1576 U.S. NATIONAL MUSEUM BULLETIN 23 7 p^t 3 



to bill, singing and fluttering their wings," they disputed the patch of 

 prairie habitat which for each, holding dominantly a mate and a nest, 

 was "his." 

 Mickey describes the progress of one of these conflicts: 



An interesting situation arose early in June, 1938, when a new bird, M10, 

 attempted to encroach upon the territory of an established bird, M2, at the same 

 time and close to the same place that a nest was being constructed by M2's mate. 

 M10 was an aggressive bird and finally succeeded in establishing himself in a small 

 area * * *. When he secured a mate, it so happened that she chose a site for her 

 nest close to the disputed boundary. On July 7, I watched these two pairs of 

 birds for an hour or more. M10 was engaged in flight-song within his own ter- 

 ritory when I arrived. After each descent, he hovered over the nest site, and then 

 flew directly over into M2's territory, uttering a sharp tweet-twur on the way. M2 

 immediately flew toward M10, singing. They met head on and rose high in the 

 air; then, bill to bill, singing lustily and with wings beating vigorously, they 

 dropped to the ground, and each retired to his own territory. This performance 

 was repeated eight times within twenty minutes. 



Once boundaries were firmly laid out and apparently recognized 

 by the adjoining claimants, an alert kind of truce apparently pre- 

 vailed, broken only now and again by aerial encounters. Not that 

 this put a stop to the singing. On the contrary. Writes Mickey, 

 "after longspurs settled on their territories, they sang from or over 

 these areas at intervals throughout the day and well into the evening." 

 Thereafter apparently less and less energy was directed toward the 

 maintenance of defensive attitudes and more and more toward the 

 center of interest in the territory, the mate, and later the nest. 



Courtship. — In its own way, the courtship display of McCown's 

 longspur, while it does not have the drama of the parachute descent, 

 is in the terrestial world of buffalo stems, blue lupine and sage, a 

 spectacle in minature. In early June A. D. DuBois (1937b) came 

 upon a "very pretty demonstration" of this amatory manuevering: 

 "On the ground * * * a male McCown longspur pranced around his 

 mate in a circle about one foot radius, holding the nearer wing stretched 

 vertically upward to its utmost, like the sail of a sloop, showing her 

 its pure white lining, while he poured forth an ecstatic song." 



It is the unexpectedness of the behavior that intrigues the beholder. 

 The quick upraising of the dark wing and the sudden revelation of 

 the white lining, shining silver in contrast to the darker body, is a 

 rather astonishing performance, made all the more fanciful by the 

 comparative diminutiveness of the actors. It reminds me of the 

 courtship ballet of the buff-breasted sandpiper I saw in South Dakota 

 where the male, with both wings elevated almost like an upland 

 plover just alighting on the ground and the body held almost per- 

 pendicular, moved in a half-circle about the female, the white wing- 

 linings satin shiny beside the buff of the body. 



