BUREAU OF BIOLOGICAL SURVEY. 263 



on farms and in back yards. Boys' and girls' clubs have joined 

 in the movement, and the number of rabbit growers in the country is 

 rapidly increasing. 



FUR-BEARING ANIMALS. 



Studies of the adaptability of native fur-bearers to domestication 

 have been continued at the Experimental Fur Farm, in Essex County, 

 N. Y. The animals studied comprise blue foxes, minks, martens, 

 fishers, and skunks. 



Valuable results have been secured from the experiments relative 

 to the feeding, housing, and general management of these animals. 

 Suitable inclosures have been erected for the animals and equipment 

 provided for preparing and preserving food. 



In addition to investigational work at the Experimental Fur Farm, 

 close touch has been maintained with fur breeders and all phases of 

 the fur industry, from the care of animals to methods of dressing, 

 dyeing, cleaning, and storing furs, in order to make this informa- 

 tion available to the interested public. Investigations have been 

 made of the basic structure and quality of various furs and of para- 

 sites and diseases affecting fur-bearers under domestication. 



ECONOMIC ORNITHOLOGY. 



The leading activities in economic ornithology have had to do with 

 more or less destructive species of birds and with special cases of 

 bird damage. Owing chiefly to the bureau's investigations of many 

 years, the economic value of most of our native birds has been proved 

 and recognized by protective legislation, until protection of species 

 has advanced to a high degree and the birds have increased in 

 numbers. In a few instances ^his increase has brought about changes 

 in their economic relations and has resulted in damage to crops. It 

 will be possible, however, under the terms of the migratory bird 

 treaty act, to take steps for the control of certain species that at 

 times become injurious. Similar action will be possible under State 

 laws for certain other species. Bird protection in the United States, 

 though entering upon a new phase, will, in general, be even more 

 thorough than in the past, but at the same time special effort will 

 be made to eliminate losses due to bird depredations, whether spo- 

 radic or otherwise. 



FISH-EATING BIRDS IN RELATION TO THE NATIONAL FOOD SUPPLY. 



At various times in the past, but especially since the United States 

 entered the world war, fishermen have claimed that fish-eating birds 

 greatly reduce an important national food supply, and therefore 

 should be denied protection. To ascertain the facts the bureau has 

 undertaken a comprehensive investigation of the whole problem. 

 Studies are being made of the feeding habits of birds on the bird 

 reservations, and all of the stomachs of fish-eating birds in possession 

 of the bureau have been examined, as well as important collections 

 loaned by the museums of the University of Michigan and the 

 Canadian Geological Survey. Field investigations have been un- 

 dertaken and will be continued to determine the habits of several 



