VOl 'lsa5 XI1 ] Townsend, Notes on the Rock Dove. 313 



lutions in shore birds and concludes that they are protective in 

 character, originating in attempts to evade birds of prey and after- 

 wards employed against man. He points out the resemblance to 

 wave movement or sea-spray and believes it to be a case of pro- 

 tective resemblance with the object, not of deceiving the hawk as 

 to the reality of the birds, but of baffling pursuit, — all of which 

 is interesting and suggestive. 



At any sudden noise, like the bursting of an automobile tire or 

 an explosion of gasoline in a muffler, a flock of Pigeons will in an 

 instant mount into the air, no matter how busy they may have 

 been in feeding, and fly about for some minutes before they return. 

 A flock of Pigeons roosting on the ledges of the buildings, on Tre- 

 mont Street when startled by an explosion whir away but often re- 

 turn towards the facade only to double back again. Dr. W. M. 

 Tyler has suggested to me that these birds are acting from fear in 

 the same way that their feral ancestors would act if pursued by 

 an eagle or hawk. Edmund Selous x says of the wild birds: "In 

 effecting their numerous escapes, the face of the rock stood them 

 in good stead, and they deliberately made use of it, in my opinion, 

 for, dashing in and out, they would cling to it or double against it 

 in places where eagles, as larger birds, could not follow them so 

 deftly, and had perforce to check their speed." Of course the 

 explanation may be, as Dr. Tyler also suggested, that the birds, 

 about to return to their perches, are driven away again and again 

 by the recurring fear. When so engaged in flight, if a second 

 explosion occurs, the whole flock suddenly drops or darts down a 

 few feet while still continuing its rapid course. One cannot help 

 thinking of the similar actions of Shore Birds at the discharge of a 

 gun. I have seen a flock of Black-bellied Plovers dart down in its 

 flight when a gun was fired in another direction some distance off, 

 and, no doubt, under similar circumstances a poor marksman has 

 believed his shot had entered the flock and has wondered that no 

 birds had fallen. The very loud automobile discharge near at hand 

 would naturally startle any bird, but I have seen a flock of Pigeons 

 act in a similar way when theVxplosion was so distant that it was 

 but faintly heard. One could build up a fanciful theory to the 



i The Bird Watcher in the Shetlands, 1905, p. 158. 



