the fate, and distriljution of various pesticides in 

 the animal body, and (2) the isolation and iden- 

 tification of metabolites arising from physiological 

 reactions in the animal, which bring about detoxifi- 

 cation or elimination of these foreign substances. 

 Techniques available and currently employed for 

 biochemical research and pesticide residue deter- 

 minations include thin-film chromatographic 

 apparatus, together with infrared spectroscopy, 

 gas chromatography, ultraviolet and visual spec- 

 troscopy, and paper chromatography. 



The biological laboratory has been equipped 

 with an Auto-technicon and the necessai-y facilities 

 for preparing tissue sections for liistological exam- 

 ination in detection of possible pathological 

 changes resulting from exposure of wildlife to 

 pesticide applications. This line of investigation 

 is expected to prove invaluable in detecting, at an 

 early stage, the development of adverse effects in 

 various species due to pesticide action. 



Surveillance was continued of large operational 

 pesticide applications such as those for the control 

 of spruce budworm in forests and grasshoppers on 

 rangelands. Through the collection of prespray 

 and postspray specimens of wildlife resident in 

 the treated area, the accumulation and retention of 

 pesticides acquired by various species was studied 

 by chemical analyses of tissues. 



Knowledge of the pi'obleni of pesticide residues 

 in nesting waterfowl in the Far North, and the ap- 

 parent transfer of the pesticide to progeny through 

 the egg. was extended by the collection and exami- 

 nation of additional specimens in the summer of 

 1962. 



Studies of the effect of agricultural pest control 

 on wildlife were pursued in the Klamath basin and 

 on the Tule Lake Natural Wildlife Refuge in Cali- 

 fornia. This is a situation where pesticides ap- 

 plied on agricultural lands are transported by 

 irrigation water draining into a "sump irrigation 

 system" where they are apparently concentrated, 

 ultimately, in fish to a level where fish-eating birds 

 acquire acute lethal amounts of poisons. Twenty- 

 eight pelicans and 135 other fish-eating birds, con- 

 sidered pesticide casualties, were found dead on 

 the Refuge in 1962. The solution of pesticide 

 problems of this nature is difhcult since it requires 

 reduction of the toxic concentrations in pooling 

 areas. This can be accomplished only by elimina- 

 tion or greatly reduced use of pesticides in the wa- 

 tershed, which may be inconsistent with the need 

 for protecting croplands from pest damage. 



Captive bald eagle, Petersburg, Alaska. This bird was 

 one of an experimental group used to measure DDT 

 accumulation in eagle's body tissue, an effort on part 

 of the Bureau to learn if the increasing scarcity of the 

 bird designated as the National Emblem of the United 

 States is related to pesticidal contamination of eagle's 

 food. (Photo by Paul A. Stewart) 



A field study having the positive objective of 

 evaluating a grasshopper-control insecticide hav- 

 ing minimum hazard to wildlife was initiated at 

 the Ix)Stwood National "Wildlife Refuge in North 

 Dakota, in cooperation with the Plant Pest Con- 

 trol Division of the Agricultural Research Serv- 

 ice and the ITnion Carbide Corporation. Two 

 plots of 2,000 acres each were selected as an experi- 

 mental and a control area. The experimental plot 

 was sprayed by airci-aft in July 1962 at the rate of 

 1 pound of the insecticide Sevin per acre. Care- 

 ful surveillance of the two areas through October 

 1962 indicated little, if any, immediate hai-m to 

 wildlife. Continued observation of these plots 

 will be maintained in 1963 and, if indicated, in 

 196-t to detennine possible chronic efl'ects. This 

 field investigation is adequately supported by 

 chemical analy.ses of environmental and wildlife 

 sfjecimens collected at specified intervals. 



Accomplishments in the chemical and biochemi- 

 cal area of research resulted in an improved ana- 



47 



