INSTINCT AND INTELLIGENCE IN BIRDS 137 



crow in Egypt and India, where from a long and undisturbed inter- 

 course with man, it has come to build its nests in the city streets, and 

 in Cairo even before the foliage of the lebbek trees is out, often gives 

 free rein to this propensity, as was well shown by the experience of an 

 optician in Bombay, who lost a large store of steel spectacle-frames, 

 and later found them in a ruined state, worked into a nest of this 

 familiar bird. The propensity to seize bright objects, and to hide and 

 store food by burying it in the ground, a practise attributed to the 

 European crow, raven, magpie and rook, is undoubtedly instinctive in 

 origin. Their ability to find it' again would depend more upon intelli- 

 gence than in the dog, which has the same tendency, for they are pre- 

 sumably without the guiding power of scent. The Californian wood- 

 pecker (Melanerpes formicivorus) is noted for the autumnal stores of 

 acorns which it embeds in the bark of trees, but the strong instinctive 

 impulse which shapes its conduct is accentuated by the reported fact 

 that the holes so nicely drilled are occasionally filled up with stones. 



That color plays an important part in the lives of birds seems highly 

 improbable, although it is a commonplace fact that the nest in many 

 cases harmonizes perfectly with its surroundings. For several seasons 

 I made a practise of offering colored yarns, such as blue, brown, green 

 and bright red, to various species of birds, for building purposes, and 

 especially to robins and cedar waxwings ; as a rule, all colors were taken 

 indiscriminately, with very bizarre nests as a result. When white 

 threads or long streamers of cotton cloth were added, these were usually 

 taken first, and in greater quantity, apparently because they were more 

 conspicuous, and sometimes to the detriment of the builders. Thus, 

 one of the least flycatchers took and dropped so much of the cloth that 

 a white trail was finally laid from field to nest, in the construction of 

 which five times more was used than needed. The quaint structure 

 which resulted was too obvious to escape destruction, and it did not 

 endure many hours. 



The docility of birds is well illustrated by the trainer's power over 

 many species, and by the tricks which, through a system of rewards 

 and punishments, they can be made to perform. A classical illustra- 

 tion is furnished by the art of falconry, the popular sport of middle-age 

 Europe, in which the young of the wild peregrine falcon, or of some 

 other hawk, was trained to limit its instinct to kill to a particular kind 

 of game, to follow the falconer afield, to stoop to the quarry, and return 

 to its master's call. After a similar fashion the instincts of the cor- 

 morant have been molded to the will of man, and successfully used in 

 taking fish, a practise which I am informed may still be witnessed in 

 certain remote fishing communities in Japan, the trained birds descend- 

 ing from father to son. 



Modern experiments in the laboratory, which have been conducted 



VOL. LXXVII. — 10. 



