246 Henshaw, Migration of the Pacific Plover. [f^^ 



gestive paper by Austin H. Clarke^ on the probable method by 

 which the bird is guided safely across the Atlantic from Nova 

 Scotia to South America. In the present paper will be presented 

 such facts in regard to the migration of the Pacific Plover (Chara- 

 drhis dominicus fuhus) as the author was able to gather during his 

 stay in the Hawaiian Islands — from ISOl to 1904, together with 

 certain deductions therefrom. 



Isolation of the Hawaiian IshnuLs'. — It may be premised that no 

 other part of the earth's surface is so far distant from continental 

 areas as the Hawaiian Archipelago. The islands are about 2000 

 miles from the coast of California on the east; about the same dis- 

 tance from the Aleutians on the north, and the Marquesas group on 

 the south; and not much further from Japan, reckoning from the 

 outermost of the chain of low islands and reefs which stretches 

 from Hawaii some 700 miles towards the Asiatic coast. It is 

 important to note, however, that, assuming the availability of these 

 islands as stepping stones for birds, there would still be an interval 

 of more than 2000 miles between the most northwestern of the 

 chain and Japan. Hence, if we reject as untenable the theory of a 

 sunken southern continent, of which the Hawaiian Archipelago 

 is the northernmost and now the only visible remains, the original 

 introduction into Hawaii of its mammals, birds, insects and plants 

 presented greater difficulties than were presented to the faima and 

 flora of any other part of the world. 



So remote and isolated have these islands been since their forma- 

 tion, and so few and uncertain Nature's carrying agencies — the 

 birds, the winds, and the ocean currents — that after the islands 

 were thrust up out of the sea ages must have elapsed before they 

 received the parent stocks of the many and diverse forms of plant 

 and animal life peculiar to them. 



That the difficulties of stocking the archipelago with life, great as 

 they must have been, were not insurmountable is proved by the 

 fact that enough waifs found their way to the islands to clothe them 

 with verdure and stock them with animal life. As a result of the 

 competitive struggle which followed upwards of 900 species of 

 plants, numerous insects, including many distinct genera, seven 



1 Auk, 1905, pp. 134-140. 



