8 FIELD-STUDIES OF RARER BIRDS 



low over the intervening ground and bushes. In 

 heather, of course, the birds are interviewed more 

 readily, and can easily be driven from their retreat. 

 The flight, though inclining to the rapid, is weak, 

 and seldom of any duration, or at a greater height 

 than from three to five feet from the ground. A 

 marked peculiarity of the flight is in the movement 

 of the tail, which is worked up and down, although 

 not too spasmodically. The lengthiest and loftiest 

 flight I ever witnessed (though, of course, when 

 the birds relinquish their summer-camp they must 

 necessarily fly further) was in a crease of the Sussex 

 Downs, when a " Dartford," desirous of vacating 

 a bed of gorse streaking the flank of a natural 

 amphitheatre, ventured to a strip of mixed 

 furze, bramble, and elders, fully a quarter-mile 

 away in the valley below. The flight was then, 

 if anything, weaker than its wont, more wavering 

 and quite top-heavy, as if the rather long tail, held 

 as it was in a direct line with the plane of the 

 back, upset the bird's balance, and retarded its 

 motions. Seen under these. conditions, the bird 

 reminded me of a somewhat deformed Long-tailed 

 Tit which had lately been sojourning in the 

 purlieus of an abominably smoky city. 



Generally, however, you first exchange 

 greetings with the Dartford Warbler in this way. 

 Drawing near to a ridge of gorse, you suddenly 

 hear the familiar tirr. In fact, you generally hear 

 the note before you sight the performer, for the 



