Territory in Bird Life   By: H. Eliot Howard

TERRITORY IN BIRD LIFE

[Illustration: A pair of Lesser Spotted Woodpeckers attacking a Great Spotted Woodpecker

Emery Walker ph.sc.]

TERRITORY IN BIRD LIFE

BY H. ELIOT HOWARD

WITH ILLUSTRATIONS BY G. E. LODGE AND H. GRÖNVOLD

NEW YORK E. P. DUTTON AND COMPANY 1920

PREFACE

When studying the Warblers some twenty years ago, I became aware of the fact that each male isolates itself at the commencement of the breeding season and exercises dominion over a restricted area of ground. Further investigation, pursued with a view to ascertaining the relation of this particular mode of behaviour to the system of reproduction, led to my studying various species, not only those of close affinity, but those widely remote in the tree of avian life. The present work is the outcome of those investigations. In it I have endeavoured to interpret the prospective value of the behaviour, and to trace out the relationships in the organic and inorganic world which have determined its survival. Much is mere speculation; much with fuller knowledge may be found to be wrong. But I venture to hope that a nucleus will remain upon which a more complete territorial system may one day be established.

I have to thank Mr. G. E. Lodge and Mr. H. Grönvold for the trouble they have taken in executing my wishes; I also want to record my indebtedness to the late E. W. Hopewell; and to Professor Lloyd Morgan, F.R.S., I am beholden more than I can tell.

CONTENTS

PAGE CHAPTER I

INTRODUCTION 1

CHAPTER II

THE DISPOSITION TO SECURE A TERRITORY 20

CHAPTER III

THE DISPOSITION TO DEFEND THE TERRITORY 73

CHAPTER IV

THE RELATION OF SONG TO THE TERRITORY 119

CHAPTER V

THE RELATION OF THE TERRITORY TO THE SYSTEM OF REPRODUCTION 169

CHAPTER VI

THE WARFARE BETWEEN DIFFERENT SPECIES AND ITS RELATION TO THE TERRITORY 216

CHAPTER VII

THE RELATION OF THE TERRITORY TO MIGRATION 259

INDEX 302

LIST OF ILLUSTRATIONS

Face page

A pair of Lesser Spotted Woodpeckers attacking a Great Spotted Woodpecker Frontispiece

Territorial flight of the Black tailed Godwit 54

Competition for territory is seldom more severe than among cliff breeding seabirds, and the efforts of individual Razorbills to secure positions on the crowded ledges lead to desperate struggles 64

Male Blackbirds fighting for the possession of territory. The bare skin on the crown of the defeated bird shows the nature of the injuries from which it succumbed 74

Male Cuckoos fighting before the arrival of a female 82

Two pairs of Pied Wagtails fighting in defence of their territories 86