FAMILY ICTERIDAE 



355 



closed, chisel-pointed bill into the bark and then opened the two halves 

 to pry off loose flakes. 



This species is found in pairs all through the year and is rarely seen 

 in groups. Its nest is a cup, not a pendant bag like that of typical 

 Cacicus. Hallinan (Auk, 1924, p. 320) found a nest at Gatun, Canal 

 Zone, on April 24, 1909. It was "in a crotch of a limb in a sparsely- 

 leaved shrub, in the jungle, about 8 feet from the ground. It was closely 

 woven with heavy grass and light twigs and thickly lined with finer 

 grass, with a cavity 2>%. inches in diameter and 2 inches deep. Two 

 eggs, light blue, sparsely spotted with black, denser at the larger end." 

 Another nest, found at Summit, Canal Zone, on September 14, 1941 by 

 Major General G. Ralph Meyer was of similar construction and con- 

 tained two eggs that measured 27.2 X 18.0 and 27.7 X 17.8 mm. In Costa 

 Rica, Skutch (Pac. Coast Avif. no. 31, 1954, p. 284) found fledged 

 young accompanying their parents in early March, indicating a breed- 

 ing season beginning no later than January. A newly hatched nestling 

 he found in May had pink skin with no down, tightly closed eyes, and 

 red mouth lining. 



Eisenmann reports among other calls he has heard this species give 

 in Panama, a clear, emphatic, whistled pur-wee- pew; a rather sweet 

 wrreeeeoo; a harsher kweeyoo; a kwaek-kwack-kwack , sometimes with 

 a buzz in it like kzaak. 



Until recently this species was placed in a monotypic genus Ambly- 

 cercus. 



SCAPHIDURA ORYZIVORA (Gmelin): Giant Cowbird, 

 Vaquero Gigante 



Figure 29 



0.[riolus] oryzivorus Gmelin, 1788, Syst. Nat., 1(1), p. 386. (Cayenne.) 

 Cassidix oryzivora violea Bangs, 1900, Proc. New Eng. Zool. Club, 2, June 30, 



p. 11. (La Concepcion, Santa Marta, Colombia.) 

 Psomocolax oryzivorus impacificus Peters, 1929, Proc. Biol. Soc. Washington, 42, 



p. 123. (Pasa Nueva, Veracruz, Mexico.) 



Large; glossy black with violet sheen. 



Description. — Length, male 305-346 mm, female 270-315 mm. Adult 

 male, entirely glossy black with violaceous sheen. Shows neck ruff in 

 display. 



Adult female, much smaller, entirely black with less gloss and smaller 

 ruffs than male. 



A male collected at Puerto Armuelles, Chiriqui, on March 1, 1966, 



