890 U.S. NATIONAL MUSEUM BULLETIN 237 part 2 



feet of the ground; the highest I found was 25 feet up in a post oak. 

 The ground nests were usually shaded by a lone broad-leafed plant 

 or by a grass tuft, but occasional ones were out in the open with no 

 shade whatever. 



In the short-grass prairies of the Oklahoma panhandle, where 

 there are trees, the nest is usually on the ground in a bare or eroded 

 place. G. M. Sutton informs me that on the Edwin S. George Reserve 

 in southeastern Michigan, where the bird was not common from 1933 

 to 1950, it nested on the ground in open, sandy, sapling-dotted areas 

 with a decidedly "western" appearance known locally as "blow-sands." 



Ground nests are often merely hollow depressions hned with fine 

 grasses, but those built above the ground can be quite bulky. The 

 cup-shaped structure has a wall of stout grasses and weed stems 

 placed on a foundation of small twigs. Newly cut clover is a favorite 

 building material at Lake Texoma. The nest lining is usually of 

 fine grasses with occasional fine rootlets added. H. T. Gier (1949) 

 reports a nest in Ohio lined with rootlets and hair. 



Nest building at Texoma is not limited to any particular time of 

 day, but activity is at its highest peak early in the morning. On 

 June 26 I watched a female carry material to her nest nine times from 

 5:00 to 5:20 a.m. The nesting material, especially the lining, was 

 gathered from a distance and the birds often flew through the terri- 

 tories of other lark sparrows in their search. One female gathered 

 lining material from a point 200 yards from her nest. 



Territoriality, never strongly marked in this species in Oklahoma, 

 seems to wane as the breeding cycle progresses. During the time of 

 nest building and egg laying both sexes drive other lark sparrows away 

 from the site itself and furiously attack any stuffed lark sparrows 

 placed near the nest. Once incubation is well under way, they 

 tolerate dummies and show no resentment when other lark sparrows 

 wander in the vicinity. Throughout the nesting season the birds 

 gather in small bands as they feed on the lawn and in nearby deserted 

 fields. 



They tolerate other bu'd species on their territories at all times. 

 One lark sparrow started building only 14 inches from an active 

 mockingbird's nest. The lark sparrow was apparently satisfied with 

 the situation, but the mockingbird finally succeeded in driving it from 

 the shrub. I found four examples of lark sparrows and orchard 

 orioles nesting in the same small tree; in one case, in a persimmon, 

 the two nests were only 5 feet apart. One small tree simultaneously 

 contained active nests of a lark sparrow, an orchard oriole, and a 

 scissor-tailed flycatcher. The flycatcher built first, then the sparrow 

 placed her nest 6 feet from the flycatcher's, and finally the oriole built 

 7 feet above the sparrow's nest. No fighting was observed betweeq 

 these birds. 



