474 



BIRDS OF THE REPUBLIC OF PANAMA PART 4 



A male collected at the head of the Rio Guabal, Code, on February 

 26, 1962, had the iris bright reddish brown; base of mandible greenish 

 gray; rest of bill, tarsus, toes, and claws black. A female taken there 

 2 days later had the iris dull reddish brown and the bill entirely black. 



Measurements. — Males (10 from Panama), wing 73.0-76.5 (74.5), 

 tail 63.3-66.8 (65.0), culmen from base 14.9-16.2 (15.5), tarsus 17.8- 

 19.6 (18.8) mm. 



Females (10 from Panama and Costa Rica), wing 65.0-69.5 (66.8), 

 tail 54.6-65.2 (59.8), culmen from base 13.4-15.4 (14.4), tarsus 17.1- 

 19.2 (18.2) mm. 



Resident. Locally common in the lowlands on the Caribbean slope; 

 on the Pacific slope it has been found in the foothills of Veraguas at 

 Santa Fe by Arce in the 1860's and by Ridgely and F. G. Stiles in the 

 1970's (Ridgely, 1976, p. 325), and in Darien. In eastern Province of 

 Panama, Eisenmann and J. Pujals found this species "surprisingly 

 common" on the El Llano-Carti road on March 28-29, 1975; there is 

 also a male specimen in the Gorgas Memorial Laboratory collected by 

 R. Hinds at Saino Madronio in the Bayano River Valley. Beyond Pan- 

 ama, it ranges from Nicaragua to northwestern Ecuador. 



This species inhabits humid forest and forest borders, where I have 

 seen it everywhere from low growth to the tree crown, but usually in 

 lower and middle levels. It customarily moves about actively in groups 

 of 6 to 20, sometimes joined by other species. The male presents a 

 striking appearance when raising the dark orange feathers of the cen- 

 tral crown. As they move about, these tanagers constantly utter sharp 

 squeaking notes. A bird that E. A. Goldman collected contained bits of 

 elytra of a beetle 4% and fragments of 25 ants of two species 96%. 

 None that I collected showed any signs of breeding, and I know of no 

 published information on this subject. Ridgely {in litt.) saw a female 

 carrying nesting material on the Pipeline Road, Canal Zone, on April 

 3, 1976. 



HETEROSPINGUS XANTHOPYGIUS (Sclater): Sulphur-rumped 

 Tanager, Frutero Hormiguero Cejiescarlata 



Medium size; bill hooked at tip; male of nominate race black, with 

 stripe over eye white, becoming red, and patches of bright yellow on 

 lower back and lesser wing coverts; female of nominate race and both 

 sexes of H. x. rubrifrons entirely gray, darker on upper surface, with 

 bright yellow lower back. 



Description. — Length 150-168 mm. Adult male of nominate race, 

 thin stripe over eye, beginning beyond lores, white, becoming broader, 



