72 BIRDS OF THE WORLD 



in many ways resembles the Gyrfalcon' It has a wide 

 range throughout North America and a large part of 

 South America. The sexes are coloured alike — ^blu- 

 ish-slate above, a somewhat lighter tint below, the 

 lower part of the breast and upper part of the legs 

 barred with dark colour. The under-surface of the 

 wings is also barred. 



The Duck Hawk is very strong and swift in flight, 

 and very fierce and aggressive in character. It 

 pounces upon its prey from an elevation, easily cap- 

 turing such fast-flying birds as Wild Ducks, and even 

 attacking Geese when pressed by hunger. 



From the Falcons we pass to the Vultures, a group 

 which possesses many interesting points for considera- 

 tion. Vulture-like birds taken as a whole are by no 

 means all closely related one to another. Divided into 

 Old and New World Vultures, the latter constitute a 

 very ancient family, standing apart from the Hawks, 

 Buzzards, Eagles, and Falcons. If we take these last 

 as representing so many branches of a common stem, 

 then the Vultures may be regarded as forming a simi- 

 lar independent stem, both arising, however, from a 

 single trunk. The letter Y may well represent this. 

 The different kinds of Old World Vultures may be 

 pictured as forming so many branches from the left- 

 hand, and the Hawks, Buzzards, Eagles, and Falcons 

 as so many branches from the right-hand branch of 

 the Y, the stem of which indicates that both main 

 branches with their ramifications came from the same 

 stock. 



The New World Vultures, however, form a group 

 by themselves; they are the terminal branches of a 



