EASTERN AND CANADIAN CHIPPING SPARROWS 1179 



of 66 "Walkinsbaw (1944b) found in southwestern Michigan only three 

 were parasitized. Sutton (1960) reports that on the George Reserve 

 in southern Michigan he found only 1 of 38 nests with a cowbu'd egg 

 in it, and although he saw one 3^oung cowbird out of the nest being 

 fed by a chipping sparrow, he did not find a nest containing a young 

 cowbird. He attributes the low parasitism to the fact that in the 

 red cedars of the George Reserve the nests are very well concealed. 

 The success of the cowbirds in cliipping sparrow nests seems to be low. 



About 60 percent of chipping sparrow nests are successful (Walkin- 

 sbaw, 1944b, 1952) and the failures may be attributed to many 

 different factors of which predation is only one. Snakes (Sutton, 

 1960), bu-ds (Dixon, 1930), and cats (Walkinshaw, 1944b) have been 

 observed preying on eggs or 3^oung, Maurice Broun wTites me from 

 Hawk Mountain, Pa., that "Our chipping sparrows are often victims 

 of predation by the black and milk snakes. We have noted that 

 when first nestings fail, the birds usually build their second nest at 

 higher elevations." 



Chipping sparrows are subject to a number of external parasites. 

 H. S. Peters (1933) lists the follo\nng parasites collected from birds 

 during banding: two species of lice {Philopterus subfiavescues (Geof.), 

 Ricinus sp.) ; two species of flies (Ornithoics covfiueus Say, Ornithomyia 

 aviciilarm Linn) ; one species of tick {Ixodes brunneus Koch) ; and two 

 species of mites {Analgopsis sp., Liponipsus sylviarum). 



A foot disease, often called "foot-pox," is common in chipping 

 sparrows in the southeast in late winter and early spring. At Sum- 

 merville, S.C., 13.6 percent of the 323 WOliam P. Warton banded in 

 1929 (Warton, 1931) were afflicted, while another 9.3 percent showed 

 evidence that they had recovered from the disease. In 1930 the 

 disease was less prevalent, active in only 5.09 percent of the 255 birds 

 Warton banded that year. Robert A. Norris, while banding a smaller 

 sample, found a much higher incidence in 34 adults and first-winter 

 bh-ds trapped near Tifton, Ga., from Feb. 29 thi-ough Mar. 24, 1952. 

 He reports (Norris, 1952) "Twenty seven bu-ds or about 82%, includ- 

 ing both age groups, were afflicted with foot-pox {epithelioma con- 

 tagiosum), having discolored tumors on one or more toes and occasion- 

 ally at the end of the tarsus. Some had lost a claw or two, and some 

 parts of toes * * *. 1952 appears to be a peak year for this disease 

 * * *. The overall average weight of 12.5 grams is very close to 

 that of April trapped, non-diseased birds from Cleveland, Ohio 

 (Baldwin and Kendeigh, Auk, 55:436, 1938). Both this fact and the 

 data from Tifton suggest that, in general, diseased Chipping Sparrows 

 weigh about the same as non-diseased ones." 



Fall. — After nesting the family groups wander about feeding, usu- 

 ally in weedy fields, along fence rows and forest edges where they 



