FAMILY ICTERIDAE 



377 



race was seen by M. Perrone on Barro Colorado Island, Canal Zone, 

 on November 13, 1972 (Ridgely, 1976, p. 311 ). 



XANTHOCEPHALUS XANTHOCEPHALUS (Bonaparte): Yellow- 

 headed Blackbird, Chango Cabeciamarillo 



Icterus xanthocephalus Bonaparte, 1826, Journ. Acad. Nat. Sci. Philadelphia, 5, 

 p. 223. (Along the Loup River, just west of Fullerton, Nance County, Nebraska.) 



Male medium sized, female small for an icterid; male black with yel- 

 low head and throat and white in wing coverts; female dusky brown 

 with white throat and dull orange-yellow breast. 



Description. — Length, male 243-262, female 192-215 mm. Adult 

 male, all black except for rich orange-yellow head (sometimes flecked 

 with black) and breast and extensive white patch on primary coverts; 

 chin, lores, and small area around eye, black. 



Adult female, dusky brown except for facial area and breast; lores, 

 short superciliary stripe, moustachial stripe, and breast dull orange- 

 yellow; throat white, sometimes yellowish; chest slightly streaked with 

 white. 



Immature male, blackish brown except for superciliary stripe, throat, 

 and breast, which are orange-yellow. 



Measurements. — Males (10 from the breeding range, taken in 

 April), wing 137.0-149.0 (144.4), tail 101.8-114.4 (108.3), culmen 

 from base 24.4-26.6 (25.4) , tarsus 34.3-38.5 (36.8) mm. 



Females (10 from the breeding range, taken in May), wing 109.0- 

 119.5 (114.2), tail 78.9-92.9 (84.7) , culmen from base 20.2-22.8 (21.6), 

 tarsus 29.8-32.0 (31.0) mm. 



Casual visitor from the north. The first record of the Yellow-headed 

 Blackbird in Panama is an immature male collected at the Gatun Dam, 

 Canal Zone, on November 1, 1972, by Joseph Strauch. On January 19- 

 26, 1980. at Tocumen Marsh, Canal Zone, up to 8 Yellow-headed Black- 

 birds were seen by various persons, including V. Emanuel, J. J. Pujals, 

 and D. W. Finch; none of these birds was an adult male. In Costa 

 Rica, a flock of 15 to 20 birds, several of which were collected, was seen 

 on February 2-5, 1977 (F. G. Stiles and S. M. Smith, Brenezia, vol. 

 17, 1980, p. 152), so evidently the species is reaching southern Middle 

 America irregularly. The Yellow-headed Blackbird breeds in western 

 North America and winters primarily in the southern United States and 

 Mexico. 



The stomach contents of the bird collected by Strauch included a 

 small grasshopper and other arthropod remains. It weighed 65.5 g 

 (Strauch, Bull. Brit. Orn. Club, 1977, p. 64) . 



