568 BIRDS OF THE REPUBLIC OF PANAMA PART 3 



CAMPTOSTOMA OBSOLETUM FLAVIVENTRE 

 Sclater and Salvin 



Camptostoma flavivcntre Sclater and Salvin, Proc. Zool. Soc. London, 1864 

 (February 1865), p. 358. (Lion Hill, Canal Zone, Panama.) 



Characters. — Paler above, with crown cap browner ; more distinctly 

 yellow on the lower surface. 



A male in breeding condition, taken at Aguadulce, Code, January 

 17, 1963, had the iris brown; maxilla dull black; lower side of base 

 of mandible dull brown ; rest of mandible fuscous ; tarsus dusky 

 neutral gray ; toes, including the claws, black. Others that I have 

 examined have had the maxilla and tip of the mandible dull fuscous; 

 base of the mandible brownish white. The gape and inside of the 

 mouth are reddish orange. 



Measurements. — Males (10 from Herrera, Los Santos, Canal Zone, 

 and Province of Panama), wing 50.3-54.6 (51.9), tail 34.6-41.4 

 (39.0),culmen from base 9.1-10.8 (9.8), tarsus 13.3-15.2 (14.0) mm. 



Females (10 from Chiriqui, Los Santos, Herrera, Canal Zone, and 

 Province of Panama), wing 45.3-50.1 (48.1), tail 33.3-35.2 (34.7), 

 culmen from base 9.1-9.9 (9.4), tarsus 13.0-15.7 (14.1) mm. 



Resident. Locally common in the Tropical Zone ; Pacific slope from 

 Costa Rica eastward, including Herrera and Los Santos on the 

 eastern side of the Azuero Peninsula, eastern Province of Panama 

 (Chepo), and Darien ; Carribbean slope in the lower Chagres Valley 

 (Pitia, Lion Hill, Gatun, Barro Colorado Island, Juan Mina) and 

 adjacent eastern Colon; eastern San Bias (Perme, Puerto Obaldia) ; 

 Isla Cebaco in Golfo de Montijo. 



These tiny flycatchers are common in the tropical lowlands of the 

 Pacific slope east to the lower Rio Bayano, and range north also 

 across the lowland divide where the Panama Canal crosses to the 

 north coast near Colon. The most western record on the Caribbean 

 side is a male taken by S. Olson at Pina. There are records for 

 Darien from Garachine, Santa Fe (on the Rio Sabana), and El Real, 

 with one at Cana on Cerro Pirre. It is probable that they are found 

 in small numbers through the Tuira basin. And it is also probable 

 that they range through the lowlands of San Bias, though the only 

 records are from near the Colombian boundary at Perme and Puerto 

 Obaldia. 



Along the Pacific slope they are found through the thickets and low 

 tree growth of the savanna area, sometimes low, near the ground, 

 sometimes higher in the trees. While at times they move rather 

 quickly so that they seem as active as wood warblers, it is more 

 usual for them to show the quieter movements common to many 



