xxxviii INTROD UCTION. 



other parts of the British Isles is not improbable, even 

 though their visits may be very few and far between ; and also 



ACCIDENTAL VISITANTS, mere waifs and strays species 

 whose geographical range renders their occurrence in Britain 

 quite exceptional and more or less remarkable. 



These definitions have been carefully framed, and will, it is 

 believed, be found applicable to all cases. A few general re- 

 marks upon them, illustrated by characteristic examples, desir- 

 able in order to make their meaning perfectly unmistakable, 

 will be given in proceeding to analyse the Yorkshire fauna. 



The avifauna of Yorkshire, compared with that of other 

 counties, stands unrivalled, not only in its numerical extent, 

 but also a circumstance of much greater significance in 

 the inherent richness which is shown by the number of species 

 breeding annually within its limits. 



Excluding twenty-one species, which have been recorded 

 on the strength of evidence more or less insufficient to establish 

 their claims, the total number of birds on the Yorkshire list 

 is 325. The Norfolk list, given in " Trans. N. and N. Nat. 

 Soc." (1885, 1886, 1887), included 288 species to which 

 must be added 27 which have occurred in the county 

 since that time, for the names of which I am indebted 

 to Messrs. J. H. Gurney and Thomas Southwell of Norwich, 

 making a total of 315. The list given in Hancock's " Birds 

 of Northumberland and Durham," published in 1874, com- 

 prises 268 species. But applying the same rules as are 

 employed for the exclusion of doubtful species from the 

 Yorkshire list, the total is reduced to 266 for Northumberland 

 and Durham. 



Since the publication of Hancock's catalogue, however, 

 the following species must be omitted from the list : the 

 Purple Gallinule, Virginian Colin, Egyptian and Canada 

 Geese, and the Blue-tailed Bee-eater (which latter occurred 

 in Yorkshire, see p. 284). Eleven additional species which 

 have occurred in Northumberland and Durham are : the Tree 

 Warbler, Icterine Warbler, White Wagtail, Rustic Bunting, 

 Little Bunting, Alpine Swift, Spotted Eagle, Crane, Red- 



