BUREAU OF BIOLOGICAL SURVEY. 349 



pheasant farm there, and to collect specimens. The trip was mod- 

 erately successful, but weather conditions Avere not propitious for the 

 usual large flights. 



In furtherance of a cooperative project with the Chemical War- 

 fare Service. Edgewood Arsenal. Md., was visited for the purpose of 

 planning equipment and procedure for an investigation of the pos- 

 sible usefulness of toxic gases in the control of injurious birds. 



An illustrated lecture on " The value of birds to agriculture " sup- 

 plied by the bureau to the States Relations Service at an earlier date 

 for distribution was in good demand. During the latter half of the 

 year i-l sets of slides were sent out. each accompanied by a copy of 

 the lecture, several of them on circuits where they were in daily use 

 for a month or more. 



EXAMINATION OF STOMACHS OF BIRDS. 



Work was continued on the Enixlish sparrow, the contents of about 

 800 stomachs being analyzed. Examinations of various groups of 

 shorebirds were kept up to date, a considerable accunnilation of ma- 

 terial representing the various species of plovers was disposed of, 

 and about 700 pellets of owls were examined. 



Numerous special examinations of bird stomachs for correspond- 

 ents were made, as in former years. Notable collections received in 

 this way contained the stomachs of pileated w^oodpeckers, pigmy 

 owls, and rough-legged hawks from Oregon ; ruffed grouse from Wis- 

 consin; great blue herons from Michigan; bobwhites from South 

 Carolina; black swift's from Washington; and wild ducks from 

 Peru. 



WORK ON THE FOOD HABITS OF TOADS AND MAMMALS. 



Nearly 600 stomachs of 3 species of toads were examined during 

 the year. Toads are notable for taking a great variety of food, and 

 in 500 stomachs of the common toad (examined in this and preceding 

 fiscal years) no fewer than 1,200 food items were identified. This 

 great diversity of food makes the work slow and tedious. During 

 the year a leaflet was prepared summarizing the economic status of 

 the common toad, with some notes on its habits, and another on 

 poisonous snakes of the United States w^as manifolded and dis- 

 tributed. 



More than 300 stomachs of mammals were examined, including 

 chipmunks, pocket mice, rabbits, moles, shrews, bears, caribou, moun- 

 tain sheep, moose, and deer. Knowledge of the food of grazing 

 animals is of considerable value in connection with the bureau's 

 investigations of the reindeer industry in Alaska and in determining 

 the relation of the feeding habits of big game to live-stock grazing. 



BIOLOGICAL INVESTIGATIONS. 



In general, the technical work of this division has continued along 

 lines supplying the definite basic information required for the proper 

 discharge of the various duties of the bureau, such as the enforce- 

 ment of the migratory-bird treaty and the Lacey Acts, the adminis- 

 tration of mammal and bird reservations, the conservation of game 

 birds and mammals, and lines bearing upon the relations of birds 

 and mammals to agriculture, forestry, and animal husbandry. The 



