Page:Territory in Bird Life by Henry Eliot Howard (London, John Murray edition).djvu/273



have now considered the various ways in which the territory is useful in furthering the life of the individual. We have seen that, in some cases, there is competition for stations where the egg or eggs can be deposited and incubated in safety; that, in others, there is competition for stations capable of furnishing an adequate supply of food for the young; and that the establishment of "territories" not only renders the attainment of reproduction for the individual secure, but serves so to regulate the distribution of pairs that the maximum number can be accommodated in the minimum area. This being so, the question arises as to whether competition for territory is strictly limited to individuals of the same species, or whether it may not occur also between different kinds of birds, providing always that similar conditions of existence are required. First of all I shall relate a number of facts which will serve to show the nature and extent of the warfare, and I shall