our goals included identifying and describing nesting, brood 

 rearing, and migratory habitat; and to collect stream habitat 

 data. 



This report presents the findings of the 1990 field season 

 and a brief overview of the natural history and habitat 

 requirements of the harlequin duck as understood to date. 



OVERVIEW 



Description 



The harlequin duck is a small yet powerful diving duck. The 

 males are exquisitely colored with slate grays, rusts, and 

 brilliant white streaks and spots. Females are subtlety colored 

 with a slate grayish-brown body and slightly lighter breast area. 

 Both male and females have prominent white head patches. 

 Coloration of juveniles (young of the year) resembles the female. 



As the down disappears from the young and ducklings increase 

 in size, it becomes difficult to distinguish juveniles from the 

 adult female. The white head patches appear more mottled on the 

 juveniles than on the adult females. Observations of behavior 

 among the family group and reactions to disturbances can be 

 helpful to distinguish adults from young. We observed the adult 

 females to have a more alert behavior, looking around frequently, 

 while the juveniles appeared to be concerned only of their 

 immediate environment, unaware of the surroundings beyond. 

 Adults usually reacted to our presence where juveniles often 

 seemed unaware or aloof. 



