16 THE AUKS 



billing, bowing, etc., as those that hatch eggs. 1 The matter is well 

 worth further attention. 



There can be little or no doubt that the birds pair for life and 

 return to the same ledges each year. Whether one sex returns before 

 the other is not recorded, and there are, unfortunately, no published 

 details of the struggle for nesting-sites that must take place at this 

 period wherever there is overcrowding. 



On one occasion I witnessed what was evidently a battle for the 

 ownership of a crevice between two razorbills. It took the form of a 

 tug-of-war, both birds crouching with their beaks apparently inter- 

 locked. As the strain of the tugging fell chiefly upon the neck, the 

 heavy bodies remained much where they were. After about twenty 

 minutes of this ineffective struggle, both flew off together, alighted on 

 the water, and there continued to battle, finally diving. 



Owing to the similarity of the sexes, it was impossible to say 

 whether this contest was between males or females, or between a 

 male and a female. In studying contests for sites, the first 

 important thing to ascertain, from the scientific point of view, is 

 whether or not the males return to the breeding-haunts before the 

 females. If they do, it may follow that conquest of a nesting-site 

 carries with it possession of the female accustomed to lay there. The 

 female, on her arrival, may find a new mate awaiting her, instead of 

 the old. If she accepts him, as a matter of course it is clear that the 

 theory of sexual selection, as far as these species are concerned, falls 

 to the ground. 2 Whether such be the case or not, close observation 

 of these and other cliff-birds at the beginning of the season would give 

 very important results. Hitherto, unfortunately, their eggs have been 

 regarded as of much more importance than the birds themselves. 

 Hence our ignorance of their habits, though they are exceedingly easy 

 to watch. 



Fighting takes place at any time during the breeding season, and 



1 VGgel Mitteleuropas, xii. 221. 



J For observations on the same point in respect to the Warblers, see H. E. Howard, British 

 Warblers. 



