“Towering” of Birds

Abstract

I HAVE read Mr. Romanes' communication on the “towering” of grouse and partridges with much interest. As he requests further information, may I be permitted to contribute the following:—I once observed a pheasant which, after being shot, flew apparently untouched for about one hundred yards, then towered ten or fifteen yards, and fell dead. As a rule birds that have towered are picked up dead, as Mr. Romanes states; but such is not invariably the case. A correspondence took place in the Field some weeks since in answer to the question: “Do towered birds ever rise again,” and several replies were elicited in the affirmative. The conclusion warranted by that correspondence seemed to be that towering arises from at least two distinct kinds of injury. In the first, the common form, the bird is struck in the back, and is always found precisely where marked down. It seems to me that in this kind of towering the perpendicular flight may be attributed to a cause perhaps other than, or at all events additional to, pulmonary hæmorrhage. I consider that hæmorrhage is a necessary factor, and Mr. Romanes makes out a very strong case in favour of its being into the lungs. That the movements of the wings are convulsive, and the explanation of the towering, I am not inclined to dispute, but I think it has yet to be proved that the convulsive flapping of wings (the directing power of the brain being in abeyance) always produces perpendicular and never merely erratic flight. Every towering bird acts in a precisely similar way. Are we to take it for granted that in asphyxia it is only certain sets of muscles, and these always in the same and to an equal degree, that are spasmodically affected? I have noticed that a towering bird very often has his legs hanging straight down (I do not allude to those cases where they are palpably mutilated), and it strikes me as being likely that paralysis of the legs and lower part of the back may have something to do with the flight being upward. A man who has paraplegia always complains that he cannot move his legs because they are so heavy. This sensation would doubtless be felt by a bird paralysed behind, and this, in addition to the loss of its steering apparatus and the co-operating contractions of the posterior muscles, would produce a loss of balance with much the same effect as though the after parts had really become disproportionately heavy. I have no desire to be dogmatic, but merely offer this as a possible assisting factor in some cases.