OTHER INSTINCTS. 139 



As this act is performed by young and old alike, and by young that have never learned 

 it by example, it must be regarded as instinctive, and I venture to suggest that it probably 

 represents the foundation of the more highly developed tumbling instinct. 



The behavior of the Abyssinian pigeon, which, when "fired at, plunges downwards so 

 as to almost touch the sportsman, and then mounts to an immoderate height," may well 

 be due to the same instinct. The noise of the gun, even if the birds were not hit, would 

 surprise and alarm it, and the impulse to save itself from danger would naturally take the 

 form determined by the instinct, if the instinct existed. This seems to me more probable 

 than Darwin's suggestion of a mere trick or play. 



Bearing on the above discussion of the instinct of tumbling, the editor finds 

 a quotation from an article in Nature 1 to the effect that "pigeons have all three 

 semicircular canals well developed." Concerning this statement the author 

 remarked that "possibly the center of balance is so placed in these pigeons as 

 to facilitate the tumbling." 



Three letters from correspondents relate to the tumbling phenomenon, and 

 were evidently intended for publication as illustrative of some of the points treated 

 in the quotation that has just been given. 



"What you have to say about the 'habit of tumbling' in pigeons prompts me to ask if you have 

 ever heard that scoters, when flying in flocks at a great elevation, will almost invariably descend 

 nearly vertically almost to the ground or water if a gun be fired beneath them. I have often seen 

 them do it. I remember even firing at a flock which was approaching at a height of more than 1,000 

 feet and then with the second barrel, killing one of them as the flock dashed past me low over the 

 water after their descent. Most of our sea-fowl hunters know this trick and practice it more or less 

 often and successfully. It is the report of the gun, not the charge which it contains, which brings the 

 birds down." (William Brewster, of Cambridge, Massachusetts. Nov. 23, 1899.) 



"Last summer I observed a common mourning-dove in flight which twice within a distance of an 

 eighth of a mile went through the process of tumbling like a common tumbler pigeon. I do not know 

 if this is a common habit of the mourning-dove or whether it is of any interest. If you are interested 

 I would be glad to tell you anything further you may ask so far as I observed. I have not known 

 that wild birds had this habit." (Professor M. M. Metcalf, of Baltimore, Maryland, Jan. 4, 1900.) 



In response to a request for further details of this instance of tumbling in the 

 mourning-dove, Dr. Metcalf wrote as follows: 



"Mrs. Metcalf and I were driving one evening last July hi the Fox River Valley, north of Elgin, 

 Illinois, when we saw the tumbler mourning-dove. It was about sun-down. I remember thinking 

 the birds were probably bound for their roost, which I thought might be near the river some 2 miles 

 east of us. There were three birds about 800 feet apart, flying fast in a direction almost due east. 

 The middle one showed the peculiarity in flight. I have seen tumbler pigeons but few times, and 

 could never tell what were the exact evolutions of the birds. The impression from this mourning- 

 dove was the same as from tumbler pigeons I have seen a sudden cessation of onward flight, a 

 peculiar fluttering, the bird dropping backwards, then recovering its balance, and going on as 

 swiftly as before. The drop was, I should say, about 12 feet, Mrs. Metcalf thinks more. The bird 

 tumbled (?) twice in about an eighth of a mile. I watched them about as far beyond the point of 

 second tumbling and saw nothing of the sort again. 



"It was wholly different from a stopping in flight such as oneoften sees. The bird evidently lost 

 its balance and recovered again. The three were flying swiftly, one behind the other, over prairie 

 pastures. They flew low, within easy gunshot from the ground. When the first tumbling occurred 

 the bird was about 400 feet from me. It did not pass quite over the carriage. No other birds were 

 seen by me at the time, nor did I observe anything of interest in this connection. The first tumbling 

 occurred in the middle of a pasture west of the road. The bird tumbled a second time after flying 

 over a fence one field west of the road. There was a single tree about 150 feet from the bird toward 

 myself which the bird had just passed when it tumbled a second time. The appearance of the evolu- 

 tion seemed to me to correspond to that of tumbling. There was the same startling fluttering effect. 



1 The Origin of Tumbling of Pigeons, Nature, 1901, p. 395. 



