Territory in Bird Life

by Henry Eliot Howard

So much for the controlling influence of "position," which alone seems to me sufficient ground for believing that the fighting has reference to the territory. But it is not the whole of the evidence.

Now if it were possible to demonstrate by actual observation that those males which had not established territories were not pugnacious, we should have something in the nature of proof of the correctness of this view. Demonstrative evidence of this kind is, however, unattainable. Yet we can come very near to obtaining it by reason of a peculiar feature which marks the process of acquiring territory—the neutral ground. The Lapwing will serve as an illustration. In the previous chapter I referred to the small flocks that appeared in the accustomed water meadow early in February, and I described how they settled day after day in that meadow, but only in a limited part of it, where they passed their time in rest, in preening their feathers, or in running this way and that lazily searching for food; and how, at length, the flock dwindled by reason of individuals breaking away in order to secure positions on the remaining part of the meadow. Here the neutral ground is adjacent to the territories, and, while still occupied by the flock, is resorted to by the males that had deserted that flock in order to establish those territories.

Suppose now that we have the whole meadow in view from some point of vantage. In front of us are the territories, in the distance the neutral ground; and in each territory there is a solitary male, while on the neutral ground a number of individuals of both sexes are assembled, and move about freely one amongst another. So that the scene presented to view is somewhat as follows: a flat meadow, at one end of which, and at fairly regular intervals, a few solitary individuals are dotted about, each one keeping at a distance from its neighbours; while at the other end a number of individuals are collected together in a comparatively small space, apparently deriving some satisfaction from their close association. That surely is a very remarkable contrast. But let us continue our investigation, first fixing our attention upon the solitary individuals; one is standing preening its feathers, another is squatting upon the ground, a third runs a few yards in this direction then a few yards in that, stimulated apparently by the sight of food, and so on. Moreover, each one keeps strictly to a well-defined area and makes no attempt to associate with its fellows. One of the males, however, whilst roaming backwards and forwards approaches the limit of its territory, and this brings the neighbouring bird, whose boundary is threatened, rapidly to the spot. In an upright position both stand face to face, and the battle then begins; with their wings they attempt to beat one another about the body, with their beaks they aim blows at the head, and in the mêlée wings and legs seem to be inextricably mixed; whilst at intervals, driven backwards by the force of the collision, they are compelled to separate, only, however, to return to the charge—and the sound of beating wings and the feathers that float in the air are tokens of earnestness. Such scenes are of frequent occurrence; but the conflicts vary in intensity, and the circumstances under which they occur vary too, and females come and go without leaving any clue as to their ultimate intentions.

Turning now to the flock one is impressed with the friendship that seems to exist between the various members. There are, it is true, occasional displays of pugnacity which never seem to develop into anything very serious; for instance, one bird will fly at another, and a momentary scuffle is followed by a short pursuit but nothing more—nothing, that is to say, in the least comparable with the battle previously described. Of what is the flock composed? Of members of both sexes. There is no difficulty in assuring oneself that this is so. But is it entirely composed of individuals in whom development has not reached a stage adequate for the functioning of the primary dispositions? No, not entirely; for it will be observed that its number is a fluctuating one, that birds come and go, and, if a close watch is kept upon the different individuals as they leave, it will be noticed that some at least are inmates of the territories at the opposite end of the meadow—the solitary members whose behaviour we were recently watching. This fact is an important one. We were impressed, it may be remembered, with the contrast between the general behaviour of the birds at the opposite ends of the meadow. But now it appears as if the contrast were not between this individual and that, but between the behaviour of the same one under different circumstances. The male, that is to say, which, while in its territory, tolerates the approach of no other male, flies to the flock and is there welcomed by the very individuals with whom a short time previously it had been engaged in serious conflict.

