A.NTVL\L CONTROL METHODS 



The need for more effective and selective meas- 

 ures for controlling birds and mammals injurious 

 to forests, crops, rangelands, and stored goods, 

 and inimical to human health, becomes more acute 

 as competition between man and wild animals 

 increases. Many approaches to the new control of 

 such animals are being explored by the Bureau, 

 including manipulation of habitat, cultural pnic- 

 tices, chemical repellents and scaring devices, 

 drugs and lethal substances, traps, sonic and elec- 

 trical installations, radiation, reproduction inhibi- 

 tors, and biological agents. 



&uJh controlled hy predator^. — On two small 

 islands off the Massachusetts coast, raccoons and 

 foxes achieved 90 percent control of the gull popu- 

 lations present. Two individuals of each predator 

 were liberated on each island before the 1964 

 nesting season, and gull eggs and chicks became 

 the main source of food after nesting began, since 

 neither crops nor poultry are produced on the 

 islands. Xo other predators occur. Biological 

 control of gulls imder these circumstances is both 

 practical and economical, but many nesting colo- 

 nies are closer to man's habitation, requiring that 

 release of predaceous mammals be tempered by 

 economic or other biological consideration. This 

 method, therefore, while seemingly effective, is 

 limited in application. 



Xew avicide for starlings and blackbirds. — Con- 

 tinued progress was made by the Denver Center in 

 196i in developing DRC-1339 as an avicide for 

 starlings and blackbirds, and this new chemical 

 has emerged as one of the major developments in 

 bird-damage control during r^ent years. It is 

 many times more toxic to starlings and blackbirds 



:.al personnel 

 ;iiandte ^ 



than to mammals, and the margin of safety is so 

 wide that accidental k; _ .mals in any 



pix)perly conducted bin: .. ; . ,.c»gram is vir- 

 tually nonexistent. Funhermore. the several 

 spec-ies of hawks that have been tested are so 

 resistant to DRC-1339 that there '- ' ■ -'-'reseeable 

 danger of accidental killing - hey eat 



poisoned starlings: y of second- 



ary poisoning seem^ .... ..V. .c-<..ti by growing 



evidence that the chemical is rapidly metabolized 

 ainated by r ,ry victim. 



^.,.^.;trarion of ti.i .... imd for experimental 

 use at cattle. f>oultry. and hnor feedlors was ap- 

 proved by the Pesticide Rej ' - : f 

 the Department of Agricu'.' . ■.i..i-.i> ra- 

 tions were held to acquaint 



iracteristicsof i; 

 i-jj. ii^.d use. Large-scaic ..^jvi lesting wa^ .... ad- 

 taken during the winter of 1964—65. Initial re- 

 ports on the trials indicate that excellent results 

 were obtained. 



flelp for urban starling victims. — In 1963. biol- 

 ogists of the Denver Center demonstrated that 

 roosting bir-^- i ] be mo\"ed. at least temporar- 

 ily, by thr _ _hTed sparklers into the trees. 

 In 1964. a r! _' of starling distress calls 



was convene. ... ■■ .-nanereial-" '- -^ ords and 

 distributed to 31 residents of :. : area in 



Denver where 5,00<) starlings had formerly roosted 

 nightly from summer to fall. Householders were 

 instructed to play the records on ponable players 

 at their homes when the birds started to roost in 

 the evening. Instructions were followed the first 

 4 nights by 13. 9. S. and 6 householders. Diminish- 

 ing numbers of birds attempted to roost each eve- 



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