100 BIRDS. 



short of ten thousand, quite four hundred are alleged, and 

 seven - eighths of them probably with justice, either to 



reside in or to visit the British Islands. 

 birds* 1 These are found on analysis to fall, roughly 



speaking, under five categories : (i) The resi- 

 dents (which may or may not perform certain consider- 

 able migrations within these islands) ; (ii) the regular 

 summer (breeding) visitors; (iii) the regular winter vis- 

 itors (from the Northern seas); (iv) those which are 

 with us for a short time only on passage to and from 

 remote breeding-grounds (in spring or autumn, or both) ; 

 and (v) the casual migrants, including rare stragglers. 

 (These various categories are indicated by types and signs 

 in the following pages.) It is found convenient for some 

 purposes to subdivide these still further, but the above 

 will suffice for the purpose of this book. It will be noticed 

 that the line is not drawn very rigidly in the case of the 

 so-called "residents." This lenient interpretation is, in 

 fact, necessary in each case. Thus, not alone are our 

 residents continually recruited from the Continent, but 

 many so-called summer visitors have stayed through mild 

 winters, just as winter visitors, and even more commonly 

 spring visitors on migration, have stayed the summer. 

 Many of our seafowl which breed in the northernmost 

 lochs are really and to all practical purposes winter visitors 

 to the rest of these islands. A word is said on the subject 

 of migration on a subsequent page. 



Ornithologists are by no means quite agreed as to what 

 exactly constitutes a title to rank as a British bird, some 

 among them being more cautious than others in dealing 

 with evidence. The candidates for this honour that excite 

 the keenest controversy are, as might be expected, those 

 American stragglers which, it is very properly objected, 

 are likely to have travelled a considerable part of the 

 journey in the rigging of some swift liner. Those of us 

 who have made the passage of that mournful cemetery the 

 Red Sea know well how the hawks, finches, and wagtails 



