THE UNCHARTED SKY 119 



the nesting season a bird's heart beats faster. 

 The heat of a bird 's body will hatch the eggs, even 

 in the coldest weather, but supposing the weather 

 should suddenly become too hot, what could a bird 

 do to cool the eggs? 



*'Only in a very few and very rare instances 

 does a bird realize that her eggs may need to be 

 cooled and these are birds who live always in 

 warm climates. 



''Wallace has authoritatively reported that 

 Gulls on the Amazon carry drops of water in their 

 beaks to drop on the eggs. The Black-backed 

 Courser, of the Nile, will fly just above the w^ater 

 of the river, dipping her breast-feathers from 

 time to time till they are quite wet, and therewith 

 will dampen the sand above the eggs, the evapo- 

 ration of the water keeping the eggs cool. But 

 these, as I said, are rare cases. 



"The general rule holds true that birds nest in 

 the springtime in the northern part of their range. 

 Some birds are even more extreme than this, and 

 -will not only breed in the north, but even do so in 

 winter. Thus the Great Horned Owl will lay her 

 eggs in the coldest latitudes in January and brood 

 them through the most intense blizzards. 



''Think, Shan, of a bird which lays her egg 



