1916] Dice: Land Vertebrates of Southeastern Washington 327 



COMPARISON WITH OTHER SCHEMES OF 

 ECOLOGICAL DISTRIBUTION 



The vertebrate associations as here recognized cannot be compared 

 directly with other schemes of vertebrate associations, because the 

 local distribution of no other region of similar climatic conditions has 

 been studied by the associational method. However, a comparison can 

 be made with several schemes of ecologic distribution used in other 

 regions. 



Weaver (1914) has studied the plant associations found in Whit- 

 man County, Washington, and the Thatuna Hills of adjacent Idaho, 

 where the vegetational features are somewhat similar to those of the 

 region we are studying. He recognizes the following plant associa- 

 tions: bunchgrass-rimrock association, prairie association, yellow pine 

 association, fir-tamrack association, and cedar association. The bunch- 

 grass-rimrock association corresponds to the rocky-slope association 

 of the prairie area as used in this paper. The prairie association is 

 the same as our bunchgrass association. 



Gates (1911, pp. 9-11) has included flycatchers and swallows in 

 the aquatic association because they capture insects in the air over 

 the water. However, such forms cannot be considered to be aquatic in 

 any sense of the term and we have therefore placed them in the aerial 

 association. 



Shelf ord (1913, p. 262) in the Chicago area has recognized a dis- 

 tinct animal community in the narrow border of shrubs and weeds 

 occurring between the prairie and the forest proper. This forest- 

 margin community is very distinct in many regions, but it has been 

 thought undesirable to recognize it as an association between the willow 

 associations and the bunchgrass or sagebrush associations of south- 

 eastern Washington. The willow habitat in the region is usually nar- 

 row and is often rather open. It resembles in these respects the forest 

 margin rather than a true forest habitat. In the Blue Mountains the 

 yellow pine forests pass over into the prairie usually without any indi- 

 cation of a marginal habitat. The other conifer forests of the area are 

 sometimes bordered by an extensive growth of brush and this has been 

 called the buckbrush habitat. 



Kennedy (1914) in a study of the birds of the Yakima Valley, 

 Washington, gives separate lists of the birds of the sagebrush and of 

 those found along the streams. No attempt is made to distinguish 



