270 BULLETIN 142, UNITED STATES NATIONAL MUSEUM 



in the air in a direct rapid flight, to disappear hehind a rock on the opposite 

 beach of a lake, etc. From quite another direction she soon appeared again 

 just before my feet. 



If I finally retired still farther away from the young ones and for a while 

 kept myself hidden in the field, she would fly slowly, sometimes quite low, over 

 the earth to the spot where the young still were lying motionless and mute, 

 with their bodies pressed flat against the earth and their neck and head 

 stretched out. When at last the female considers the danger to be over, she, 

 flying or running close to the chicks, produces a short chirping song, at the 

 tones of which all four young ones suddenly get up and begin to run about. 

 Only in this case the sanderling produces its highly peculiar " sanderling song," 

 which is very similar to the song of Sylvia curruca. As long as the young kept 

 lying quiet on the ground in the before-mentioned attitude they were extremely 

 difficult to find, if I had not from my ambush by aid of my field glass exactly 

 marked down the spot where they last appeared. The young ones do not seek 

 any real cover, as in hollows in the ground, under plants, behind stones, or 

 similar natural hiding places. When I had found a single young one, which 

 while I kept it in my hands began to chirp, it generally happened that the three 

 other young, which had till then kept quiet, suddenly rose and, with the wings 

 raised, uttered a quite fine mouselike squeaking and hastily rushed away, 

 while the old female, as if paralyzed, lay down before my feet, still squeaking 

 exactly like the chicks. 



Within 12 to 14 days the young ones are full grown and able to fly. Strange 

 to say, the brood of the sanderling seems to suffer very little from hostile 

 persecution, a fact which may be due to the accomplished vigilance and prudent 

 behaviour of the old female and the young as well as the extremely suitably 

 coloured clothing of these. I wonder that these defenceless small beings can 

 avoid the Polar fox, which in this season more frequently than usual visits 

 the domain of the waders, and which, as well known, has an excellent sense 

 of smell. 



Plumages. — The nestling sanderling is thus described in Witherby's 

 Handbook (1920) : 



Forehead buff with a median black line from base of upper mandible to 

 crown ; nape buff, down with dusky bases ; rest of upper parts variegated 

 light buff, warm buff and black and more or less spangled white ; lores buff, 

 two black lines across lores toward eye ; under parts white, cheeks, chin and 

 throat suffused light buff. 



Mr. Manniche (1910) gives a colored plate showing four ages of 

 downy young sanderlings, which the above description fits. A 

 nestling 7 days old shows the remiges about one-third grown, while 

 the body is still all downy. Another nearly fully grown only 11 

 days old is still downy on the head, neck, rump, and crissum, but 

 is nearly fully feathered on the mantle and wings, partly feathered 

 on the under parts and the wings extend beyond the stump of a tail ; 

 it must be close to the flight stage. Such is the rapid development 

 of these little Arctic birds that Mr. Manniche (1910) says that they 

 can fly when 14 days old. 



In fresh juvenal plumage in the Arctic the feathers of the crown, 

 mantle, wing coverts, scapulars, and tertials are blackish brown, 



