THE ^^POWDER-DOWN" OF THE HERON. 287 



thus for fully half-an-hour, in the warm sunshine, without 

 a movement except the occasional turning of its head, as 

 it surveyed the neighbourhood. About noon a pony which, 

 as I thought, had been watching the Herons for some time 

 ran across the field and drove them away. Before they 

 went I noticed that their bills were still bluish in colour. 



October 1st — mild, sunny weather. Six Herons in 

 the sedge. Two came into the meadow and for a while 

 preened desultorily. The bill of each bird was yellowish 

 in colour. One bird stood in the usual attitude, without 

 shaking out its plumage, and at intervals smoothed 

 feathers here and there without having recourse to the 

 powder-downs. Its bill remained yellow. The second 

 bird began by shaking out its plumage to a marked degree 

 of fulness. Then it pressed its bill into the region of the 

 right breast powder-down and rubbed the bill up and 

 down gently. After preening a few feathers on the breast 

 it devoted its attention to the right wing, where it preened 

 the coverts, especially the lower, and drew its bill over 

 and among the remiges of the half -opened wing. The 

 left wing was preened less carefully. It was sunny then, 

 and at intervals the Heron held out its wings horizontally, 

 as Cormorants do. The wings trembled visibly at these 

 times, and the bird soon let them fall, as if tired. When 

 the bill was lifted from the powder-down the lower 

 mandible alone was of a bluish colour and, in the case of 

 the under coverts which were turned towards me, the 

 bill was introduced below each feather at the outer 

 border and drawn to the tip, so that the under-surface 

 of the bill came into contact with the under-surface of 

 each feather. This bird shook its bill vigorously side wise 

 at times as if to get rid of something. 



October 4th — a calm, sunny day. A Heron which had 

 been watching for food in the estuary stepped out of the 

 water and walked slowly some way over the sands. There 

 it shook itself so as to fluff out the plumage. At that 

 time the bill had a shining appearance, and was of a straw- 

 yellow colour. The Heron pressed its bill into the region 



