EFFECT OF EXPOSURE ON THE YOUNG 189 



food at a greater distance, can it be doubted 

 that the cumulative effect of even a few minutes 

 of additional exposure would have been detri- 

 mental, if not disastrous, to the offspring ? 



Wej speak, however, of the parents extending 

 their journeys a little farther in this direction or 

 a little farther in that, as though they could do 

 so with impunity except in so far as it affected 

 themselves, or their offspring, or the other 

 Yellow Buntings inhabiting that particular area. 

 But, most certainly, any extension would have 

 meant so much encroachment upon the available 

 means of support of other members of the 

 species inhabiting adjoining areas, whose young 

 in turn would have been liable to have been 

 affected ; and, with even greater certainty, the 

 Whitethroats, the Stonechats, the Tree-Pipits, 

 and the Willow - Warblers that had also 

 established themselves in that one corner of 

 the Common would have been hard pressed to 

 find sufficient food with sufficient rapidity. 



Let me give another illustration of a some- 

 what different kind. Lapwings, as we saw in 

 the previous chapters, establish territories and 

 guard them from intrusion with scrupulous care. 

 The young are able to leave the nest soon after 

 they are hatched, and consequently the 'parents 

 are not necessarily obliged to bring food to 

 them — they can, if they so choose, lead them to 

 the food. Whether each pair limits its search 

 for food to its territory, I do not know. But 

 even supposing that all ownership of territory 

 were to lapse directly the young were hatched, 



