Rodrigues and Rodrigues • CHARACTERISTICS OF HYACINTH VISORBEARERS 727 
FIG. 1. A = adult male. B = juvenile male. C = adult female, D = juvenile female, and E = juvenile of indeterminate 
gender of the Hyacinth Visorbearer. 
replaced by feathers with the characteristic adult 
coloration as the individual age classes. Field 
observations indicate n is possible to differentiate 
fledgling juvenile males and females. 
Little is known about the life history of this 
endemic hummingbird despite the importance of 
the reproductive period of a particular species 
being fundamental to establishment of conserva¬ 
tion and management programs. There are records 
of active nests with two eggs in January (Ruschi 
1962), females building nests in July (Grantsau 
1988), two active nests in June and July 
(Vasconcelos et al. 2001), and another nest 
discovered in July that was active in August and 
September (Costa and Rodrigues 2007). Thus, it 
remains unclear whether there is a well-defined 
reproductive period in this species. 
Our objectives were to: (1) ascertain whether or 
not there is significant size dimorphism between 
adult male and female Hvacinlh Visorbcarers, (2) 
describe the plumage patterns of juveniles, and (3) 
document the reproductive period of this species 
