Page:The Zoologist, 4th series, vol 4 (1900).djvu/205

Rh would often run quickly up to him, also waving them, and join in the pursuit. Had I not seen the chase of the moths alluded to I should have thought this action either bellicose or a joining or rivalry in display, though I am sure I should not have felt satisfied with either theory. Now I can have no doubt that it was simply the desire of one bird to get what another was chasing—as with fowls, ducks, &c.

To sum up what occurs to me from this and the previous day's observation.

1st. The extension, waving, beating about, &c, of the wings—whilst not in flight—is an accustomed action of these birds, indulged in on various occasions, and ready to leap out under excitement, irrespective of any more particular reason.

2nd. It is employed (with some other set forms) as a challenge to combat, and (probably) acceptation of such challenge.

3rd. The birds spread and wave their wings whilst chasing insects.

(a) Through excitement merely.

(b) Possibly to beat down a moth, &c, on to the ground (doubtful).

(c) Possibly again to catch the wind, and assist them in their swift runs when it is with them (also doubtful).

4th. They help themselves with the wings in jumping up at flying insects which they are pursuing. (Seen distinctly.)

5th. I think, but cannot be sure (and assurance is much needed), that I saw once (Sept. 4th) a bird pursue a flying insect for a short distance on the wing, and near the ground. There was no doubt as to the chase on foot, and the flight came, or seemed to come, as part of such chase.

Not only were the actions of the birds whilst running (as described) exactly like those of the one I had seen catch the moths on Sept. 1st, but it would have been difficult to reconcile them with any other hypothesis than that of the pursuit of some aerial but low-flying prey. They frequently ran the game down, pecking it down as it were, and securing it either on or just above the ground, though to-day I never once actually saw the pursued insect.

The activity becoming so general and so greatly increased at twilight is in accordance with moths beginning to fly then.