The stifled bird rises in spite of the fact that his head does not point upwards like that of a pheasant rising to top the trees. The partridge rises without any appearance of change of angle in his body, and when he reaches the apex he does not turn over backwards, as has been said of him, but starts to fall from the position of ordinary horizontal flight. You will generally find him dead upon his back, but the reason of this is that the resistance of his outstretched wings in falling turns him over, and they cease to resist the air when he is on his back. It is a case of movement in the direction of least resistance.
A bird which is brought down instantly by a shot in the head generally jumps about or flaps his wings when on the ground; one would think that he could not do this if he was entirely unconscious, but if he has any degree of consciousness the head-struck towerer must have very much more, just as the stifling bird has, so there must be many degrees of semiconsciousness in wounded partridges.
It very often happens that the most experienced will mistake the dead bird’s fall for that of a runner, and a runner’s for that of a dead bird, but the latter is less frequent. The runner generally flaps a wing as he falls, shows the white of the other one and holds his head up; but all these signs taken together do not prove him to be a runner, because he may have had a lung shot as well, and then he will die upon the ground. Again, a runner may deceive in the other way, he will sometimes fall as if unconscious and then recover and run away. The runner which is just wing-tipped and can fly a long way, sinking slightly until he touches the ground, will not fly again, but generally proves to be a very strong pedestrian indeed.
Several different kinds of hits cause birds to drop their legs instantly, and I fancy that when this happens they are always found where they fall, near or far. The most common of these is the lung-shot bird, then there is the back-broken bird, which does the same, and may also be known by the wobble of his flight—an up-and-down movement, like a boat in a heavy sea. Then there is the leg-broken bird which is likely enough to fly again, but not to run, that day at least. A broken-legged bird generally only has one leg down, whereas a dead bird generally drops both, no matter how far he is to fly before he dies. I think a bird very seldom bleeds to death from a shot wound in the neck vein, but probably this must happen sometimes. I am inclined to think that when the only wound is in the blood-vessels of the neck the bird would fly so far, losing blood all the way; that when he was picked up the cause of death would not be recognised, and I think this is the reason why this kind of wound is so seldom seen. It does not follow that it infrequently occurs.
A shot which breaks the spinal cord is as instantaneous in effect as one which enters the brain, and brings the bird down at once, but not with what is called a broken neck, for I never saw a broken neck in grouse, partridge, or pheasant, unless the keepers had wilfully done it in order to kill a wounded bird. It is a very bad plan to kill any game this way, and especially grouse, for without the bone of the neck to suspend them on the stick the weight often causes the body to drop and be lost in the heather. The skin alone is not strong enough to carry, at any rate, the young birds, especially when boys drag their feet and bodies through the tall heather.
It has been said that the reason partridges “tower” is that they are obliged to lift their heads upwards in order to get their breath, and that their bodies follow where their heads point. This can hardly be the reason, because we have two kinds of “towerers” to deal with, and besides, many a blackcock on taking wing and going away horizontally, nevertheless holds up his head and looks at his disturber over his back, but he does not go upwards in consequence. I do not believe that the upward flight is caused either by any rudder-like action of the tail, although that is, perhaps, possible.
Probably the wings are so set by Nature that their beats not only counteract gravity, but something more than this, and it possibly requires the will of the bird in steering to make him keep a horizontal course. The concave undersurface offers more resistance to the air than the upper convex surface. Hitherto I have considered that this arrangement was meant to negative gravity when the bird was urging its forward course, but when one remembers that young birds with half the power of flight of the old ones nevertheless can rise quite easily, and seem to maintain a horizontal course quite comfortably—that is, their inferior wings in ordinary up-and-down beats are equal to the resistance of gravity—consequently, it appears almost certain that the ordinary beats of better wings are much more than equal to the resisting of gravity. Or, in other words, if partridges in a state of health did not wilfully hug the ground they would rise up like “towered” birds.
I wonder whether this is the reason that day birds (which appear to migrate in their sleep, and certainly cannot travel by night at any other time than when the instinct is upon them) migrate at great altitudes. That is to say, whether they go up because they cannot help it. If so, there would be a certain altitude for each kind of bird where the wing beats influence, on the more rarified air, in sending the bird up, and the lessened power of gravity, would become equal, and at that altitude the bird would travel forward without the will being called into request to keep a horizontal course. Balloonists tell us that at great heights birds thrown out fall like stones, so that there must be an altitude where ordinary wing action ceases to overcome gravity. In any case the partridge goes upward, whether either head or lungs deprive him of part of his senses, probably of all the sense of direction except that one of keel downwards, that no bird ever seems to lose as long as he is alive.
Another reason for believing that the natural up-and-down wing beats would take any healthy bird upwards as well as forwards is to be found in the necessity of the moult. If the full wing beats only kept the horizontal course then it would probably happen that the loss of a single flight feather would have the effect that gravity would gradually overcome the horizontal tendency and pull the bird downwards; but that does not appear to be true, and this is additional reason for believing that the up-and-down wing beats with a horizontal keel much more than overcome gravity, and that consequently when a bird cannot direct its own course it goes upwards, because it is built to do so, and to overcome the downward drag of gravity by the mere up-and-down wing action and a level “keel.”
G. T. Teasdale Buckell.