i9i3- I 9 I 4-] A Pair of Long-Eared Owls. 65 



hardly explain cases where reoccupation has taken place after 

 a lapse of many years, as when a pair of Golden Eagles take 

 possession of an old nesting site which has not been used for 

 half a century, nor will it explain the choice of the original 

 pair, the founders of the dynasty. Personally we believe 

 that birds are far more sensitive to their breeding environ- 

 ment than is generally supposed, and a nesting site or nest- 

 ing haunt is chosen by a species because it meets certain 

 instinctive requirements of that species, requirements, more- 

 over, which only certain natural areas can supply, and the 

 motives which determined the choice of the first pair might 

 easily determine the choice of a second irrespective of blood 

 relationship. We know that every cliff and every wood is 

 not the same to a species, and the same distinctions are often 

 recognised by the bird man himself. He may be neither 

 a forester nor a botanist, and yet, upon entering a certain 

 coniferous wood, say at once, " This is a wood for Sparrow- 

 hawks." He could not tell you why he thought it a wood 

 for Sparrow-hawks, could not probably explain how it differed 

 from half a dozen other coniferous woods where he would 

 make no such pronouncement ; he only knows that this is the 

 kind of wood which a long experience has led him to asso- 

 ciate with Sparrow-hawks ; in a subconscious way he has 

 begun to appreciate the Sparrow-hawk's distinctions. 



The wood in which we watched the Long-eared Owls lies 

 in the rich arable land of West Lothian, extends to about 26 

 acres, and comprised, at the time of our observations, roughly 

 three zones of coniferous timber — first, an L-shaped belt of 

 densely-planted Scots pine and spruce ; secondly, occupying 

 the larger part of the wood, and lying within the arms of the 

 L, a fairly thick plantation of young firs ; and lastl} 7- , in the 

 north-west corner of the wood, a scattered group of old Scots 

 pines. It was this Corner of old pines which the Long-eared 

 Owls used as their nesting quarters. Apparently it possessed 

 some quality or qualities which the rest of the wood lacked. 

 It may have been the more open canopy, the easier access to 

 the surrounding fields ; it may have been the height and age 

 of the trees ; it may have been all or any of these things in 

 which the Corner differed from the rest of the wood, things 

 which can be tabulated as giving the Corner a distinctive 



