94 FLORIDA BIRD-LIFE 



Pelican Island is unfortunately so low that a severe 

 "norther" raises the water sufficiently to flood all but the 

 sand-bar at its eastern end. Only those birds which build 

 upon the sands are secure from the waves. In April, 1905, 

 all the occupied nests were on the higher, eastern portion of 

 the island and anyone visiting the island at this season 

 might have been led to credit the birds with sufficient intelli- 

 gence to select a nesting site above high-water mark. Where- 

 as, in truth, the earlier homes of many of these same birds, 

 built on low ground, had been inundated, and their eggs 

 washed from the nests, were still scattered about the island, 

 as may be seen in several of the accompanying photographs. 

 Apparently, then, there is no conscious selection evolved by 

 experience. Year after year, birds nest on low ground and 

 suffer the consequences, while the higher ground colony is 

 established by the elimination, through disaster, of the birds 

 which do not resort to it. 



Lost eggs may be and doubtless usually are replaced 

 and it is rather through its effects on the young birds that 

 the ground nesting site produces so high a mortality. I have 

 never visited a colony of nesting birds containing anything 

 like the number of dead young commonly to be seen on Peli- 

 can Island. 



Under normal conditions a Pelican born in a tree-nest 

 does not leave the tree in which its home is placed until it 

 makes its first attempt at flight. When born on the ground 

 it leaves its nest as soon as it can walk. The tree-born bird 

 has therefore not only a cooler, better ventilated, cleaner 

 home, but he is not brought into competition with his fellows 

 before he is strong enough to care for himself. The struggle 

 for food is severe and while the parents make every effort to 

 feed their young, they are sometimes deceived and the young 

 themselves are at times robbed of their food before they 

 have an opportunity to swallow it. Furthermore, the young 

 are ten weeks old before they can fly and during at least the 

 first half of this period the flooding of that portion of the 

 island on which they were born would result fatally. 



