LIFE HISTORIES OF NORTH AMERICAN WILD FOWL 89 



The adult birds in spring did not seem to be quite so particular; in tbem I 

 found almost all the common forms of marine invertebrates, and sometimes 

 even a few fish {Liparis, and the young of Coitus scorpius). 



Mr. Andrew Halkett (1905) found the followino; material in the 



o-izzards of some 20 eiders : 



Numerous shells of Acmaca tcstvdhnilift, numerous fragments of valves of 

 Tonicella marmorata, a few shells of Margarita cinerea, a number of shells of 

 other small gastropods, a few opercula of a gastropod, egg capsules of a gastro- 

 pod, numerous valves of Crenella, fragments of valves of various small and 

 medium sized lamellibranchs, various parts of the shells of Hyas and other 

 trustaceans, a few pieces of the arms of an ophiurian, a few bones of a very 

 small teleost. fragments of alga, numerous small stones. 



Behavior. — The fliLdit of the northern eider is apparently slow, 

 hea\w, and labored, but in reality it is much stronger and swifter 

 than it appears and exceedinii-ly straight and direct. Its heavj'- head 

 is held low, with the Ijill pointing slightly downward, a character- 

 istic and diagnostic attitude. Eiders usually fly in small flocks, in 

 Indian file, close to the water, often following the indentations of 

 tlie shore line, but very seldom flying over the land. In rough 

 v.eather a flock of eiders is apt to follow the trough of the sea and 

 is often lost to sight between the waves. I have seen one, when shot 

 at and perhaps wounded, dive out of the air into the water and not 

 show itself again. It is an expert at diving and hiding below the 

 surface; if there is only the slightest ripple on the water it can con- 

 ceal itself and swim away with only a portion of its bill protruding 

 and almost invisible. 



As stated above, eiders are capable of diving to depths of 8 or 10 

 fathoms if necessary. In diving the wings are partially opened 

 and used to a limited extent in swimming under water, but the Avings 

 are not wholly spread ; progress seems to be made mainly by the use 

 of the feet, and there is nothing like the full subaqueous flight prac- 

 ticed by some of the Alcidae. Mr. Millais (1913) relates the follow- 

 ing interesting incident: 



Personally I have the gravest doubts of the truth of the statement made by 

 many writers that the eider and other sea ducks " hold on " to the seaweed 

 at the bottom of the ocean rather than allow themselves to come to the surface 

 and he shot. One morning in February, ISGG, I pursued an old mule eider, which 

 I had winged from a flock, into some shallows off the island of Reisa Little, 

 in the Orkneys. The white back of the bird could be plainly seen under water 

 entering some dark weeds amongst small rocks near the shore. Presently it 

 disappeared in the tangle, and as the bird did not again come to the surface 

 I leaned over the side of the boat and made search for it. I had seen it enter 

 a comparatively small area of dark ground round which there were sand 

 spaces, so I concluded it must be hidden amongst the fronds, and after a 

 short search I saw the white back gleaming beside a small rock, the head and 

 neck being concealed under the seaweed. It occiu'red to me that it would J)(! 

 interesting to see whether the bird would voluntarily leave this po.sition or 



