Blackbird and starling damage to white pine, Hanover, Pa., Municipal Watershed, 

 in this area during the winter of 1958-59. (Photo by F. C. Schmid) 



Several million birds roosted 



At the suggestion of the Federal Aviation 

 Agency, the Denver Center is studying the sim- 

 ilarity of sound waves produced by Electra air- 

 craft engines and hoards of singing crickets by 

 which starlings may be attracted to the vicinity of 

 airports. 



A heffer gopher poison. — A better poison than 

 compound 1080 for gopher control, to be used in 

 conjunction with the burrow-builder, apparently 

 has been found, and it is now up to industry to de- 

 termine whether the material can be produced for 

 marketing. This is a chemical supplied to the 

 Denver Center by the Bayer Co. of Leverkusen, 



Germany, coded as DRC-714. The chemical is ac- 

 cepted readily by gophers, and field tests have 

 given better than 90 percent control under favor- 

 able conditions. Moreo\'er, coyotes, bobcats, and 

 domestic cats are 5 to 12 times more resistant to 

 the toxicant than gophers, indicating minimum 

 hazards to animals that may eat the poisoned ro- 

 dents. Of birds so far tested, including poultry 

 and various game species, none have been found as 

 susceptible to DRC-714 as the gophers themselves. 

 Rangelaiul Hprnyimg in pochet-gophc'r eonfrol. — 

 The effectiveness of 2,4— D sprayed on grazed 

 rangeland in gopher control sliowed the following 



41 



