DATA ON THE RELATIVE CONSPICUOUSNESS 

 OF BARRED AND SELF-COLORED FOWLS 1 



DR. RAYMOND PEARL, 

 Maine Agricultural Experiment Station 

 I. Physical Data 



The purpose of this note is to put on record a rather 

 striking physical fact, and to discuss briefly its biological 

 significance. Some two years ago Davenport 2 published 

 a short note regarding the relative number of self-colored 

 and of " penciled or striped" chicks killed by crows one 

 afternoon, at Cold Spring Harbor. The rather striking 

 result was that out of 24 birds killed, only one was other 

 than self-colored. The communication closes with the 

 I'ol lowing words: "This fragment, then, so far as it 

 goes, indicates that the self-colors of poultry, which have 

 arisen under domestication, tend to be eliminated by 

 the natural enemies of these birds, and the pencilled birds 

 are relatively immune from attack because relatively 

 inconspicuous." 



Some photographs taken on the poultry range of the 

 Maine Experiment Station this past summer illustrate 

 this point made by Davenport as to the relative conspic- 

 uousness of self-colored birds in so striking and com- 

 pete a manner as to warrant their publication and a 

 critical discussion of their significance. These photo- 

 graphs were made without any thought whatever at the 

 time that they were going to bring out the relative con- 

 spicuousness of different plumage patterns. Indeed, it 

 was not realized that they did so until the finished prints 

 were given to me by the station photographer, Mr. Roy- 



tion, No. 23. g 



•Davenport, C. B., "Elimination of Self-Colourc! Birds," Nature, Vol. 

 78, p. 101, 1908. 



107 