But if the conditions are reversed and the flock happens to settle in an occupied territory, the attitude of the owner towards the flock is very different. In the year 1916 an incident of this kind occurred in the meadow to which reference has already been made. The weather had been exceptionally severe—very cold easterly and north-easterly winds, frost, and frequent falls of snow had affected the behaviour of the Lapwings, and seemed to have checked the normal development of their sexual routine. The males would attempt to establish themselves, and then, when the temperature fell and the ground was covered with snow, would collect again in flocks and follow their winter routine. It was on the 9th March, during one of the spells of milder weather, that the flock on the neutral ground was disturbed and settled mainly in the territory marked No. 3 on the 1916 plan, but partly on that marked No. 2. The owners thereupon began to attack the different members of the invading flock. Fixing attention upon a particular bird whilst ignoring the remainder, the No. 3 male drove it away, and then after a pause drove another away, and so on until by degrees all the invaders were banished, and the No. 2 male did likewise. The interest of this incident lies, however, in the behaviour of the different individuals of which the flock was composed; when attacked they made no real show of resistance, but accepted the situation and left. The will to fight was clearly lacking, yet their presence was a source of annoyance to the owners of the territories. A short time previously a female had accompanied one of the males and was at that time somewhere in the vicinity, but beyond this there was no evidence to show that either of them were paired, and even if the presence of the female were the reason of the pugnacity of the one, it could not well account for that of the other.

The neutral ground does not always happen to be so close at hand as in the case of the meadow referred to. Sometimes the birds will resort to a particular field, attracted probably by a plentiful supply of food, and here they collect and behave as they do during the winter, running this way and that as the fancy takes them, meeting together by accident at one moment, parting at another, according to the direction in which they happen to wander. Of animosity there is little sign; the season might be the middle of winter instead of the middle of March for all the indication there is of sexual development, and yet one knows that they will behave differently when they leave this ground, as presently they will, and return to their territories in the surrounding neighbourhood, and that there each one will fight if necessary to preserve its acre from intrusion.

It would seem, then, from this that the fighting must bear some relation to the particular area of ground in which it occurs; and unless it can be shown that there is some other factor in the external environment of the male, that is the direction in which we must look for the condition under which the instinct is rendered susceptible. One's thoughts turn, of course, to the female, but she too passes backwards and forwards between the territories and the neutral ground, and if her presence were really a conditio sine qua non of the strife, one would like to know why, when she leaves those territories and joins the flock and the males do likewise, similar conflicts should not prevail there also.

Other species have their neutral ground, but the environment seldom affords such facilities for observation as does that of the Lapwing. Even though the Moor-Hens, who are so conspicuously intolerant upon the pool, do feed together amicably upon the meadows adjoining; and the Chaffinch that is so pugnacious in the morning, does seek out the flock later in the day; yet their conditions of existence prevent our obtaining a panoramic view of the whole proceeding, and we have to study each scene separately before discovering that the relationship between intolerance and the territory on the one hand, and friendship and the neutral ground on the other, is just as strong a feature as it is in the behaviour of the Lapwing.

I shall now give a brief account of the conduct of a male Reed-Bunting which by persistent effort established itself late in the season, and I shall do so because its behaviour tends to confirm much that has been said in the preceding pages.

Early in March three male Reed-Buntings occupied a small water meadow overgrown with the common rush, and by the third week all of them were paired. On the 30th March two of the males were unusually pugnacious, and on the following day fighting continued and at times was very severe. Now I knew that the occupants of the ground in which the fighting was taking place were paired, and not doubting that the combatants were the owners of two territories marked for convenience sake Nos. 1 and 2, I was at a loss to understand the meaning of so determined and persistent a struggle. My attention, however, was presently drawn to a third bird, which also joined in the conflict and made the whole situation still more perplexing. This bird, as it soon became clear, was none other than the owner of No. 2 territory, and the one that I had previously regarded as such was a new arrival. On the following day, the 1st April, fighting continued, and in my record for that day there is a note to the effect that "No. 2 female seems to be of no interest to No. 5 male (the new arrival); its purpose seems to be to drive away intruders." On the 2nd April and subsequent days, this bird attacked every other male that approached, and not only maintained its position but ultimately succeeded in securing a mate. Here then we have two territories occupied by two males, both of which had obtained a mate. The relation of these two birds was normal, a month's routine had defined their boundaries, and conflicts were less frequent than formerly. But upon this comparatively peaceful scene a strange male intrudes. Observe the manner of the intrusion. The stranger does not wander about first in this direction and then in that, but acts as if it had some definite end in view, and establishing itself in a small alder bush which it uses as a base or headquarters, it gradually extends its dominion, gains the mastery over the surrounding ground, part of which belonged to No. 1 male and part to No. 2, and finally drives a wedge, so to speak, between the two territories.