Care of Young, 141 



of labor shall be just ; but a careful watching of the 

 flocks, shows that there is a regular system for 

 change of sentinels. 



Major Stansbury* gives us an account of the 

 young Pelicans at Utah Lake being watched over 

 by one old Pelican, while the others v/ere engaged 

 in fishing. Each sentinel or guard, was regularly 

 relieved, in turn, by another taking her place. 

 Here the community system was introduced among 

 these birds for the purpose of caring for their young. 

 But as he found one old Pelican, though blind and 

 unable to fish for himself, still sleek and apparently 

 well cared for by his fellows, it is fair to infer that 

 the community system, among these birds, secures 

 to some extent, mutual aid among adults. 



I have myself seen something of this communi- 

 ty of action, in the care of young, among the Arctic 

 Tern on the coast of Greenland. One little grassy 

 island, that I had the opportunity of watching for 

 eight days, was entirely occupied by Tern. They 

 made no nests, but deposited their eggs among the 

 grass. The island fairly swarmed with their young, 

 from those just out of the shell to those of full size, 

 ready to fly. The old birds made common cause 

 against any intruder ; and it was settled by obser- 

 vation, that they did not always feed their own 

 young. Three different adults were seen feeding 

 the same young bird that had been placed upon a 

 rock by himself. All the young seemed to be well 

 cared for ; but how the favors of the old birds were 



* Ex. Doc, No. 3 Senate, Sp. Sess. 1851. 



