Summary 143 
the upper surface has a triangle of brown at its tip, the under 
surface is white except the throat, which is grey. 
9. Enemies. In the early breeding season the enemies of 
the young are weather and a scanty food supply. The weather 
may result in snows which bury them from sight. The scanty 
food supply may result in the starvation of one or more of the 
nestlings. Starvation results from the automatic feeding reac- 
tion of the adults wherein the nestling nearest that part of 
the nest which is habitually approached by the adults will 
receive the first feeding; if the food is scanty this bird will 
receive nearly or all of the food. Only when food is so abun- 
dant that the first nestlings fed do not swallow promptly will 
the remainder of the brood be fed. In this case food is with- 
drawn from the first mouths and put in the next and so on 
(as Herrick, in “Home Life of Birds” has shown). The female 
Lark rarely brings more than will go into one mouth; the male 
may feed two or more, but never four or five at a time. Those 
young Larks that have a few hours advantage in hatching (a 
full day in several cases in the early spring), will have the 
advantage in size that will allow them to push to that side of 
the nest over which the food always comes. They survive, 
the others may perish. Such occurred in many observed nest- 
ings in April. 
Predacious enemies cause a greater and greater loss as the 
season advances into June and July. The optimum season is 
shown to be May. 
10. The Cowbird and the Lark. One case of Cowbird para- 
Sitism 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, the adult Lark will tolerate the parasitism, 
the food of June and July is suitable, so that other reasons 
prevent more extensive parasitism at this later season. 
11. Protection of the young. The young leave the nest, 
normally, on the tenth day, some three to four days before 
they can fly. Their protection during this interval is silence 
and a very effective “freeze” or “crouch-concealment.” Their 
plumage is remarkably adapted for this. The actions of the 
