INTRODUCTION. 21 



depart in the autumn, are summer visitants ; those which come 

 in the autumn and depart in the spring, are winter visitants; 

 those which do not come every season, are occasional visitants; 

 and those that are seen rarely, only one now and then, are 

 accidental visitants, or stragglers. The resident birds and 

 summer visitants may both be considered as natives; because, 

 although visitants that are not hatched in the country may 

 come with those that are, there are always more of every 

 species hatched in the country than can be expected to live 

 and return to it. The winter visitants and stragglers are 

 not natives ; and the occasional summer visitants are only 

 partially so. It is common, however, to call every bird that 

 is found in Britain, without having been brought there by 

 artificial means, a British bird, and to distinguish them as 

 common or rare in their occurrence in respect both of place 

 and of time. 



The finding of food for themselves and their young is the 

 grand object to which all the organizations and the habits of 

 birds tend, when we consider them merely in themselves, and 

 without any reference to the rest of nature ; and therefore 

 these objects must be kept in view in the study of the birds, 

 and also in the arrangement of them. But almost all birds 

 can subsist on different kinds of food, and some have a very 

 great range, so that it becomes necessary to consider the 

 place where the food is found as well as the food itself, before 

 the general character and habits of the bird can be deter- 

 mined. The bill, the feet, the wings, and (though in a less 

 degree) tne tail, are the parts of the bird most essential to be 

 studied for that purpose ; but to these we must also add, the 

 strength and the spirit of the bird. The kestrel, for instance, 

 is a larger, and to common observation a stronger bird than 

 either the merlin or the sparrow-hawk, and it does not 

 appear to be much inferior in beak and claws, yet the kestrel 

 follows humbler game than these do. 



