A Wild Duck. 63 



to guide the incomers. How they do it is uncertain ; 

 it is probably in some such way as the night-hawk 

 makes his curious booming sound, — not by means 

 of his open mouth, as is generally supposed, but by 

 slightly turning the wing quills so that the air sets 

 them vibrating. One can test this, if he will, by 

 blowing on any stiiJ feather. 



On stormy days the birds, instead of resting on the 

 shoals, light near some lonely part of the beach and, 

 after watching carefully for an hour or two, to be 

 sure that no danger is near, swim ashore and collect 

 in great bunches in some sheltered spot under a 

 hank. It is indeed a tempting sight to see per- 

 haps a hundred of the splendid birds gathered close 

 together on the shore, the greater part with heads 

 tucked under their wings, fast asleep ; but if you are 

 to surjarise them, you must turn snake and crawl, 

 and learn patience. Scattered along the beach on 

 either side are single birds or small bunches evi- 

 dently acting as sentinels. The crows and gulls arc 

 flying continually along the tide line after food ; and 

 invariably as they pass over one of these bunches of 

 ducks they rise in the air to look around over all 

 the bank. You must be well hidden to escape those 

 bright eyes. The ducks understand crow and gull 

 talk perfectly, and trust largely to these friendly sen- 

 tinels. The gulls scream and the crows caw all day 



