338 BULLETIN 17 9, UNITED STATES NATIONAL MUSEUM 



portions of the region, were referable to the new form described by 

 Dr. Oberholser (1902), 0. a. enthymia^ while those collected on the 

 alkaline plains and sagebrush plains farther west were more clearly 

 referable to letioolaema. 



Courtship. — Although the habits of the various races of the horned 

 lark are all very much alike, different observers have described them 

 somewhat differently, illustrating certain phases of behavior more 

 clearly than has been done by others. For this reason, I shall, at the 

 risk of some duplication, quote freely from two excellent papers by A. 

 Dawes DuBois (1935 and 1936) on the habits of the desert horned lark. 

 He noted that the male, in his upward nuptial flight, usually ascends 

 at an oblique angle, but that against a strong wind he rises almost 

 vertically. He then goes on to say (1936) : "After remaining aloft for 

 a time, singing his best song, which comes to the human ear but 

 faintly from so great a height, the bird Suddenly folds his wings and 

 drops like a bullet. With ever increasing velocity he descends until 

 one might fear for his life ; but he spreads his wings just in time to 

 avert a violent end, skillfully turning his course into a glide which 

 carries him horizontally, near the ground, until his momentum has 

 been spent. He then alights quite easily, as though nothing important 

 had happened. * * * j doubt that the bird world holds a more 

 awe-inspiring event than this headlong drop from the sky." 



He thinks that this spectacular dive "far surpasses the performance 

 of the nighthawk" but does not compare it with the thrilling dives 

 performed by some of the hummingbirds, which seem equally inspir- 

 ing. He says : 



Another ceremony of the season is the fighting exhibition, which takes place in 

 the air a few feet above the ground. The two males engaging in it begin their 

 advance and attack while on the ground but immediately rise together in a 

 whirl and flutter of gallantry. * ♦ * There seems never to be an injury, nor 

 even a victory. I have never seen a drop of blood drawn or a feather lost in the 

 encounters. * * * 



The third sort of maneuver is an exciting chase. Two, three, or four birds 

 usually take part in it. They fly in close formation with great swiftness and re- 

 markable skill. It looks like a game of follow the leader, with instant response 

 to every 'ihange of the leader's course — a course of rapidly changing, meandering 

 curves. 



Nesting. — Mr. DuBois (1935) has given us a very full account of 

 the nesting habits of this lark in Teton County, Mont., based on four 

 years of study of 58 nests. His data are given in far too much detail 

 to admit of more than a few extracts from them, as follows : 



Two peaks of nesting activity occur, one about the end of April, the other early 

 in June, indicating two broods in a year. * * * The Desert Horned Larks 

 avoid the more luxuriant growths which are to be found in moist situations 



