Territory in Bird Life

by Henry Eliot Howard

THE DISPOSITION TO DEFEND THE TERRITORY

In the previous chapter I endeavoured to show that each male establishes a territory at the commencement of the breeding season, and there isolates itself from members of its own sex. And further I gave my reasons for believing that this particular mode of behaviour is determined by the inherited nature of the bird, and that we are justified in speaking of it as "a disposition to secure a territory" because we can perceive its prospective value. But the act of establishment is only one step towards "securing." By itself it can achieve nothing; for any number of different individuals might fix upon the same situation, and if there were nothing in the inherited constitution of the bird to prevent this happening, where would be the security, or how could any benefit accrue to the species?

In withdrawing from its companions in the spring, the male is breaking with the past, and this action marks a definite change in its routine of existence. But the change does not end in attempted isolation; it is carried farther and extends to the innermost life and affects what, humanly speaking, we should term its emotional nature, so that the bird becomes openly hostile towards other males with whom previously it had lived on amicable terms.

The seasonal organic condition is responsible for the functioning of the disposition which results in this intolerance, just as it is for the functioning of the disposition which leads to the establishment of the territory; and the effect of these two dispositions is that a space of ground is not only occupied but made secure from intrusion. The process is a simple one. There is no reason to believe, there is no necessity to believe, that any part of the procedure is conditioned by anticipatory meaning; the behaviour is "instinctive" in Professor Lloyd Morgan's definition of the word, since it is of a "specific congenital type, dependent upon purely biological conditions, nowise guided by conscious experience though affording data for the life of consciousness."

That the males of many animals are apt to become quarrelsome during the mating period is notorious. Darwin collected a number of facts, many of which related to birds, showing the nature and extent of the strife when the sexual instinct dominated the situation. And pondering over these facts, he deduced therefrom a "law of battle," which, he believed, bore a direct relation to the possession of a female. And it must be admitted that he had excellent ground for his conclusion in the fact not only that the conflicts occur mainly during the pairing season, but that the female is often a spectator and seems even to pair with the victor. I accepted it, therefore, as the most reasonable interpretation of the facts. But, as time passed by, incidents of a conflicting character led me to think that after all there might be another solution of the problem. And when it was no longer possible to doubt that there was a widespread tendency to establish territories, it at once became manifest that the battles might have an important part to play in the whole scheme. But how was this to be proved? What sort of evidence could show whether the proximate end for which the males were fighting had reference to the female or to the territory? Clearly nothing but a complete record of the whole series of events leading up to reproduction could supply the necessary data upon which a decision might rest. In the present chapter I shall give, in the first place, the reasons which lead me to think that the origin of the fighting cannot be traced to the female; afterwards, the evidence which seems to show that it must be sought in the territory; and finally, I shall make a suggestion as to the part the female may play in the whole scheme.

The facts upon which the "law of battle" was founded were ample to establish the truth of its main doctrine. But the evidence upon which the interpretation of the battles was based was somewhat superficial. It was based mainly upon the general observation that one or more females could frequently be observed to accompany the combatants; and if this were the sole condition under which the fighting occurred, one must admit that this view would have much to recommend it. But it is not merely a question of males disputing in the presence of a female; for males fight when no female is present, pair attacks pair, or a male may even attack a female—in fact there is a complexity of strife which is bewildering.

In attributing the rivalry to the presence of the female, it is assumed that males are in a preponderance, and that consequently two or more are always ready to compete for a mate. Her presence is presumably the condition under which his pugnacious nature is rendered susceptible to its appropriate stimulus, the stimulus being, of course, supplied by the opponent. There would be nothing against this interpretation if it were in accord with the facts; but it can, I think, be shown that the males are just as pugnacious and the conflicts just as severe even when the question of securing a mate is definitely excluded; and I shall now give the evidence which has led me to this conclusion.

In the previous chapter we had occasion to refer to the difference in the times of arrival of the male and female migrants, and we came to the conclusion, it may be remembered, that this was a fact of some importance, because it gave us a clue to the meaning of much that was otherwise obscure in their behaviour. But it is also of importance in connection with the particular aspect of the problem which we now have in view, for if it can be shown that males, when they first reach their breeding grounds, are even then intolerant of one another's presence, if their actions and attitudes betray similar symptoms of quasi-conation, if disputes are rife and the struggles of a kind to preclude all doubt as to their reality, then it is manifest that in such cases their intolerance cannot be due to the presence of the female.