FAMILY ICTERIDAE 



36l 



Friedmann (op. ext., 1929, p. 327) describes the eggs as "very light 

 bluish green, bluish, or greenish, and without any markings whatso- 

 ever"; their average measurements are 23 X 18 mm. Tn southern Texas, 

 the incubation period is 12 to 13 days and the young leave the nest at 11 

 days, although they may be fed by their foster parents for another 2 

 weeks. 



MOLOTHRUS BONARIENSIS CABANISII Cassin: Shiny Cowbird, 

 Vaquero Brillante 



Molothrus Cabanisii Cassin, 1866, Proc. Acad. Nat. Sci. Philadelphia, 18, p. 22. 

 (Santa Marta, New Grenada.) 



Medium size; male glossy violet-black; female drab grayish brown. 



Description. — Length, male 227-241 mm, female 196-216 mm. Adult 

 male, body entirely very glossy violet-black; wings and tail more green- 

 ish black. 



Adult female, entire upper surface grayish brown; wings and tail 

 darker dusky brown; undersurface light brownish gray, paler on 

 throat; back and breast more or less finely streaked with dusky. 



Immature, like female but more dusky above, the feathers edged 

 with brownish buff; below more or less yellowish buff; males streaked 

 below with dusky. 



A male collected at El Real, Darien, on February 17, 1964, had the 

 iris dark brown; bill black; tarsus, toes, and claws black. 



Measurements. — Males (10 from Panama and Colombia), wing 

 123.5-135.0 (128.7), tail 97.0-107.2 (102.7), culmen from base 19.5- 

 21.8 (20.9), tarsus 26.6-29.2 (27.9) mm. 



Females (10 from Colombia), wing 98.6-111.5 (107.8), tail 78.5- 

 89.1 (85.9), culmen from base 17.5-19.6 (18.6), tarsus 24.9-26.6 

 (25.4) mm. 



Resident. Rare in eastern Darien and eastern San Bias. W. B. 

 Richardson collected an immature male at Boca de Cupe on the Tuira 

 River, Darien on April 3, 1915 (AMNH no. 136758). On February 

 17, 1964, I shot an adult male from a treetop beside a cattle corral at 

 El Real, Darien, and a few days earlier I saw several along the Tuira 

 River between Boca del Cupe and Yape. In March 1981, Ridgely (in 

 litt.) saw up to 4 per day along the lower Tuira above El Real. From 

 San Bias there is 1 sight report of a group of 7 or 8 birds, including 3 

 or 4 males, seen by D. Sheets east of Puerto Obaldia in June 1965 

 (Ridgely, 1976, p. 309). Ridgely (in litt.) saw 8 on the upper Rio 

 Bayano, Province of Panama, between Aguas Clara and the Rio Diablo 



