v A Chapter on Wagtails 123 



her leading her young brood across the water, jerking 

 her tail so that its white is constantly visible to 

 them, and at the same time calling them to follow 

 the standard they see thus held out for them. I have 

 seen an old Eeed Bunting sitting on a rail and calling 

 his young about him, while at every twitch of his 

 tail it was just so much expanded as to show the 

 white, and with the white his position. I believe, 

 then, that in these and some other instances the 

 nervous trick has a secondary use ; it is not only a 

 sign of satisfaction, but also a signal, and the white 

 is a recognition mark, as Mr. Wallace has called it. 



If I were to go into the whole question of recog- 

 nition marks in birds, I should be wandering beyond 

 the limits of this chapter. Let me finish it, before I 

 am tempted to stray further, by asking those who 

 find a pleasure in Wagtails to observe their tails at 

 leisure, and to let me know if they find reason to 

 doubt that their motion is a nervous habit, arising in 

 the first instance from mental satisfaction, but capable 

 of being turned to good account as signals to their 

 families and friends. 



white. And it is worth noting that birds which have both are 

 apt to choose conspicuous places for perching, as the Wheatear, 

 Stonechat, Whinchat, Bullfinch, the Shrikes, and the Buntings. 



