214 BIRDS OF THE REPUBLIC OF PANAMA PART 4 



1500 m, and Blake (Fieldiana: ZooL, vol. 36, no. 5, 1958, p. 553) men- 

 tions a male collected April 4, 1933, at Lerida (1650 m). Griscom's 

 comments — "decidely uncommon winter visitant" (Bull. Mus. Comp. 

 ZooL, vol. 78, 1935, p. 364) and "few records south of western Pan- 

 ama" ( Amer. Mus. Nov. no. 282, 1927, p. 7) — do not seem accurate on 

 the basis of more recent collecting and observation. Ridgely (1976, p. 

 284) gives dates of occurrence from late October to early April. F. S. 

 Blanton collected 2 males at Albrook Field in the Canal Zone on Oc- 

 tober 22, 1953, and the latest spring occurrence of which I know is the 

 April 4 bird from Chiriqui mentioned above. 



As a migrant and winter visitant in Panama the Yellow-throated 

 Vireo's habits are essentially the same as in their breeding areas to the 

 north. They are slow moving even for a vireo, although they sometimes 

 join groups of warblers moving through the trees. Willis (Living 

 Bird, 1966, p. 205-206) observed 1 foraging near the ground on Barro 

 Colorado Island on December 17, 1960, that ignored a nearby active 

 swarm of army ants; he remarked that on Barro Colorado this vireo is 

 usually found in the treetops. I have found them in mangrove swamps 

 on San Jose, Pearl Islands, in open woodland along a quebrada in Ja- 

 que, Darien, and in shade trees over coffee at Santa Clara (1260 m), 

 Chiriqui. At this season they take fruit as well as insects; 1 I shot on 

 Isla Parida, Chiriqui, had the stomach filled with two good-sized drupes. 



Molt begins by January. A female I collected January 25, 1962, at 

 Las Palmitas, Los Santos, was molting around the head; the incoming 

 new feathers on the throat appeared very orange. A bird collected at 

 the head of the Rio Guabal, in Code, on February 28 that year was in 

 molt and had not developed body fat; another bird collected February 

 28, 1965, at El Volcan, Chiriqui, also had no fat forming. Two birds 

 that had just completed a molt and had no fat were collected at Santa 

 Clara, Chiriqui, on March 17, 1954. I have collected specimens with 

 heavy body fat on March 6, at El Potrero, Code, and March 17, at El 

 Volcan. Ridgely (op. cit.) says its song is "Quite often heard, espe- 

 cially in spring." Eisenmann (in litt.) notes that this species gives a 

 nasal snarl and a fast chittittittity, vocalizations also heard on the breed- 

 ing grounds. 



[VIREO SOLITARIUS (Wilson): Solitary Vireo, Vireo Solitario 



Muscicapa solitaria Wilson, 1810, Amer. Ornith., 2, p. 143, pi. 17, fig. 6. (Bartram's 

 Woods, near Philadelphia, Pennsylvania.) 



Vagrant. This species is included on the basis of three recent sight 

 reports. At El Volcan in western Chiriqui, 1 was seen on March 17, 



