Nebraska Ornithologists' Union 55 



The forms peculiar to both the Missouri and Pine ridge re- 

 gions are mostly woodland forms ; those peculiar to the sand hills, 

 with one exception, water birds ; while those peculiar to the plains 

 are birds of the west which find the western end of Nebraska 

 within the limit of their range. The prairie region is distinctly 

 Carolinian, which brings it into contrast with the sand-hill region, 

 which is Upper Sonoran ; but it has no marked physical or floral 

 features, such as have the other regions, to attract forms peculiar 

 to it, and is marked off from the rest of the Carolinian area by 

 negative rather than positive characters. The small number of 

 forms in the Pine ridge region is due to the narrow limit here 

 set to it, practically restricting it to woodland forms. 



VI 



Of course neither resident birds nor migrants are evenly dis- 

 tributed through any given type of environment, and birds are 

 often migrant in environments from which as residents they are 

 excluded. Studies expected to furnish data in regard to such 

 local distribution of forms within our state are now being carried 

 on, but have not progressed far enough to permit of exact state- 

 ments being made. It is hoped that more of our members than 

 are now engaged in such investigations may participate. Most 

 valuable work can be done in any locality by one who will make 

 a careful study of the local bird fauna with respect to occurrence 

 and abundance of different forms in the various local environ- 

 ments and during the different seasons of tlie year. 



