156 BRANCH VERTEBRATA. 



warmer regions of America, and the Condor of the Andes. 

 The last is typical of the group, and is our largest bird 

 of prey. Its alar extent averages about nine feet. It 

 will frequently soar for half an hour without once nap- 

 ping its wings ; but how this is accomplished, has not 

 been satisfactorily explained. To man, the Condor is in- 

 offensive, nor does it often attack living prey. 



The Wlute-headed Eagle is the chosen symbol of our 

 country.* It sometimes rises in the air by a series of 

 spiral curves, and with an almost imperceptible motion 

 of its wings, until it is a mere speck in the sky. Thence 

 it may descend with lightning-like velocity. Its swoop is 

 in a cycloid, which is a line of swifter descent than a 

 perpendicular, and also easier for alighting. 



FIG. 264. FIG. 265, 



Ha li ae' tm leu co ceph ' a lus. Nan' de rus fur c<T tus. 



White-headed Eagle. (&.) Swallow-tailed Hawk. ( T V) 



The Swallow-tailed Hawk feeds upon reptiles and in- 

 sects,! but never upon birds or quadrupeds. 



* Equally indifferent to the extremes of heat and cold, as well as to a mari- 

 time or an inland life ; now honestly pursuing an independent vocation, and anon 

 acting the part of a freebooter and robbing the Fish-hawk of its well-earned food, 

 it is not an altogether unsuitable emblem of the nation. 



+ Fond of wasps, it may sometimes be seen holding a nest in one claw and 

 picking out the grubs with its bill. 



