CHESTNUT-COLLARED LONGSPUR 1641 



The main building material for the nests seems always to be dried 

 grasses, with animal hair or feathers added to the lining when they are 

 available. Of 33 nests I examined only 3 contained material other 

 than grass — one had seven gray partridge feathers in the lining and the 

 other two each contained one small passerine feather. All these nests 

 were circular in shape except one that was slightly oblong. Seven nest 

 excavations I measured varied from 75 to 100 millimeters (average 88) 

 in diameter, and from 43 to 55 millimeters (average 51) in depth. 

 Nine nests I measured varied from 45 to 70 millimeters (average 60) 

 in inside diameter, and from 38 to 45 millimeters (average 43) in 

 depth of cup. 



The nest is usually well concealed under a clump or tuft of grass. 

 Even when placed in an open spot the nests blend so well with the pale 

 prairie earth they are very hard to see, and the general sameness of the 

 surroundings makes them even more difficult to find. L. J. Moriarty 

 writes (in litt.) : 



A good way of locating the nest, if you don't find it when the female flushes — 

 and she usually walks away from it before flying — is to sit quietly not too far away 

 and watch with binoculars her return. She will not fly directly to the nest, but 

 will alight some distance from it and walk around apparently unconcerned, non- 

 chalantly picking up food. As soon as she is convinced that no danger threatens, 

 she will go to the nest and disappear into it to resume incubating. The nest is 

 usually placed in a tuft of longer grass beside a stone of perhaps baseball size. 

 I believe such sites are selected partly for the shade offered by the grass or rock 

 during the noonday heat, and also because cattle will not step or lie down on 

 stones of this size. 



The female sometimes builds the nest close enough to the boundary 

 of the territory to involve the male in a continual battle with his 

 neighbor. In one such case the two nests were only 130 feet apart. 



Eggs. — The chestnut-collared longspur lays from three to five and 

 sometimes six ovate eggs that may show considerable variability even 

 within a single clutch. The ground is creamy white, spotted, blotched, 

 clouded, and with small scrawls of dark purplish-browns such as 

 "dusky drab," "bone brown," or "olive brown" and black. The 

 undermarkings are often very prominent blotches of "pale neutral 

 gray," or "deep purplish gray." Some eggs have the entire surface 

 clouded with gray undermarkings and with only scattered spots of the 

 purplish-browns and black; others will show considerable ground with 

 the markings concentrated toward the large end where they often 

 form a loose wreath. The measurements of 90 eggs average 18.7 by 



14.2 mm; the eggs showing the four extremes measure 20.8 by 14.7, 



18.3 by 15.9, and 16.2 by 12.7 mm. 



Incubation. — The eggs are laid early in the morning, one each day 

 on successive days until the clutch is complete. At Moose Jaw, 



646-737— 68— pt. 3 26 



