186 CHARLES A. COBURN 



did not put the crow on a higher plane of intelligence than sev- 

 eral other birds, especially the English sparrow. 



In co-operation with Professor Robert M. Yerkes, an inves- 

 tigation of the intelligence of the crow was begun in June, 1913, 

 at the Franklin Field Station. Work was continued until late 

 September. It is planned to continue the investigation in suc- 

 ceeding summers under the favorable conditions of the station. 



The first summer's work included a general study of the 

 habits and development of the bird (to be reported after addi- 

 tional data have been obtained) and a preliminary examination 

 of its ability to discriminate brightnesses, sizes and forms. 



It soon became apparent that the adaptation of an apparatus 

 and method to the extremely wary and suspicious nature of the 

 crow was a more difficult task than had been anticipated. This 

 was accomplished after much experimenting with different 

 methods of procedure and many changes in the apparatus. By 

 the time both method and apparatus were fairly well adapted 

 to the characteristics of the crow, the summer was well gone. 



Our results are only approximations to the crow's discrim- 

 inating ability. They are of value, however, in that they indi- 

 cate certain important tendencies. A comparison of the results 

 obtained during the first weeks with those obtained the last 

 few days clearly shows the effect of improvement in method. 



Two crows were used in these experiments. They were taken 

 from a nest near the Field Station on the 6th of June. They 

 were then, probably, about two weeks old. Number 1, a male, 

 was larger and better developed when caught. When full- 

 grown it was larger and bolder and less easily frightened than 

 the female, Number 2. 



For two or three weeks after they were caught, the young 

 birds were fed earthworms, with an occasional bit of cooked 

 cereal. Gradually this diet gave way to various kinds of meat, 

 bread soaked in milk, cracked corn soaked in water, and table 

 scraps. 



The development, care, and feeding of young crows, will be 

 discussed in a later paper. 



When the two crows were about nine weeks old, they were 

 able to fly a short distance and to eat alone. They were so tame 

 that they recognized the voice of the experimenter and would 

 come when called, perch on his arm or shoulder, and eat from 



