404 THE ZOOLOGIST* 



cap and Garden-Warbler, is the Sedge-Warbler. In 1908, owing 

 to disaster during migration or other cause, there was a great 

 shortage in the number of Sedge-Warblers, and several nesting 

 areas, including the wood with which this article is specially 

 concerned, were entirely deserted by the species. No recovery 

 in numbers was apparent in 1909, but in the following spring 

 some of the former haunts began to fill up, and three males 

 settled in the wood. But only one of these obtained a mate and 

 nested, the other two remaining solitary throughout May and 

 into June, disappearing altogether in the latter month. 



These three cases of Blackcap, Garden-Warbler, and Sedge- 

 Warbler seem to afford some evidence that the males are the 

 pioneers in the settling of new breeding areas. The fact that 

 the females follow them in smaller numbers is at least suggestive 

 of numerical inferiority in that sex. 



Beturning to the Willow- Wren. The accompanying map, 

 for the preparation of which I am indebted to my friend Mr. 

 B. M. Adam, shows the position of twenty-five nests, twenty-one 

 of which are first broods. It will be noticed that these nests 

 are somewhat irregularly distributed throughout the wood, more 

 so than the singing-posts of the males. This is to be partly 

 explained by the fact that, while the males show little preference 

 in the choice of their singing-posts, the females dislike dense 

 cover for their nests, and the latter are consequently placed in 

 whatever open spaces are readily accessible. 



It is necessary here to say a few words on these singing- 

 posts and their relation to the nests. On reaching their breed- 

 ing-haunts the males soon settle down into regular beats, con- 

 fining their feeding-excursions within certain more or less definite 

 limits. The areas comprised within these limits have been 

 designated the " territories " of the birds, and the term is a con- 

 venient one, since such restricted areas do undoubtedly exist 

 amongst many of our summer birds. At the same time my 

 experience leads me to doubt whether too much stress has not 

 been laid on the precise and sharp demarcation of these terri- 

 tories. Speaking here solely of the Willow- Wren, it seems that 

 the facts are roughly as follows : In each territory there exists a 

 tree or group of trees chosen by the male as his headquarters, 

 and here a large proportion of his time is spent prior to the 



