1650 U.S. NATIONAL MUSEUM BULLETIN 23 7 part 3 



larks, cowbirds, and Savannah sparrows. On the other hand I have 

 seen chestnut-collareds being chased by meadowlarks and Baird's 

 sparrows whose nests they probably approached too closely. 



Though a resident of the dry prairies, the chestnut-collar is strongly 

 attracted to water and will visit regularly any that happens to be 

 nearby to drink and bathe. I kept watch at a pool left by recent 

 rains on our study area when the females were incubating their first 

 clutches. Birds visited the pool periodically from a few minutes after 

 sunrise until just before sunset, and their appearances seemed fairly 

 evenly distributed. In 5% hours of watching I never saw two male or 

 two female longspurs at the pool at the same time. One female 

 bathed and preened herself twice over while the male watched im- 

 patiently. After five minutes he finally crowded up to her and chased 

 her back toward the nest, as if urging her to return to the eggs. 



Field marks. — The male in spring with his chestnut collar, black 

 underparts, and white tail can be mistaken for no other species. In 

 other plumages the birds are rather nondescript, and can best be told 

 from the vesper sparrows, pipits, and other longspurs that frequent 

 open ground by the tail pattern. The spread tail is mostly white, with 

 a small dark triangle in the center with its base at the end of the tail. 



Enemies. — By reducing the amount of grassland habitat, man and 

 his agricultural practices are undoubtedly the chestnut-collar's worst 

 enemy. Yet the birds must suffer heavily from the depredations of 

 badgers, skunks, weasels, and snakes, as do all ground-nesting birds. 

 Though as related, the birds will not tolerate Richardson's ground 

 squirrels near their nest, I have no real proof of any predation by these 

 animals. Such nest-robbing birds as crows and magpies must also 

 take their toll. One morning a crow crouched in the grass with just 

 his head showing about 150 feet from a nest with four eggs. The 

 parents investigated him, and then went about their affairs apparently 

 unconcernedly. The crow watched quietly for almost an hour, and 

 then flew off without discovering the nest. Of the 31 nests we had 

 under observation for more than one day, eggs or young disappeared 

 from 11. 



Young birds found dead in the nest are usually covered with ants. 

 Though this is no proof that they caused the deaths, the female may 

 often be seen cleaning ants out of the nest and picking them off the 

 nestlings. 



Hawks, owls, and shrikes also take a few birds without doubt, 

 though the only record in the literature is M. F. Gilman's (1910) 

 report of a Cooper's hawk preying on a flock in Arizona. 



Cases of cowbird parasitism are rare. None of the 36 chestnut- 

 collared nests we found in Saskatchewan was parasitized, though 

 three of the four lark-bunting nests we found in the same area con- 



