350 Bird -Lore 



Nevertheless, it has become widely distributed, and where local conditions 

 are suited to its peculiar needs as a terrestrial bird, it thrives in widely varying 

 climatic surroundings from the cold, moist Arctic tundras to the burning deserts 

 of Mexico, 



It is common even on the Andean plateau of Bogota, Colombia, though 

 between this distant locality and southern Mexico no form of the species is 

 known. And here we have an ornithological index of climatic changes, the 

 significance of which strongly tempts speculation. With birds which vary 

 geographically as much as do the Horned Larks, the problem of field identifica- 

 tion becomes difficult and its solution is apt to be far from satisfactory. Fortu- 

 nately, however, many of these forms are restricted to certain areas, and while 

 in the winter the more northern races invade the ranges of those to the south, 

 the student may, at least in the nesting season, name the bird seen by the 

 locality in which it is found. I make no attempt, therefore, to describe racial 

 differences but refer the student to the map accompanying Dr. Oberholser's 

 paper. As the race which will doubtless come to the attention of the largest 

 number of Bird-Lore's readers, I describe the plumage changes of the Prairie 

 Horned Lark. 



Prairie Homed (Shore) Lark (Otocoris alpestris praticola; Figs. 4, 5.) In 

 nestling plumage a Horned Lark looks more like the chick of some gallinaceous 

 bird than the young of a passerine species. Or, expressed technically, it sug- 

 gests a precocial rather than an altricial bird. This juvenal plumage is brownish 

 above, the feathers being tipped with buffy spots, the breast is paler, with an 

 admixture of black, the throat and abdomen whitish, the former being some- 

 times slightly tinted with pale yellow. 



The postjuvenal (first fall) molt is complete. The first winter plumage 

 resembles Fig. 5. Male and female are much alike, but the former has more 

 black on the forehead and usually fewer streaks on the breast. There is no 

 spring, or prenuptial molt, and the summer dress is acquired by wear which 

 more clearly reveals and more sharply defines the black areas of the breast 

 and head. 



With the fall molt feathers are acquired with fringes which partly conceal 

 these areas. There is now little or no difference between young and adult 

 birds, but the latter, as a rule, have fewer streaks on the breast. 



As the frontispiece shows, the Prairie Horned Lark (Figs. 4, 5) is a slightly 

 smaller bird than the Horned Lark (Fig. 5), from which it further differs in 

 having the forehead postocular region and line over the eye white instead of 

 yellow, and there is less yellow on the throat. 



The character of the variations of the other races of this species are indicated 

 by the remaining figures in our plate, from the bleached race of the desert to 

 the deeply colored ones of more humid regions. 



