FAMILY ANAXroAE 



151 



black line through the eye, and another on the side of the head from 

 the gape back over the ear coverts ; breast and sides mottled with 

 black ; a prominent white wing patch. 



Immature male resembles the female but is more extensively black 

 on the crown. 



Measurements. — Males (5 from Panama), wing 136.2-138.0 

 (137.2), tail 75.2-79.0 (77.1), culmen from base 31.1-33.9 (32.0), 

 tarsus 26.1-27.6 (27.0) mm. 



Fig. 29. — Masked duck, pato tigre, Oxyura dominica, male. 



Females (5 from Mexico, Panama, and Venezuela), wing 132.0- 

 139.0 (136.4), tail 74.0-79.2 (76.5, average of 4), tarsus 25.7-27.9 

 (26.9) mm. 



An adult male, taken December 12, 1955, had the iris reddish 

 brown ; base of the maxilla light blue, shading to light greenish blue 

 toward the tip; nail, space immediately behind, and culmen, to and 

 including the nostrils, and a few irregular, scattered spots over the 

 rest of the bill, black ; tip of mandible flesh color ; mandibular rami 

 pale grayish blue, with a line on either side of the tip, spots toward 

 the base, and the bare skin between, black; tarsi and toes, including 

 the nails, greenish olive-brown. 



Resident. In the tropical zone in suitable fresh waters ; locally 

 fairly common. 



