350 BIRDS OF THE REPUBLIC OF PANAMA PART 4 



on insects, fruit, and nectar. Four males collected by Strauch (Bull. 

 Brit. Orn. Club, 1977, p. 64) weighed from 62.5 to 71.7 g; 5 females 

 weighed from 50.0 to 57.6 g. 



Although while they range in small groups or pairs during the day, 

 at night they tend to gather to sleep in roosts. On the slopes of Cerro 

 Pirre in Darien in late January and early February of 1961, several 

 hundred came to tall trees bordering an open marsh near our camp at 

 450 m elevation on the upper reaches of the Rio Seteganti. Small bands 

 began to arrive after sunset to perch in the high tree crown where they 

 moved about restlessly until finally settled for the night. In the morn- 

 ing they began to call as soon as it was light, and then flew about with 

 noisy wings through the fog-screened treetops until the sun appeared, 

 when they spread out into the adjacent forest. Another roost in early 

 March was located in a band of tall trees along the mouth of the Que- 

 brada Candelaria, in the Province of Panama, where that stream joins 

 the Rio PequenL Here the birds assembled in the forest behind the 

 clearing and came to the roosting area in groups of 25 to 30. These 

 swept in over the tops with much calling and wing noise, rising and 

 falling in undulating lines. 



This species ranges from Nicaragua south through Costa Rica, Pan- 

 ama, Colombia, and Ecuador to northern Peru. Three subspecies are 

 recognized currently, of which 2 (microrhynchus and pacificus) are 

 found in Panama. These differ from the typical race, Cacicus uropy- 

 gialis uropygialis, by their smaller size. The race microrhynchus has 

 often been treated as a separated species, C. microrhynchus, but paci- 

 ficus seems intermediate in bill shape and geographic position. 



CACICUS UROPYGIALIS MICRORHYNCHUS (Sclater and Salvin) 



Cassiculus microrhynchus Sclater and Salvin, Proc. Zool. Soc. London, 1864 (Feb., 

 1865), p. 353 (Lion Hill, Canal Zone.) 



Characters. — Compared with C. u. pacificus, bill, particularly the 

 culmen, more slender, with the mandibular rami normal in form, not 

 swollen laterally; concealed white bases of feathers of dorsal surface 

 found at base of hindneck only, in some specimens absent. 



A male collected at Juan Mina, Canal Zone, on January 14, 1961, 

 had the iris pale blue; bill light yellow at base changing to greenish near 

 center and continuing thus to tip; tarsus and toes fuscous-black. Fe- 

 males I have collected were similar. 



Measurements. — Males (10 from Panama), wing 122.0-136.5 



