CLAY-COLORED SPARROW 1203 



Field mar^5.— Breeding plumage: The clay-colored sparrow is 

 slightly smaller and paler than the chipping sparrow. Five head 

 characters are important in field identification: (1) a median cro^^^l 

 stripe of pale gray or biiffy; (2) brown ear patches outlined with black 

 lines; (3) a prominent white malar stripe on each side of the throat; 

 (4) a hght supercihary stripe; (5) a gray nuchal collar extending to 

 the sides of the neck. 



Fall and winter plumage: Adidts may lack one or more of the head 

 characters, especially the crown stripe. Field identification in first 

 winter plumage with absolute certainty is sometimes impossible, 

 because of the general similarity to the first winter plumages of chip- 

 ping and Brewer's sparrows. 



Enemies. — During the nesting stage clay-colored sparrows are most 

 vulnerable when nests are close to the ground or in areas of high nest 

 concentration. Stuart Criddle, veteran Manitoban field naturalist, 

 has provided the following list of mammals that may be considered 

 predators of the eggs and young of S. pallida: Drummond's vole, 

 Microtus jpennsylvanicus drummondii; Baird's white-footed mouse, 

 Peromyscus maniculatus hairdii; short-tailed ermine, Aiustela erminea 

 bangsi; prairie long-tailed weasel, Mustela frenata longicaiula; least 

 weasel, Mustela r. rixosa; northern plains skunk. Mephitis m. hudsonica. 

 Other sources of destruction are garter snakes, loggerhead shrikes, 

 black-billed magpies, fire, and trampling by cattle and horses. 



Severe weather is a serious menace to eggs and young. G. C. 

 Kuyava informs me from Duluth that three storms totaling over 7 

 inches of rainfall in 2 weeks commencing June 30, 1958, destroyed 14 

 of the 17 nests under observation. 



The clay-colored sparrow is a common victim of the cowbird. I 

 have records of imposition in British Columbia, Alberta, Saskatche- 

 wan, Manitoba, Ontario, Montana, North Dakota, Minnesota, Michi- 

 gan, and Wisconsin. According to Herbert Friedmann (1963) 

 S. pallida is frequently victimized in Alberta. In Saskatchewan, 

 Fox (1961) in one season found eight of nine nests parasitized. None 

 of the 10 cowbird eggs hatched. In 6 nests the cowbird's eggs were 

 laid when the sparrow eggs were fresh, but no sparrows hatched from 

 any of these six nests. In the seventh nest a cowbird egg was laid 

 after four j^oung sparrows had hatched. In the eighth, a replacement 

 nest, three cowbird eggs were laid before completion of the nest. 



The cowbird frequently parasitizes the clay-colored sparrow in 

 Manitoba. Mr. and Mrs. John Lane sent the following report on 

 31 nests near Brandon in 1960: 



"Twenty, all near heavy tree cover, contained eggs of Molothrus 

 ater, while 11, all well away from heavy cover, were unparasitized; 

 14 held one egg, 4 held two eggs, and 2 held three cowbird eggs. Of 



646-737— 68— pt. 2 10 



