NESTLESS BIRDS AND ANNEXERS 51 



and the Purple Crackle have been known to build 

 amongst the sticks of an Osprey's nest. In Asia 

 Minor colonies of Spanish Sparrows (Passer salicicolo) 

 have been observed in Storks' nests, almost every 

 interstice in the great stick-built nest of the Stork 

 containing one of the Sparrows, some fifty nests of 

 the latter being accommodated amongst the material 

 of each one of the former. It seems fitting here 

 also to allude to the fact that some birds are in 

 the habit of returning to the old nest season by 

 season, and using it annually for purposes of re- 

 production. No more familiar instances could be 

 given than those of the Rook, the Starling, and the 

 House Sparrow. Here, again, we are confronted by 

 another of those as yet inexplicable facts relating 

 to the science of nests. Why, we may naturally 

 ask, do some species retain an unquenchable love 

 and affection for the old nest, returning to it each 

 season of reproduction, patching, repairing, and 

 adding to the structure as the time for its use 

 comes round anew, whilst the majority of others 

 desert it for ever as soon as it has served its 

 purpose ? 1 may, however, state that the species 

 that so return are mostly gregarious during the 

 season of reproduction ; whilst the fact must not 

 be overlooked that the majority of birds show a 

 considerable amount of affection for the locality in 

 which they rear their young. Every observer of 

 birds must have had some experience of the manner 



