20 HA WAIIAN BIRDS. 



in summer temporarily visits the lowland belt for nesting pur- 

 poses. 



This upper zone is inhabited scantily, if at all, by forest birds, 

 and then only on its lower edge, which is perhaps occasionally 

 visited by the finch-like forms Chloridops and Pseudonestor, as 

 also by the honey-eating species when the trees of the middle 

 region have ceased flowering. 



It is doubtless neither the altitude nor the cool climate of this 

 upper zone that repels the birds, but the fact that above about 

 6,000 feet the large forest trees rapidly dwindle to scrubby and 

 ■depauperate forms that possesses no attractions for the birds, 

 since they afford neither shelter nor abundant insect or other food. 



Between the upper limits of this zone and 11,000 feet, where 

 Hillebrand fixes the limit of vegetation on Mauna Kea, the veg- 

 etation grows ever scantier and scantier till there is little else but 

 bare lava rocks. 



DISEASES OF HAWAIIAN BIRDS. 



I am not aware that the birds of the Hawaiian Islands are 

 more subject to fatal diseases than those of other lands. Dead 

 birds are, however, found rather frequently in the woods on the 

 island of Hawaii, especially the iiwi and akakani. 



There is no doubt that sudden and marked changes of tem- 

 perature affect Hawaiian birds unfavorably, especially the two 

 species just mentioned and, after heavy and prolonged storms, 

 many individuals of both species are driven into sheltered valleys 

 and even along the sea-shore far from their woodland haunts. 

 Under such circumstances scores of the above named species are 

 picked up dead or dying, and the mortality among other birds is, 

 perhaps, unusually great. 



Every naturalist who has visited the islands has noticed the 

 presence of certain tumors or swellings on the feet of the birds. 

 The tumors are mostly, perhaps, wholly, confined to the woodland 

 birds. The writer has found them upon the feet of the iiwi, aka- 

 kani, omao, elepaio, amakihi, Oreomyza and the genera Hemigna- 

 thus and Heterorhynchus. They have not been present on any of 



