Territory in Bird Life

Territory in Bird Life is by Henry Eliot Howard. The preface says that when studying the Warblers some twenty years ago, the author became aware that each male isolates itself at the commencement of the breeding season and exercises dominion over a restricted area of ground. The book says that if the Guillemot were to hustle its neighbours from adjoining ledges, the Guillemot as a species would probably disappear.

The book says the Chiffchaff as a species would probably not endure if it confined itself to a single tree and trusted to spasmodic excursions into neutral ground for food. The book says that when we speak of song acting as a warning, we do not mean that it arouses any sensation of fear; it is but a stimulus to that part of the inherited nature of the hearer which predominates at the moment. The book describes a position in which all the available breeding ground is divided into territories, each territory occupied by one unit, the family, and each individual able to fend for itself.