268 BULLETIN 113, UNITED STATES NATIONAL MUSEUM. 



became tired and turned toward shore the parent met it and forced it to turn 

 back. This maneuver was repeated over a dozen times, until the young bird was 

 forced off to sea out of sight. "This was one of the most striking instances of , 

 bird sagacity I met with in the north. 



Plumages. — Doctor Nelson (1887) describes the downy young as 

 follows : 



The downy young of this species appear to be distinguishable from the 

 young of all other species. The color above is a grayish buff profusely blotched 

 with black. The black of the chin and throat extends somewhat to the upper 

 portion of the breast. The breast is pure white, shading into a very dark 

 gray on the belly and sides. There is considerable difference in individual 

 specimens, some being of a light buff above. As compared with the downy 

 young of paradisaea from Labrador, these birds are darker above, buff instead 

 of a light fulvous, and with more black blotching. The black of the under parts 

 in paradisaea is limited to the chin and throat, while the belly is of a much 

 lighter color. 



He says further: 



The young in any stage may be readily distinguished from the young of 

 paradisaea. by the deeply cleft toe-web, whereas the web of the latter is nearly 

 full. 



August birds, in fresh juvenal plumage, have the crown "fawn 

 color " or " wood brown " mottled with blackish, more thickly pos- 

 teriorly ; the sides of the neck and chest are washed with paler shades 

 of the same; the feathers of the back, scapulars, and lesser wing- 

 coverts are dark " sepia," broadly^ edged with " cinnamon buff," 

 which is most conspicuous and brightest on the larger scapulars; 

 the secondaries are broadly tipped with white, making a con- 

 spicuous wing band; the rump is ashy, not white, as in the Arctic 

 tern; the tail feathers are broadly tipped with "cinnamon buff" 

 beyond a subterminal dusky area ; the under parts are white. These 

 colors become paler with age and probably the buff edgings fade 

 out to white or wear away during the fall. 



Unfortunately we have no material for study in our collections 

 which illustrates anything but the juvenal and the fully adult breed- 

 ing plumages, so we can only guess at the subsequent molts and 

 plumages. No birds in immature spring plumage have ever been 

 taken on the breeding grounds, which shows that the young birds 

 do not breed during the first spring or that the full plumage is 

 acquired by that time ; probably the latter is the case. 



Food. — There seems to be no data on the food or feeding habits of 

 the Aleutian tern, but probably it does not differ materially in this 

 respect from the Arctic tern, with which it seems to be intimately 

 associated. 



Behavior. — ^Regarding the appearance of the Aleutian tern in life, 

 Mr. Hersey says that it can be distinguished from the Arctic tern by 

 its darker color, the under parts, including the wing linings, appear- 



