak, 

 White-winged Crossbill, Eagle Owl, American Bittern, Red- 

 breasted Goose, Ruddy Sheld-duck, Buffel-headed Duck, 

 KingEider, Steller's Duck, Broad-billed Sandpiper, Gull- 

 billed Tern, and White-winged Black Tern. 



Treating of Yorkshire birds generally, it may be remarked 

 that many resident birds are to a greater or less extent migra- 

 tory, shifting their quarters from one locality to another 

 according to the season, as for example the Curlew, which 

 breeds on the high moors in the summer and retires to the 

 shores during the winter, while the Thrush, Pied Wagtail, and 

 others remain through that season in much reduced numbers. 

 Such a circumstance, however, would not in the least militate 

 against the claim of the species to be considered as resident. 



On the other hand, there are species — true winter visitants, 



