HA WAIIA N BIRDS. 17 



island. Nevertheless, the main geographical relations of the 

 fauna and the flora appear to be much the same upon all the 

 islands, though each island, no doubt, presents peculiarities due 

 to local conditions. 



Present available data are all too insufficient for an accurate 

 definition of the ornithological life zones of the islands. Indeed, 

 owing to the general climatal sameness and the similarity of the 

 forest belts and the consequent wide range of the birds, it may 

 be doubted if such life zones can ever be defined with the pre- 

 cision attained elsewhere. A consideration of the subject, how- 

 ever, discloses some interesting facts which may here be briefly 

 set forth. 



Lowland Zone. — Hillebrand (Flora of the Hawaiian Islands) 

 found it possible to diflferentiate more or less sharply four zones 

 according to the plant, life. Of these, three only have much in- 

 terest for the ornithologist. 



His first or lowland zone has but slight interest in the present 

 connection. It is the open country, grass-covered, with scat- 

 tered clumps of trees (chiefly ohia) and extending to a variable 

 but always slight elevation above the sea. The rainfall in this 

 belt is considerable, probably nowhere falling below loo inches 

 per annum, while the average temperature ranges between 70 

 and 80 degrees Farenheit. 



Except casually and in small numbers, it is not probable that 

 this lower belt was ever occupied by any of the passerine spe- 

 cies. It probably always was, as it is to-day (save for the intro- 

 duced mynah and rice birds) almost an avian desert, uninhab- 

 ited because no passerine birds adapted, or capable of adapting 

 themselves to such conditions ever chanced to find their way to 

 the islands. It may be remarked in passing that the short- 

 eared owl abounds in this zone, but extends its range into the 

 next one. 



This belt of comparatively open country offers excellent op- 

 portunities for the introduction from America of ground-loving 

 species friendly to agricultural interests, although it cannot be 

 overlooked that all ground-building species must now contend 

 for existence against a formidable foe in the shape of the mon- 



