BUREAU OF BIOLOGICAL SURVT:!'. 257 



these lines are chiefly beneficial to man, and increasing their numbers 

 is equivalent to decreasing losses by injurious insects. The problem 

 of attracting such birds has been treated by sections of the United 

 States, and publications on the Northeastern and Northwest ei-n States 

 have been fssued. One relating to the Middle Atlantic States is in 

 press and one for the East Central States has been prepared for 

 publication. A further manuscript in this series, entitled "Attract- 

 ing Rii'ds to Public and Semipublic Reservations" also has been 

 completed. 



THE CARE OF CAGE BIRDS. 



In response to a large and growing correspondence relating to 

 canary birds, a Farmers' Bulletin entitled "Canaries: Their Care 

 and Management" has been issued. In it the history of the domes- 

 tication of this bird is touched upon, and a brief account is given, 

 with illustrations, of the common and fancy varieties, which are dis- 

 tinguished by shape and color. The chief usefulness of the bulletin 

 is in its discussion of practical problems on the care and breeding of 

 these popular cage birds. 



DISEASES OF WILD DUCKS IN UTAH. 



The investigations of the conditions that cause the death of enor- 

 mous numbers of wnld ducks and other waterfowl around Great Salt 

 Lake, Utah, were completed at the close of the field season of 1916. 

 An assistant engaged in this work was stationed iii the marshes in 

 the Bear River delta, at the northern end of Great Salt Lake, from 

 May until October. Experimental work and field observations were 

 carried on there at a temporar}^ field laboratory, and the cause of 

 the main trouble was definitely established as due to chlorides present 

 in the alkaline waters and in the efflorescences on the mud flats. A 

 report, embodying the results of this work has been prepared for 

 publication. 



It was learned in 1915 that a considerable number of waterfowl 

 of various species die in different parts of the country every year 

 from lead poisoning caused by eating the scattered shot that accumu- 

 late at the bottom of the water about shooting blinds. Further 

 investigations into this trouble w^ere made during 1916, and a report 

 thereon completed. 



During the course of these investigations much info.rmation was 

 gathered concerning the breeding, summer and fall movements, and 

 habits of wild ducks in the great marsh areas at the mouth of Bear 

 River, Utah. A study was made of the available natural food supply 

 for waterfowl, and in 1916 a count was made of the breeding ducks 

 of that region. A report covering these observations is in course of 

 preparation. 



BIOLOGICAL INVESTIGATIONS. 



Field investigations of the distribution, abundance, and habits of 

 birds and mammals have been carried on in various parts of the 

 United States, and the work of collating published information on 

 the same subjects has been continued. The information gathered has 

 been of use in the other activities of the bureau, concerned with the 

 administration of the Federal migratory-bird law, the enforcement 



33382°— AGR 1917 17 



