170 



BIRDS OF THE REPUBLIC OF PANAMA PART 4 



Two adult males, collected on Cerro Mali, Darien, February 21, 

 1964, had the iris dark brown; edge of eyelid orange-brown; bill, in- 

 side of mouth, and tongue orange; tarsus and toes somewhat paler 

 orange; claws orange-yellow. 



Measurements. — Males (10 from Cerro Mali and Cerro Pirre), 

 wing 86.5-93.2 (88.8), tail 74.2-81.2 (77.5), culmen from base 13.6- 

 15.4 (14.6), tarsus 20.5-23.1 (21.9) mm. 



Females (10 from the same areas), wing 84.4-88.7 (86.8), tail 71.2- 

 78.8 (75.2), culmen from base 13.2-15.3 (14.2), tarsus 20.8-22.8 

 (21.8) mm. 



Resident. Found locally on Cerro Pirre (1500 to 1600 m), Cerro 

 Mali ( 1400 to 1460 m) , Cerro Quia (900 m) , Aturas de Nique, Darien. 



In the latter part of February 1964, these solitaires were fairly com- 

 mon in forest on the slopes of Cerro Tacarcuna, ranging mainly low, 

 concealed in the leaves in the tops of low undergrowth. Generally they 

 remained hidden in this fairly dense cover, so that most of those taken 

 for specimens were captured in mist nets. Rarely, one was seen in the 

 forest. Also rarely, we heard a single note of the song, harsher in 

 sound than that of melanops of the mountains in Chiriqui. 



No nests have been recorded. Young recently from the nest and fully 

 grown birds in juvenile dress were noted in the latter part of May and 

 in June. A female ( AMNH) from "Mt. Tacarcuna, 4600 ft." is labeled 

 "ovary large" on April 16. A full grown molting juvenile (Gorgas 

 Mem. Lab) was taken at Cerro Cana on August 9. 



The species of the genus Myadestes in Panama, obviously of related 

 ancestry, form a highly attractive group. Hellmayr (Cat. Birds Amer., 

 pt. 7, 1934, pp. 440-443) treated them with those of the Andes as geo- 

 graphic races under the name ralloides (described by d'Orbigny from 

 Bolivia) . All are residents of the intermediate and higher elevations in 

 mountain areas, where it may be presumed that their obvious differ- 

 ences may have been established during Pleistocene time. In the pres- 

 ent Recent period those of Panama divide in two isolated groups, sepa- 

 rated in range by considerable spaces of lowland, and here regarded as 

 species. 



The western form melanops of the mountains of Costa Rica and 

 western Panama, with wholly gray body color, black facial mask and 

 yellow bill, is isolated by the broad lowlands of the central isthmus from 

 the eastern coloratus group of the mountains of eastern Darien. These 

 agree with melanops in black mask and yellow bill, but differ completely 

 in wholly brown back. Though this second group is like the forms of 

 the Andes in brown back, it is separated geographically from them by 



