

3S£* 



The effects of pesticides on game and aquatic birds are being determined under controlled conditions at Bureau 

 research centers. Pheasants, quails, ducks, geese, sharptail grouse, gulls, and pelicans are some of the birds studied 

 in 1963. (Photos by L. G. Kesteloo, left ; James E. Peterson, right) 



been found low in direct toxicity. Sharptails have 

 survived acute doses of Sevin up to 1,500 mg/kg, 

 and prairie chickens have survived up to 1,800 

 mg/kg. 



DDT residues in mule deer. — The accumulation 

 and elimination rate of DDT residues or metabo- 

 lites was determined at the Denver Center in a 2- 

 year mule deer buck by analyzing subcutaneous 

 fat from the rump before, during, and after ex- 

 posure to DDT placed in the feed at a rate of 10 

 mg/kg/day for 10 consecutive days. Feeding of 

 DDT began on September 27 and ended on Novem- 

 ber 8, 1963. Fat samples ranging in amount, from 

 2.8 to 5.4 grams were obtained at each biopsy. 



Analysis of fat samples taken 3 days before the 

 beginning of the test showed less than 0.5 p. p.m. 

 for the aggregate of insecticide residues. Seven 

 days after ingestion, residue levels were 27 p.p.m. 

 for DDT and 1.6 p.p.m. for TDE. Sixteen days 

 after conclusion of the 10-day test, residue values 

 had increased to 58 p.p.m. and 7.3 p.p.m. respec- 

 tively, and by November 8, about 1 month after 

 the last DDT ingestion, they were 0.6 p.p.m. and 

 2.4 p.p.m., respectively, in the fat samples. On 

 the same date, various organs showed traces of 

 DDE, up to 12 p.p.m. of DDT, up to 1.6 p.p.m. of 

 TDE, and up to 0.84 p.p.m of DDMU. 



Toxicity of organophosphate insecticides to 

 ?)iallards. — In 1963, the Denver Center, in coopera- 

 tion with the University of California and the 

 Kern Mosquito Abatement District, began research 

 on the effects on mallards of Guthion, Baytex, 

 parathion, SD-7438, and Sumithion, at 25 p.p.m. 

 of the diet. 



Eight ducks in each of six pens were offered food 

 contaminated with one of the five insecticides. 

 One pen served as a control. From the first week, 

 birds on Baytex and parathion diets ate much less 

 than those on Guthion, Sumithion, and SD-7438. 

 The average consumption in grams per bird per 

 day was: Control, 74; Guthion, 77; parathion, 50; 

 Baytex, 38 ; SD-7438, 78 ; and Sumithion, 72. 



Birds on Baytex and parathion diets ate an aver- 

 age of 140 grams of clean food per bird per day 

 during the first week, indicating that they were 

 influenced more by the repellent quality of the 

 insecticides than by intoxication. Later, control 

 birds consumed 46 grams of clean food per bird 

 per day and 15 grams per bird per day of the Bay- 

 tex diet, indicating that mallards are repelled by 

 even small amounts of this insecticide. Individual 

 birds continuously on Baytex diets died after 28, 

 32, and 35 days, and those on parathion diets died 

 after 28, 29, and 41 days. 



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