244 



NORTH AMERICAN BIRDS. 



the eggs of this Hawk in Montana ; that their number in a set is usuall}' 

 two, and an unspotted white. 



Genus ASTURINA, Vieillot. 



Asturina, Vieill. 1816. (Type, Falco nitidus, Latham.) 



Gen. Char. Somewhat similar to Astur, but of much heavier and more robust build ; 

 tarsi longer and stouter, tail shorter and less rounded, wings longer, etc. Bill more 

 elongated than in Astur, the cere longer, and the festoon on the comijiissure more 

 developed; nostril oval, horizontal. Wings rather short, but less concave beneath than in 

 Astur ; third to fourth quill longest; first shorter than eighth or ninth; four outer quills 



34002, ^ 



34002, %. 



Asturina plagiata. 



34002 . 



with their inner webs sinuated. Tail considerably shorter than the wing, slightly emargi- 

 nated, the lateral pair of feathers longest. Feet large and robust, when outstretched 

 reaching almost to the end of the tail ; tarsi very robust compared to the toes, about one 

 and a half times as long as the middle toe, the frontal and posterior rows of transverse 

 scutelte very distinct and regular; outer toe longer than inner; claws strong, well curved, 

 but not very acute. Sexes alike in color ; old and young plumages very different. 



This genus is peculiar to tropical America, and contains but a single 

 species, the A. nitida, with its two climatic races, nitida of South America 

 and plagiata of Middle America. The species of Rupornis, Kaup {R. mag- 

 nirostris and R. leucorrlioa), have been associated with the species of the 

 present genus, but they are very distinct. The genera (or, more properly, 

 subgenera) most nearly related to Asturina are Leucopterinis, Kaup, of 

 tropical America, and Kaupifalco, Bonap., of Western Africa. The former 

 differs mainly in more or less rounded, instead of emarginated, tail, and in 

 having the old and young plumages similar ; the latter in having the poste- 

 rior face of the tarsus without a well-defined row of transverse scutellae. 



