THE DUNLIN 465 



at the next, as though caught from behind by a sudden gust of wind, 

 the cloud of birds buckles up as it were, and becomes a tall moun- 

 tainous mass. The changes occur gently or suddenly as in a wreathing 

 cloud of smoke, which in the distance the dunlin flocks resemble. 



Mr. J. M. Dewar, in an interesting article dealing with the feeding- 

 habits of the dunlin, 1 states that it hunts by sight or touch, or by a 

 combination of both. Where large numbers of small molluscs are 

 scattered over sand and mud, the dunlin runs swiftly to and fro, 

 watchful for the slightest movement made by the shells. By selecting 

 only those that move, it guards itself against swallowing empty shells, 

 and those in which the molluscs are dead or dying. Where the tiny 

 pits in wet sand, indicating the burrowings of thin-skinned crustaceans, 

 occur, the dunlin looks for the marks, and having decided on a likely 

 place, it probes the sand in a certain direction, which, it has learned 

 by experience, leads to its quarry. In like manner it searches for 

 worm-castings. As the extrusion of the casts occurs periodically, and 

 the worms are then very near the surface, Mr. Dewar believes that 

 the dunlins are on the look-out for "castings at the moment of 

 extrusion, when they are able to capture worms which may be out of 

 reach at other times." On mud where numerous crustaceans and 

 worms have retired far into their burrows, the dunlin run about and 

 examine various burrows, tapping gently round the entrance of some 

 of them. As worms are beyond reach, these selected burrows are 

 probably those of certain crustaceans which "have the terminal 

 portions of their burrows recurved ; in some cases the blind ends are 

 within a quarter of an inch of the surface and close to the entrance," 

 for, after tapping, the dunlin " suddenly plunges its bill very obliquely 

 into the mud, and reaches upwards with the point." The bill may be 

 seen to " travel in a curved course towards the entrance of the burrow 

 as if following the crustacean, the capture of which may be signalled 

 at any moment by the snapping of the mandibles." 



Where no surface indications occur to guide the dunlin as to the 



1 Zoologist, 1901, pp. 1-14. 



