322 



BIRDS OF THE REPUBLIC OF PANAMA PART 4 



edged olive-green; chin, sides of throat, and side of face to auriculars 

 white; sides of breast, sides, and flanks olive-yellow; rest of under- 

 surface yellow. 



The Rufous-capped Warbler is found from northern Mexico 

 through Central America to northern Colombia and western Venezuela. 

 In Panama the race mesochrysus is common in lowlands of the Pacific 

 slope and on the Caribbean slope in the vicinity of the Canal Zone. 

 Another race, actuosus, inhabits Isla Coiba off the Pacific Coast of 

 Veraguas. The forms ranging from southeastern Guatemala south- 

 ward through Middle America to Colombia and Venezuela (including 

 all Panama populations) are often separated as a distinct species, B. de- 

 latrii (see Todd, Proc. U.S. Nat. Mus. 74, art. 7, 1929, pp. 85-87; Hell- 

 mayr, Field Mus. Nat. Hist. Zool., vol. 13, pt. 8, 1935, pp. 508-512). 



The habitat of this species is scrubby clearings, weedy fields, and 

 second growth. It usually forages near the ground, where its secretive 

 behavior makes it hard to see, but once at Pese, Herrera, I watched 1 

 come up to feed actively in leafless branches 10 m above a stream. 

 Skutch, who has observed this species in Costa Rica (Publ. Nutt. Orn. 

 Club, no. 7, 1967, pp. 159-164) noted that it usually travels in pairs. 

 Males sing from February to August and may deliver their song from 

 elevated perches at dawn, but sing from within thick shrubbery during 

 the rest of the day. Eisenmann (Smiths. Misc. Coll., vol. 117, no. 5, 

 1952, p. 53) describes the song as heard at Playa Coronado in June, as 

 "a rather rapid, dry, chittering chit-cha-chup-cha-chuweep, with vari- 

 ations. . . . calls include a simple chit, a zeep-zeep or dzit-dzit." Some- 

 times the song ends with a chee-weecha. In central Panama, Eisenmann 

 has noted singing from early March through late June. 



E. A. Goldman collected 2 specimens with full stomachs at Corozal 

 in the Canal Zone on June 15, 1911: one contained a chrysomelid 3%, 

 a small curculionid 2%, elaterid fragments 3%, bug remains 3%, many 

 fulgorid remains finely ground 44%, more than four large ants 35%, 2 

 smaller species 8%, other coleoptera 2%; the other contained 5 ants 

 44%, a reduviid 15%, Achalles sp. 10%, 2 cerambycids 15%, a riti- 

 dulid near Colastus 8%, other coleoptera fragments (Chrysomelidae) 

 8%. 



BASILEUTERUS RUFIFRONS MESOCHRYSUS Sclater 



Basileuterus mesochrysus P.L. Sclater, 1861, Proc. Zool. Soc. London, 28 (1860), 

 p. 251. ("Bogota," Colombia.) 



Characters. — Undersurface brighter yellow than in B. r. actuosus; 

 gray of nape lighter. 



