Anthracnose damage to milo is sometimes incor- 

 rectly diagnosed as blackbird damage. Note how 

 closely the blasting due to anthracnose on the upper 

 part of this head of milo resembles bird damage. 

 (Photo by J.W. Hardy, Virginia Cooperative Wildlife 

 Research Unit.) 



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Some varieties of grain crops are more resistant to 

 bird damage than others. Here the two heads on the 

 left are blackbird resistant; those on the right are 

 badly damaged. 

 (Photo by J.W. Hardy, Virginia Cooperative Wildlife 

 Research Unit.) 



planes, trains, and sirens. A carryall truck 

 has been equipped with recording and ampli- 

 fying devices for use in studying the effects 

 of sounds on birds in the field. Also, a con- 

 tract was entered into with the Stanford 

 Research Institute to explore the effects 

 of different frequencies and intensities of 

 sounds on birds. Previous research has 

 shown that carbide exploders, the sound of 

 .22 caliber rifle fire, and other noisemakers 

 and scare devices are effective under some 

 conditions. 



Repellents and toxicants .-- At the Denver 

 Wildlife Research Center 421 coded chem- 

 icals were received from 10 cooperating 

 chemical companies in a program to se- 

 lect and test compounds of potential use 

 in preventing animal damage to forest and 

 range plants. The chemicals were used in 

 bioassay studies to determine their toxic 

 and repellent characteristics, and the 132 



compounds which exhibited desirable char- 

 acteristics were given phytotolerance tests 

 to determine their effects on seed germina- 

 tion and seedlings. They were also subjected 

 to more advanced tests to determine plant 

 translocation or systemic characteristics. 

 Nearly 11,000 small mammals were used As 

 test animals. Of five promising chemicals 

 which emerged from the screening program 

 in 1961 and which were sent to the Olympia, 

 Washington, substation for field-testing, two 

 are highly repellent to small mammals while 

 exhibiting low toxicity, one is a cumulative 

 toxic agent, and the other two are systemic 

 compounds having both repellent and toxic 

 characteristics. 



Limited tests of several lethal chen-iicals 

 were made at cattle feed lots and at black- 

 bird or starling roosts in holly groves and 

 other sites, but none can be recommended 

 for operational use at this time. 



25 



