FAMILY TYRANNIDAE 55 1 



guas at Chitra, and in the Azuero Peninsula on Cerro Montuosa, on 

 the boundary between Herrera and Veraguas. Reported to 3300 

 meters on the summit of the volcano, common to 2500 meters. 



As the name impHes, this is a true mountain species found from 

 the upper margin of the Tropical Zone at 1250 meters through the 

 Subtropical Zone to Temperate Zone elevations above 3000 meters on 

 the slopes of Volcan Baru. In this range it is most abundant above 

 1500 meters. It is found regularly in the tops of trees in the forests 

 where often it is quiet and remains hidden among the leaves. It 

 ranges regularly also in the scattered shrubbery and lines of bushes 

 and low trees of open meadows and is there more easily seen. Where 

 food is abundant in the form of insects or berries these birds may be 

 seen in group association, though they are not social ; they range as 

 single birds and usually they are belligerent toward others of their 

 kind. 



Low call notes are heard from them regularly, usually a slightly 

 prolonged pee-ee-er, varied somewhat in depth of sound. Skutch 

 records them singing a rather monotonous repetition of a single 

 syllable. While regular in early morning, this was continued also on 

 occasion into the middle of the day. They also have rattling, twitter- 

 ing calls. 



Like Eisenmann and other observers I have found this species most 

 common from the Llanos del Volcan to the slopes near and above 

 Cerro Punta, where often dozens have congregated because of the 

 abundant berry-bearing trees and bushes. 



Blake (Condor, 1956, p. 387) described three nests collected by 

 T. B. Monniche on the Finca Lerida above Boquete, in April and 

 May. All, placed low down in coffee trees, were open cups made of 

 rootlets covered with moss and lined with horse hairs and a few 

 feathers. The average size was about 90 by 50 mm, with the cup about 

 65 mm in diameter by 20 mm deep. The two eggs in each were "dull 

 white marked, chiefly on the larger end, with a few reddish-brown 

 spots and dots. Measurements of three eggs: 21.3 X 16.5, 18.5 X 14.9, 

 18.8x15 mm." 



In observations in Costa Rica Skutch (Publ. Nuttall Orn. Club 7. 

 1967, pp. 97-99) recorded that nest building and incubation were 

 the function of the female, with the male assisting later in feeding the 

 young. The set in 11 nests was two eggs which ranged "from dull 

 white to pale buff in ground color, marked with spots and blotches of 

 pale cinnamon, rusty brown, or chocolate, which usually formed a 

 wreath around the broad end and are thinly scattered elsewhere. In 



