APPENDIX II. 



LIST OF SPECIES WHOSE CLAIM TO RANK AS BRITISH 

 IS DOUBTFUL. 



It is a matter of very great difficulty in many cases to 

 decide whether a species has sufficient claim to rank as 

 " British " or not. As my readers know, I am more apt 

 to err on the side of inclusion than on that of omission, 

 and I am led to do this partly through my long study of 

 the migration flight of birds. In a great many cases I 

 admit that it is simply wonderful how individuals of a 

 species have managed to wander so far from their normal 

 areas of dispersal as the British Archipelago ; yet when 

 we study their usual migrations in conjunction with their 

 habitat, much of the wonder is apt to vanish. In my 

 opinion some species have been most unfairly expunged 

 from the British list ; others have been included with 

 perhaps too little cause. Sedentary species should only 

 be admitted on the clearest possible evidence ; birds that 

 breed in the southern Tropics or south temperate zones 

 are even less likely to wander to our islands, because 

 their migrations are in every known instance remarkably 

 restricted ; aquatic species are more likely to travel long 

 distances than terrestrial species. Species that are kept 

 regularly and extensively in confinement should always 

 be regarded with grave suspicion. On the ether hand, 

 many birds of migratory habits breeding to the east or 



