Auk 
206 HENSHAW, American Birds in Hawatt. ily. 
venture so far for a few months’ sojourn upon the sunny Pacific 
Isles. However favorable the conditions, the trip must be full of 
hardship and danger, especially to the old, the young, and the 
sick, and doubtless thousands occasionally perish on the way, 
particularly in stormy weather. Why leave the safe mainland for 
islands twenty-five hundred miles away? In this connection it is 
of interest to note that by no means all the Kolea and Ake- 
keke and Ulili (Zotanus incanus) leave the Islands in spring. 
Thousands of the two former species remain all summer in the 
uplands and the Ulili is by no means uncommon along shore. 
I have examined numbers of such loiterers and find them, with- 
out exception, to be young birds, apparently birds of the year 
probably too immature to feel the mating impulse. 
Adult birds on the contrary, shot in April, which already have 
assumed the nearly complete nuptial dress, reveal clearly upon 
dissection the effect of the all controlling passion, and I am not 
sure that in some cases they are not already paired before leaving 
the Island. Some wounded adult birds must preforce remain 
behind while their fellows, in obedience to the homing instinct 
—the strongest impulse that stirs the avian breast— seek the 
Alaskan tundras. Why do not such island prisoners breed? 
Food would seem to be abundant here in summer as in winter, 
and so far as temperature is concerned, the flanks of the lofty 
Hawaiian mountains offer any temperature from that of perpetual 
summer to everlasting winter. 
