29 AUGUST 1925, Page 13

THE SENSE OF HEARING IN BIRDS

[To the Editor of the SPECTATOR.] SIR,—I read with much interest the article on " The Speech of Birds" in your issue dated June 13th, which I have just re- ceived. On page 968 the following words occur : " In birds the supreme sense is sight . . . . but there is no evidence that their acuteness of hearing is at all comparable in quality with the sense of smell in dogs or moths."

With reference to the ability of birds to hear sounds, the following incident may be of interest. In the late 'nineties my wife and I were living about fourteen miles—as the crow flies— from Agra. Our bungalow was built of brick, about sixty feet long, thirty feet wide, and perhaps the same height to the top of the pointed roof. On each side was a wide verandah, and on the verandah furthest from Agra we had a large aviary in which were some fifty small birds of various kinds.

Late one evening the birds began to chirp and flutter about, and, fearing there was a snake, wild cat, or other animal near the cage, I went outside, but could find nothing to account for the birds being disturbed, and they soon settled down again. For several nights following—not always consecutive—the birds behaved in the same way, but I was quite unable to ascertain the cause. I was, however, determined, if possible, to find out the reason, and, having noticed that the birds began this strange performance about 9.30 p.m.—although at the time this conveyed nothing to me—I went out about 9.15 and concealed myself near the cage.

I watched for several nights without success, although. the birds behaved in the same way and always about the same time. But about the sixth night, as far as I can now recollect, my patience was rewarded. I heard a very faint sound, so faint that had I not been on the alert I am quite sure that I should not have heard it. But the birds immediately woke up and began to chirp and flutter as before. It was the sound

of the 9.80 gun from Agra, fourteen miles away, with the bungalow between the birds and that place !

As the boom of the gun was a low note with, consequently, a long wave length, I can understand the sound flowing round or over the bungalow, but I have never been able to understand how the birds, which were, presumably, fast asleep, heard a sound so faint that even I, with quite good hearing, and very much on the alert, could barely detect. Moreover, I attribute my hearing the gun on that particular night to the fact that there was a very slight breeze blowing from Agra to the bungalow, but on the other nights there was no breeze and yet the birds on several occasions heard the gun.—I am,