FAMILY THRAUPIDAE 



449 



litt. ) found it abundant in the partially cleared lower and middle Tuira 

 Valley, Darien. On the western slope of the Western Andes of Colom- 

 bia it intergrades with nominate flammigerus (Sibley, Proc. Am. Phil. 

 Soc., vol. 102, no. 5, 1958, p. 452), which replaces icteronotus at higher 

 elevations in the Cauca Valley. Preliminary examination reveals that 

 females and immatures from Ecuador are much greener, less brownish 

 or gray, above than are most birds from Colombia and Panama. Thus, 

 it is possible that the Panamanian birds should take the name varians 

 Lafresnaye 1847 (type locality, Buenaventura, Colombia). 



The Yellow-rumped Tanager is often a conspicuous bird in the bushy 

 edges of forest clearings. They are usually seen in pairs or small 

 groups. When resting in the open, they constantly jerk the tail and 

 often twitch their wings; once I saw 1 chase a male Crimson-backed 

 Tanager (R. dimidiatus) . One collected by E. A. Goldman at Porto- 

 belo, Colon, contained the remains of a bettle 10%, and 75 rubiaceous 

 seeds with drupes 90%. Five collected by Burton (Bull. Brit. Orn. 

 Club, 1975, p. 86) and Strauch (Bull. Brit. Orn. Club, 1977, p. 65) 

 weighed from 30 to 35 g. The vocalizations I have heard from this 

 species are a scolding chewp and a note from the female that is exactly 

 like that of the House Sparrow {Passer domesticus) . 



The nesting season runs from at least mid-February, when in 1959 

 I saw 1 gathering nest material at the mouth of the Rio Paya, Darien, 

 until mid-May, when in 1957 Charles Handley found a nest with eggs 

 near the Rio Cangandi, Mandinga, San Bias. In courtship, the male 

 displays before the female by expanding the yellow rump feathers so 

 that the color shows below the line of the wings; at the same time, he 

 frequently turns the back to her and quivers his wings slightly, while 

 the female hops about nervously. Once, I saw 2 males displaying to- 

 gether before 1 female. Although this courtship behavior seems to de- 

 pend on the bold contrast of yellow rump against black body, males still 

 in immature plumage also breed. A nest that I found at the Candelaria 

 Hydrographic Station, Panama, was 2 m from the ground in a small 

 shrub. The nest foundation was of long slender roots of epiphytes, 

 some of them as much as 7 m long, with mixed fragments of dried, 

 dead leaves. On top of this was a deep, open cup made of the same 

 rootlets compactly coiled, also mixed with fragments of dead leaves; 

 the inner lining was of finer, softer rootlets. The nest contained two 

 eggs of light blue, spotted irregularly with black, mainly near the large 

 end; they measured 24.9 X 16.9 and 24.1 X 17.2 mm. A nest found by 

 E. A. Goldman at Lion Hill, Canal Zone, contained three eggs. Other 

 nests found in Panama have been as high as 5 m in trees. 



