ON THE SENSE OF SMELL IN BIRDS. 



By M. Xavier Raspail. 



Four of the five senses arc usually considered to be more or less obtuse 

 in birds. Their sight alone is acknowledged to be more perfect and 

 complicated than that of mammals. In regard to smell, some authors 

 maintain that it is very slightl}' developed in animals of this class, those 

 which feed on carrion being guided to their prey exclusively by sight. 

 Others go so far as to say that this sense scarceh' exists among birds. 

 It is, however, generally admitted that nocturnal birds of prey have a 

 pretty fine sense of smell. 



The truth is that it is extremelj^ difficult to observe birds in such a 

 waj^ as to make out precisely what their olfactory capacity is, since 

 their sight and hearing are sufficient of themselves to put them on their 

 guard against anything that may happen anywhere near them; and 

 when they seek their food it is not easy to ascertain that their sight 

 has not informed them of its whereabouts. 



But if these circumstances have made it possible to overlook the 

 sense of smell in birds I can not see what can have given rise to the 

 notion that their hearing is imperfect. It is, at any rate, easy enough 

 to convince oneself of the contrary, and so to rectify one at least of 

 the numerous errors of accepted science. 



Many a time have I seen a bird fly suddenly awav for nothing ])ut 

 the noise of cocking a gun more than -i rods (20 meters) off, the 

 sportsman being quite Invisible behind the peephole in the face of 

 the blind. All gamekeepers know how prudently one has to approach 

 trees where crows are perching, even at night, and this is still more 

 true of ringdoves (ramiers). The smallest twig cracking under foot 

 is enough to send the whole flock away long before the sportsman 

 would have succeeded in finding them had they stayed. And the proof 

 of the fineness of their hearing is that they know whether the crack- 

 ing of the dead wood has been caused bv man, Avhom they particularly 

 dread, or by a prowling beast. I have observed that the passage of a 

 herd of deer under the trees where crows are passing the night does 

 not disturb them. 



^ Translated from a t'oiiimuuieation to the Zoological Society of France. 



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