184 BIRDS OF THE REPUBLIC OF PANAMA — PART 2 



edge of wing buffy white ; under wing coverts dull cinnamon-buff ; 

 inner webs of secondaries spotted with white. 



Measurements. — Males (2 from Costa Rica and Panama) wing 

 138.0, 138.8; tail 66.1, 67.7 ; culmen from cere 11.8, 12.3 ; tarsus 25.9, 

 26.5 mm. 



Female (1 from Costa Rica), wing 152.0, tail 70.5, culmen from 

 cere 13.8, tarsus 29.8 mm. 



Rare. Known in Panama from 1 specimen, from 2,280 meters ele- 

 vation on the western face of El Baru, Chiriqui. 



This single record, a male, was taken in a mist net on February 17, 

 1965, by E. Tyson. 



Marshall (Condor, 1954, pp. 24-27), in observations in the moun- 

 tains of El Salvador, describes the call of Aegolius ridgwayi as "a 

 series of ten mellow whistles, each note distinct, but not staccato. . . 

 much softer than the whistle of Glaucidhim brasilianum." He 

 observed further that the notes in sound were like those of the 

 northern saw-whet owl, "but were always at a constant pitch." He 

 found a feather in the stomach of one, and a few hairs in another. 



Specific status, and subspecies to be recognized, in this group of 

 owls is uncertain because of the few specimens available. Pending 

 further data the bird of Panama is treated with that of Costa Rica 

 under the name Aegolius ridgzvayi ridgwayi. 



The type of ridgzvayi, a male in the U. S. National Museum, from 

 Costa Rica, with the locality Escazii, in the mountains to the west 

 and southwest of San Jose, and a female in the American Museum of 

 Natural History from Volcan Irazu in that country, are somewhat 

 warmer, brighter brown throughout than the specimen from Chiriqui, 

 but are similar in pattern of coloration, including the restricted mark- 

 ings on the wing. While Alfaro's original description of the type 

 states "toes (except basal half of the outer) naked" it appears that 

 originally they were feathered lightly to beyond the base of the outer 

 joint, as is the condition in the recently taken specimen from Chiriqui. 

 In examination of Alfaro's type under low magnification I note a 

 hint of a few feather papillae along the margin of the area that now 

 is bare. 



The specimen from Volcan Baru in Panama adds one more to the 

 small number of these owls known from the mountain areas of Central 

 America. Like the others, in plumage pattern it resembles the im- 

 mature stage of the northern Aegolius acadicus, from which it differs 

 in absence of light markings on wings and tail. The type specimen 

 of Aegolius ridgwayi rostrata (Griscom) from Guatemala is slightly 



