56 MY NATURE NOTEBOOK. 



increased nor diminished in numbers. At the same 

 times, both in autumn and spring, that the starlings 

 multiply on the marshes, flocks of jackdaws arrive 

 on a wooded hill near at hand ; for one or two days 

 a sloping stubble affords lodging to a host of travel- 

 ling pipits ; and a wave of small tits, gold-crests, and 

 tree-creepers passes through the woodlands. 



FILLING UP THE GAPS. 



It is probably from this floating surplus of last 

 year's broods that winter's casualties among the resi- 

 dent bird of each locality are made good. From the 

 ranks of the travellers our widows may obtain hus- 

 bands, and widowers select wives, while pairs drop out 

 here and there to take possession of unoccupied but 

 inviting nesting-sites. Thus, in gradually diminishing 

 numbers, the residue travel further and further north, 

 till the last of them reach the limit of their race's 

 range. No doubt, too, these last travellers are mostly 

 birds which were reared at the farthest point, while 

 those which fall out of the ranks by the way succumb 

 to the temptation most readily in the vicinity of their 

 old homes ; but that there are exceptions to these 

 rules is shown by the reappearance of birds in locali- 

 ties from which they have been absent for years. 

 The rules explain, however, how it is that, although 

 in autumn and spring large numbers of many kinds 

 of birds are passing to and fro, each district in 

 summer is always found to have just about its usual 

 complement of birds of all kinds, so that naturalists 

 can always tell where and in what numbers each local 

 species may be found. 



