PRESERVATION 99 



for a day or two, as any disturbance at 

 this critical time may make her desert. 



All nests in safe places are left alone, 

 except that some of the eggs are changed 

 with other beats, with perhaps a few spare 

 eggs added if the full clutch is much 

 under twenty. Changing of eggs is 

 systematically carried out all over the 

 ground, both with other estates and also 

 by free interchange between beats. Nests 

 on roadsides and exposed places are 

 treated according to the degree of danger 

 to which they seem exposed ; if there 

 appears to be a reasonable chance of their 

 survival, they are dealt with on the 

 Euston system, as described later in this 

 chapter when treating of foxes; but if 

 their prospects of success are slight, the 

 eggs are taken to the incubator as soon as 

 the clutch is nearly completed, and the 

 nest destroyed in the hopes that the bird 

 may have a second nest of seven or eight 

 eggs in a more favourable situation. 



When any misfortune befalls a nest, 

 should the sitting bird forsake or be killed, 



