480 BIRDS OF THE REPUBLIC OF PANAMA PART 3 



and Bolivia. The northern bird varies considerably through its wider 

 distribution, so that seven geographic races are recognized in the 

 latest revision (Webster, Auk, 1968, pp. 287-303). Three of these 

 are found in Panama. While Webster suggests placing Mitrephanes 

 in a linear sequence between Contopus and Empidonax , it seems more 

 appropriate here to list it following them, because of the extensive 

 northern range and the migratory habits of the majority of the 

 other two. 



MITREPHANES PHAEOCERCUS AURANTIIVENTRIS 

 (Lawrence) 



Mitrephoriis aurantiiventris Lawrence, Ann. Lye. Nat. Hist. New York, vol. 8, 

 1865, p. 173. (Tabacales, San Jose, Costa Rica.) 



Characters. — Somewhat darker cinnamon-buff on foreneck and 

 breast, with this color, in paler shade, extending over the abdomen, 

 flanks, and under tail coverts ; tarsus slightly longer. 



Measurements. — Males (10 from Chiriqui and Costa Rica), wing 

 58.6-62.7 (60.5), tail 49.0-53.5 (51.3), culmen from base 11.0-12.0 

 (11.6), tarsus 16.0-16.5 (16.2) mm. 



Females (10 from Chiriqui and Costa Rica), wing 56.1-57.4 

 (56.7), tail 46.6-48.9 ,47.6), culmen from base 10.2-11.8 (11.0), 

 tarsus 15.7-16.3 (16.0) mm. 



Resident. Found locally in upper Tropical and Subtropical Zone 

 forests of the mountains of western Chiriqui, from Boquete west 

 through El Volcan and Cerro Punta toward Costa Rica, at about 

 1200 to 2150 meters. 



In the main, these birds range in the undergrowth of humid moun- 

 tain forests, where they are not rare, but are restricted locally in 

 occurrence. Fortunately they are adaptable, as they are able to adjust 

 to the growths that replace the original forest when this has been cut. 

 They may range also in fairly open areas where there are scattered 

 trees in pasturelands. 



The narrowly pointed crest gives them an alert appearance, and 

 identifies them when their colors are not clearly seen. In form and 

 actions in general they are similar to Wood Pewees. It is usual to 

 find them on lookout perches rather near the ground, where they 

 watch alertly for passing insects. These are captured expertly by a 

 dash in the air, when the bird circles to return to its lookout point. 

 The projecting branches of a fallen tree near the ground are favored 

 locations, but also they may range higher, even into the tree crown. 



