THE HOVERING OF THE KESTREL.
There has lately been some discussion about the hovering of kestrels: the point being whether the bird can or cannot support itself in the air while stationary, without the assistance of one or more currents of air. The kestrel is the commonest hawk in the southern parts of England, so that many opportunities occur to observe his habits; and there ought not to be any doubt in the matter. It is even alleged that it will go far to decide the question of the possibility of flight or of the construction of an aerial machine. Without entering into this portion of the discussion, let us examine the kestrel's habits.
This hawk has a light easy flight, usually maintaining an altitude a little lower than the tallest elms, but higher than most trees. He will keep this particular altitude for hours together, and sweep over miles of country, with only occasional variations—excluding, of course, descents for the purpose of taking mice. It is usually at this height that a kestrel hovers, though he is capable of doing it at a much greater elevation. As he comes gliding through the atmosphere, suddenly he shoots up a little (say, roughly, two or three feet),
