FAMILY THRAUPIDAE 



485 



from El Uracillo, Code, on the Rio Indio, in the Canal Zone, and the 

 Rio Piedras in eastern Colon. In the Chiriqui highlands, W. W. Brown, 

 Jr., collected it as high as 1050 m at Boquete ( Bangs, Proc. New Eng- 

 land Zool. Club, vol. 3, 1902, p. 60), and I collected 1 near there at 1200 

 m on El Salto, March 16, 1960. This race also occurs in southwestern 

 Costa Rica; others are found in western Mexico and in northern Co- 

 lombia and northern Venezuela. 



The thrush-tanager inhabits dense thickets and undergrowth in 

 woodland and shrubby clearings. It feeds on or near the ground and 

 is often almost impossible to see even when calling from only a few 

 meters away; several times I found males with their brightly-colored 

 breasts turned away from me. When on the ground, the thrush-tanager 

 uses its long, slender bill to pick and toss aside leaves, under which it 

 finds food. The stomach of 1 collected by E. A. Goldman contained 3 

 Acalles sp. fragments 20%, a small carabid 2%, 2 spiders 5%, other 

 coleopteran remains (cerambycid ?) 13%, pentatomid remains 5%, ant 

 remains 5%, all animal matter very finely comminuted, 5 shelled seeds 

 of Ichnanthus sp. and 12 entire seeds of a small Panicum 4%, about 

 85 seeds of Carduaceae, perhaps Helianthus sp. 42%, vegetable rub- 

 bish 4%, frog bone trace. A male collected by Strauch ( Bull. Brit. 

 Orn. Club, 1977, p. 65) weighed 51.8 g. 



This species remains paired throughout the year, and both sexes use 

 a wide variety of vocalizations to communicate with their mate through 

 the dense habitat, in which it may be invisible. The songs are a succes- 

 sion of loud phrases suggestive of the calls of wrens in the genus 

 Thryothorus; one has been rendered as wheeo-cheehoh, chweeoo 

 (Ridgely, 1976, p. 236). The thrush-tanager is a persistent singer; I 

 know of no other tanagers in which members of a pair sing antiph- 

 onally. Sometimes it sings in rather unexpected circumstances, as 

 when being held in the hand after removal from a mist net. 



In the Canal Zone, Goldman found a pair breeding on May 9, 1911, 

 and Major General G. Ralph Meyer discovered a nest with fresh eggs 

 on July 16, 1941. The nest was a cup built of twigs like that of a 

 North American Cardinal (Cardinalis cardinalis) , lined with a pad of 

 black horsehairlike vegetable fiber, like that used in the nest of ant- 

 tanagers (Habia); this material is the rootlet of a plant that seems to 

 be parasitic on dead branches of trees. The diameter of the nest was 

 15 by 7.5 cm and the depth was 10 by 3 cm. The nest contained two 

 eggs. Skutch (Auk, 1962, pp. 633-639), who has studied this bird in 

 Costa Rica, found parents accompanied by young juveniles in the mid- 

 dle of February and found another pair building a nest in April. Both 



