Nutria bed in marsh vegetation in Louisiana (left). These large rodents injure field crops and forest plantations 

 and tunnel into ditch banks, causing cav^ins. An experimental control technique consists in baiting with 

 toxin-treated carrots on floating platforms (right), placed at intervals of about 1 mile along shorelines and 

 ditches. Zinc phosphide, one of the toxic compounds being tested, has a minimum hazard to other wildlife. 

 (Photos by Van T. Harris, left; James Evans, right) 



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Gulls, omnivorous in fixxl habit-s, depended almo.st entirel.v on natural foods a centur.v ago. Increasing human popu- 

 lations have resulted in vast quantities of waste materials, inducing change in feeding habits, especially in the 

 herring guU. With increased food supplies, this species has increased greatly in number, becoming a hazard 

 around airfields and a pest along waterfront areas of towns and cities. The Bureau is making an effort to 

 develop safe and effective means of control. (Photo by Rex G. Schmidt) 



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