over, as they but make a part in general scenes and pictures, I will not separate them from their context nor any bird from its companions.
Starlings, again, furnish striking examples of the same phenomenon. Their aerial evolutions before roosting are sufficiently remarkable, but, perhaps, still more so from this point of view is the manner in which they leave the roosting-place in the morning. This is not in one great body, as might have been expected, but in successive flights at intervals of some three or four to ten or twelve minutes, each flight comprising, sometimes, hundreds of thousands of birds—the numbers, of course, will vary in different localities—and the whole exodus occupying about half-an-hour. Each of these great flights or uprushes from the dense brake of bush and undergrowth where the birds are congregated, takes place with startling suddenness, and it seems as though every individual bird composing it were linked to every other by some invisible material, as are knots on the meshes of a net by the visible twine connecting them. There is no preliminary,[1] nor does it seem as though a certain number of more restless individuals gradually affected others, but at once a huge mass roars up from the still more immense multitude, as does a wave from the sea, or as a sudden cloud of dust is puffed by the wind from a dust-heap. I am speaking here of the great main flights, which are, in most cases, of this character. The fact that quite small bands of birds will sometimes fly
- ↑ As far, at least, as observable from just outside the plantation, and to judge from the sound. But previous movements within the plantation—unless we assume a quite human organisation—would not explain what is here assumed to require explanation.
