352 BULLETIN 17 9, UNITED STATES NATIONAL MUSEUM 



One case of cowbird parasitism was observed and followed. A 

 lark, which hatched before the cowbird, came to maturity. The 

 cowbird probably did not. It is suggested that the early nesting 

 season and the exposed habitat may mitigate against such parasitism 

 as may also the early departure of the young larks from the nest. 

 However, since the adult lark will tolerate the parasitism and the 

 food of June and July is suitable, other reasons prevent more exten- 

 sive parasitism at this later season. 



The young leave the nest, normally, on the tenth day, some three 

 to four days before they can fly. Their protection during this inter- 

 val is silence and a very effective "freeze" or crouch-concealment. 

 Their plumage is remarkably adapted for this. The actions of the 

 parents, especially the female, with her abandonment concealment, 

 are calculated to take advantage of the protective color of nest and 

 young at all ages. 



Young leave the nest usually by following a parent that has brought 

 food. One case was noted wherein a female enticed a belated nestling 

 from the nest with a food morsel. The young fly in about five days 

 after leaving the nest. They hop for some days after nest leaving, 

 whereas the adults walk. This hopping may be anatomical or an 

 atavism. 



Plumages. — The recently hatched nestlings are rather heavily cov- 

 ered with down, a necessary protection against sun and cold in their 

 exposed location. The down is cream-buff in color. At nest-leaving 

 age the young lark is in full juvenal plumage but presents an appear- 

 ance quite unlike that of the adults; each feather of the upper sur- 

 face has a triangle of brown at its tip, the under surface is white except 

 the throat, which is gray. [Author's note: Subsequent molts and 

 plumages are described under the northern horned lark.] 



Food. — McAtee (1905), in his extensive account of the food of the 

 horned larks, writes that in August and September many grasshop- 

 pers are taken (7.1 and 8.9 percent of the total food, respectively) and 

 that weevils constitute 18 percent of the food in August. He says fur- 

 ther that spiders are taken in every month. The conspicuous weed 

 seeds that he lists (foxtail grasses, smartweeds, bindweeds, amaranth, 

 pigweeds, purslane, ragweed, crab and barn grasses) are probably 

 largely consumed in fall, winter, and early spring. The total of 79.4 

 percent of vetetable matter taken in the year, as given by McAtee, 

 is made up largely of these weed seeds. He found about 40 percent of 

 food taken in August to be animal matter, 20 percent animal matter 

 in September, between 10 and 20 percent in October, 5 percent or less 

 in November, about 2 percent in December, 1.73 percent in January, 

 and 3.11 percent in February. The animal matter of January and 

 February consisted principally of weevils and cocoons of tineid moths. 



