271 ) 



"TEIIRITORY IN BIRD LIFE " * 



BY 



H. G. ALEXANDER. 



" Every kingdom, every province," wrote Gilbert White, 

 " should have its own monographer." After reading Mr. 

 H. EHot Howard's latest book one is tempted to add " every 

 meadow and every cliff." 



The purpose of the book is to show that a great deal of the 

 peculiar behaviour of birds during the breeding-season, 

 commonly supposed to be connected with sexual selection, 

 is in fact due to the necessity for each pair of birds to have 

 its own territory for breeding purposes. Early in the spring, 

 Mr. Howard points out, not only the so-called "migrants," 

 but practically all other species too, change their winter 

 gregariousness for a spring exclusiveness, and repair to 

 definite territories, whether it be a few feet of cliff in the case 

 of a Razorbill, a part of a swampy meadow in the case of a 

 Reed-Bunting and a Lapwing, or of a copse or woodland or 

 garden in the case of a Chaffinch and a Willow-Wren. This 

 territory is defended against all invaders of the same species, 

 and often also, to some extent, against kindred species, 

 first by the solitary male, and later, after the female has 

 appeared, by the two birds equally. Hence the fighting 

 that takes place amongst birds during the mating-season . 

 Song, too, as well as warfare, is closely connected with the 

 defence of the territory ; on the one hand, it is a warning to 

 other prospective occupiers that the territory is already 

 occupied; on the other, it gives notice to the arriving females 

 that a male bird, with territory duly occupied, awaits a mate. 



Mr. Howard also shows why birds require such a territory 

 during the breeding-season. At other times the flock can 

 wander at will, and every member has an equal chance when 

 a good feeding-ground is found. But in the breeding-season, 

 not only are suitable nesting-sites required but, far more 

 important than this for most of the small birds, a plentiful 

 and continuous supply of food must be obtainable at the 

 shortest possible distance from the nest in order to prevent a 

 heavy infant mortality. This fact, urges Mr. Howard — and 

 the present writer partly agrees with him — is the true explana- 

 tion of migration, a habit which would long ago have died 



* By H. Eliot Howard, pp. xiii., 308. London: John Murray. 

 21/- net. 



