1316 U.S. NATIONAL MUSEUM BULLETIN 23 7 part 3 



predator. I saw red foxes nearby, however, and noticed the strong 

 scent of fox near one Gambel's sparrow nest from which nestlings 

 disappeared several days before they were due to be fledged. 



As white-crowned sparrows live near human habitation, cats must 

 be considered as enemies. They often interfere with banding opera- 

 tions by developing the habit of visiting the traps. One such case is 

 interesting because of the reaction of the victim. As I was inspecting 

 my traps I came upon a cat crouched beside one of them. It had badly 

 mauled a Gambel's sparrow inside the trap. The bird was bleeding, 

 some of its feathers were scattered on the ground, and it gave every 

 sign of terror. I chased the cat away, banded and released the bird, 

 and reset the trap. Less than 20 minutes later the same bird re- 

 entered the trap. 



There are two records of white-crowned sparrow nests parasitized 

 by cowbirds. Henry J. Rust (1917) found a nest with five eggs, in- 

 cluding one egg of a cowbird, along Little Dry Creek in Fremont 

 County, Idaho. Friedmann (1938) describes a nest in the Royal 

 Ontario Museum at Toronto collected at Okotoks, Alberta, that con- 

 tains one white-crowned sparrow egg and two eggs of the cowbird. 



I have frequently found nematode worms in the body cavity of 

 sparrows collected in or near Santa Barbara. Rarely I have found 

 parasitic flies of the genus Ornithoica clinging to the feathers of trapped 

 birds. Otto E. Plath (1919) found 36 full-grown larvae of Proto- 

 calliphora azurea (Fallen), (now placed in the genus Phormia) in the 

 nest of a NuttalTs sparrow in the San Francisco Bay Region. They 

 were determined to be sucking the blood of nestlings; some died as the 

 result, others were retarded in growth. C. M. Herman, H. A. Jan- 

 kiewicz and R. W. Saarni (1942) found protozoan parasites of the 

 genus Isospora in one Gambel's sparrow. 



In the category of accidents should be mentioned the occasional 

 sparrow that kills itself by flying against a window. Alfred B. Howell 

 (1914) reports seven Gambel's sparrows destroyed in an orange grove 

 in Covina, Calif., when the trees were fumigated with hydrocyanic 

 acid gas. Frank S. Daggett (1902) reported three Gambel's sparrows 

 found dead on the surface of cyanide tanks at a gold mining camp in 

 the Cargo Murchacho Mountains west of Yuma on the Colorado 

 desert. On the whole, however, the effects of man's activities are 

 usually beneficial to white-crowned sparrows. Roadbuilding and 

 clearing allows them to extend their range into areas formerly too 

 densely wooded for them. 



The mortality rates for nestlings I followed are highest for Berkeley 

 NuttalTs sparrows, lower for Friday Harbor Puget Sound sparrows, 

 and lowest for Alaska Gambel's sparrows. Of 30 broods of NuttalTs 

 sparrows I watched, only 12, or 40 percent, were successfully fledged. 



