FAMILY TINAMIDAE II 



Characters. — Crown chestnut to chestnut-brown; dorsal surface 

 paler. 



Measurements. — Males (10 specimens from Costa Rica and 

 Chiriqui), wing 219-232 (227.4), culmen from base 30.8-36.6 (34.4), 

 tarsus 65.4-70.8 (67.7), middle toe with claw (8 specimens) 34,2-40.2 

 (37.5) mm. 



Females (8 specimens from Costa Rica and Chiriqui), wing 221- 

 240 (233), culmen from base 31.7-38.8 (35.6), tarsus 67.4-76.5 

 (71.3), middle toe with claw (6 specimens) 38.0-40.9 (39.4) mm. 



Resident. In forests on the Pacific slope from western Chiriqui 

 through central Veraguas and western Province of Panama to the 

 Canal Zone, extending into the lower part of the Subtropical Zone to 

 1,500 meters elevation in Chiriqui (Santa Clara, El Volcan). The 

 extralimital range extends along the Pacific slope west to central 

 Costa Rica (Puntarenas, Rio Pirrls). 



Intergradation with the subspecies T. m. saturatus begins near the 

 original continental divide in the Canal Zone, as is shown by an adult 

 male from Barro Colorado Island that has the feathers of the back 

 of the crown very slightly elongated. Though this appears to be a 

 hint of the nuchal crest that marks saturatus, the coloration is that 

 of castaneiceps. 



Van Tyne (Occ. Pap. Mus. Zool. Univ. Michigan, 1950, pp. 2-4) 

 gives the following data from 2 nests, one of 4 and one of 6 eggs, 

 found on Barro Colorado Island: Size, 56x45 mm. to 62x50 mm.; 

 weight 56.0 to 81.4 grams. He described the color as beryl green. 



In examining other races of this tinamou from northern South 

 America one is aware immediately of the close resemblance of 

 castaneiceps to T. m. zuliensis, the form that is found from the 

 lower Rio Sinu Valley in Colombia eastward through the Santa 

 Marta region to eastern and southern Venezuela. The principal 

 characters of difference that mark castaneiceps are the somewhat 

 duller reddish brown of the crown, the more buffy, less reddish brown 

 of the hindneck and the sides of the head, and the average darker 

 coloration of the upper surface. In considering the evident close 

 resemblance one has the definite impression that castaneiceps and 

 suliensis of today represent the descendants of one stock found for- 

 merly throughout the tropical lowland areas from Panama to Vene- 

 zuela that has been divided by the intrusion of the much darker 

 saturatus, an intrusion permitted through environmental change 

 occasioned by the heavier annual rainfall found in the range of the 

 darker form. 



