OKLAHOMA ACADEMY OF SCIENCE 45 



in this zone but probably is not restric ted to the Upper Austral. 

 Most of the hard wood trees are absent but certain species of 

 oak are found where soil and moisture conditions are favorable. 



The rest of Oklahoma is within the Lower Austral zone. This 

 is primarily the land of cotton. The pecan (Hicoria pecan), the 

 loblolly pine (Pinus tacdca), the magnolia (Species?) the live oak 

 (Qiiercus virgiiiiana) and several other species of oak, and the 

 cypress in the swamps are indicators in the morq moist area of 

 this zone. In the less humid area (west of the 98° meridian) 

 there is an intermingling of indicators of the Upper Sonoran and 

 Lower Austral with some Lower Sonoran indicators, such as the 

 mesquite and road runner (No. 385) in the southern part. 



Isotherm 26°., which divides Upper and Lower Austral 

 zones, has probalily never been determined very accurately in Okla- 

 homa. Thru western Oklahoma these zones merge into each 

 other so gradual!}^ and the isotherm is so variable annually that 

 there probably is a belt to limit this isotherm, within which one 

 might expect an intermingling of indicators. In like manner the 

 division between the Sonoran and Austral areas is much less 

 definite. When these limits are more or less accurately estab- 

 lished they will be very irregular lines and probably will vary 

 considerably from their location as indicated by Merriam. 



ECONOMIC RELATIONSHIP OF BIRDS, INSECTS, 

 AND FISHES IN OKLAHOMA 



C. E. Sanborn, 1917. 

 (Abstract) 



The annual loss as occsioned by insects in the United States 

 is computed at $1,272,000,000.00, one forty-eighth of which is over 

 $20,000,000.00 per yer. 



In the consideration of the birds from the standpoint of food 

 habits, I will place them in three groups, — the aquatic, the non- 

 aquatic m.igrants, and the residents. There are no aquatic birds 

 that are of very much economical importance in this state from 

 the standpoint of insect control. They arrive too late in the fall 

 and leave too early in the spring. 



Migratory birds other than the aquatic birds are of more 

 beneficial importance economically from the standpoint of insect 

 control than all other (excepting perhaps the meadow lark) com- 

 bined. Specific mention of these include the blue bird, the wren, 



