336 



BIRDS OF THE REPUBLIC OF PANAMA PART 4 



uralist in Costa Rica, 1971, p. 103) has heard them singing in winter. 

 During the winter their distribution is more erratic and they are usually 

 found in smaller groups, in clearings and marshes where they feed on 

 seeds. Country people often call these birds "veinticuatro" from their 

 habit of ranging in little flocks that popularly are believed always to 

 number 24 individuals. A Dickcissel killed in an October rainstorm at 

 Almirante weighed 24.36 g and had enough fat to travel another 846 

 km (Rogers, Bird-Banding, 1965, p. 116). 



PSAROCOLIUS MONTEZUMA (Lesson): Montezuma Oropendola, 

 Chacarero de Montezuma 



Figure 27 



Cacicus Montezuma Lesson, 1830, Cent. Zool., livr. 2, p. 33, pi. 7. (Mexico.) 



Very large; narrow crest, head, upper back, throat, and breast black; 

 wings and rest of body chestnut; central pair of tail feathers dark 

 brown, others bright yellow; particolored bill. 



Description. — Length, male 395-475 mm, female 347-398 mm. Adult 

 male, head, nape, upper back, throat, and breast black; rest of upper 

 surface, including wing coverts, chestnut; primaries blackish, with 

 basal half of outer web of eighth primary chestnut, and chestnut in- 

 creasingly extensive on outer web of inner primaries; secondaries 

 chestnut on outer web, blackish on inner web, increasingly reduced to- 

 ward inner secondaries; central rectrices blackish, shorter than others, 

 which are bright yellow; sides, flanks, and abdomen chestnut; central 

 undersurface black with feathers tipped chestnut; underwing coverts 

 black. The basal half of the bill is black, the terminal half is orange; a 

 bare frontal shield is blackish; patch of bare skin below eye bluish and 

 pink. 



Adult female, like male, but smaller and black more brownish on 

 breast and rest of undersurface. 



Immature, like adult, but brown areas are duller; bill dusky at base, 

 less yellow at tip. 



Measurements. — Males (10 from Panama, Costa Rica, Guatemala, 

 Honduras, and Nicaragua) , wing 218.8-261.0 (236.7), tail 170.9-200.2 

 (181.6), culmen from base 71.5-81.1 (74.4, average of 9), tarsus 52.4- 

 56.9 (54.5) mm. 



Females (10 from Panama, Costa Rica, Guatemala, Honduras, and 

 Nicaragua), wing 187.3-208.2 (197.0), tail 146.0-163.5 (153.6), cul- 

 men from base 57.4-61.1 (58.8), tarsus 43.8-46.9 (45.2) mm. 



