l6o BIRDS OF THE REPUBLIC OF PANAMA PART 4 



in and bordering forest from about 1500 to 2250 m. The song is liquid 

 and long-continued, far-ranging, but not nearly so loud as those of the 

 local solitaire. One of the frequent phrases can be syllabized as dleedle- 

 edleeyee. The song is reminiscent of that of the northern Hermit 

 Thrush, the effect melancholy, the quality liquid, but rather throaty; the 

 phrases are deliberate with pauses of 2 to 3 seconds between them, and 

 the song so long continued that over a hundred phrases may be given 

 before there is a rest of more than a very few seconds. Dr. C. Hart- 

 shorne, in lift, to Eisenmann, characterized the song very well as hav- 

 ing phrase structure close to that of the northern Wood Thrush, but 

 tone quality closer to that of the Hermit Thrush. 



CATHARUS AURANTIIROSTRIS (Hartlaub): Orange-billed Nightingale- 

 Thrush, Zorzal Pico Anaranjado 



Turdus aurontiirostris Hartlaub, Rev. Mag. Zool., March 1850, p. 158. (Caracas, 

 Venezuela.) 



Rather small; crown gray; rest of dorsal surface rufescent brown, 

 breast gray, rest of undersurface white. 



Description. — Length 132-158 mm. Adult (sexes alike), crown 

 gray; rest of dorsal surface, including wings and tail, rufescent brown; 

 upper breast and sides gray; throat white, streaked with gray; lower 

 breast, abdomen, and undertail coverts white. 



Immature, back and, to a lesser degree, the crown dull dark brown 

 with the feathers tipped irregularly with black; breast and sides dull, 

 faintly buffy white, with the feathers tipped and edged with dull black; 

 undertail coverts buffy brown; bill black. 



Widely distributed as a species from northern Mexico through 

 Central America and northern South America, in Colombia, Venezuela, 

 and the island of Trinidad. Several forms are recognized, two of them 

 found in Panama. (For notes on this species see Zimmer, Auk, 1944, 

 pp. 404-408.) The gray-crowned populations of southwestern Costa 

 Rica, Panama, and western Colombia were formerly regarded as a 

 separate species, C. griseiceps. 



Ridgely (1976, p. 278) describes the song as "poor and unmusical 

 with varied phrases, some twangy, others squeaky; a short tsip, wee-ee, 

 tsirrip-tsip is one of several." 



This species tends to range lower in the highlands of Panama than 

 the other species of Catharus and is the most widely distributed, favor- 

 ing clearings and second growth. 



