THE WILLOW-WRENS OF A LOTHIAN WOOD. 407 



average nearer the song-centres. No doubt in this respect, as 

 in others, environment is not without effect on the habits of 

 the birds. 



It may, perhaps, be not altogether superfluous to give from 

 my notes one or two short extracts, selected as illustrating 

 different points in the relationship of neighbouring pairs of 

 birds : — 



" May 20th, 11 a.m. : Watched Willow- Wren building. The 

 situation chosen for the nest is apparently outside the male's 

 territory, since on all previous visits he was never observed to 

 approach nearer than a point some fifteen yards distant. To- 

 day, however, he was notably much more restless than usual, 

 being incessantly on the move, and frequently visiting spots 

 previously unknown to him. ... A third bird (female ?), during 

 the half-hour I remained, was frequently feeding quietly within 

 a few yards of the nest. Though it could not but be visible to 

 the other birds, no attention was paid to it. 



" May 21st, 3.30 p.m. : . . One bird, whose usual singing-post 

 is in a wild cherry-tree, was observed to fly straight into the fir- 

 clump, fifty yards away, which is the central point in the neigh- 

 bouring bird's territory. Here it remained for some minutes, 

 singing quietly, and then returned without molestation. 



" May 20th, 3.50 a.m. : . . . Once the male from the next 

 territory had penetrated almost to the quarry (the song-centre 

 of male No. I.). Male No. I. soon noticed him, and pursued him 

 instantly, chasing him for a long distance beyond his own 

 territory. 



" May 24th, 3 p.m. : Two pairs of birds watched. The males 

 were frequently in close proximity to each other. On one occa- 

 sion they were singing in two neighbouring trees whose branches 

 interlaced. No jealousy shown. The female of pair No. I. 

 several times wandered into the territory of the other pair, and 

 once passed right through it to some unoccupied ground on the 

 other side. This bird was watched building her nest — which is 

 still unlined — in the top of a high bank within a few yards of the 

 favourite tree of male No. II. Male No. I. kept in fairly close 

 attendance on her, occasionally uttering the buzzing note, and 

 passing from tree to tree in sluggish flight." 



