were observed during a survey of Trout Creek where they have been 

 observed in at least one of the past five years. 



Glacier National Park . Brood surveys were conducted along 24 km 

 of the McDonald Creek drainage on 10-11 August 1992 and along 16 

 km again on 2 September 1992 (Table 1) . A minimum of 50 

 different harlequin ducks (129; 13-14 broods of 1, 1, 2, 2, 3, 3, 

 3, 4, 4, 4, 7, and a group of 8 young with two size classes 

 present) were observed on McDonald Creek and an additional 3 (19 

 with 2 young) on Mineral Creek (Table 1, Appendix B & C) . Many 

 other surveys were conducted throughout the season by Glacier 

 National Park personnel (Ashley 1992) . These surveys found 

 considerable mixing of broods, both before and after marking on 

 10-11 August. 



Breeding Chronology and Effects on Surveying . Breeding was very 

 early this year, probably due to very low flows during spring 

 "runoff. As a result, most females apparently began egg laying 

 and incubation several weeks early; males had left by the second 

 pair survey of Marten Creek on 1 June. The last male was seen on 

 McDonald Creek on 23 June 1992 about 10 days earlier than 

 reported in 1973-75 (Kuchel 1977, Ashley 1992). All young were 

 fledged or nearly flying by 4 August on Marten Creek and 12 

 August on Trail Creek. Some females and young left Marten Creek 

 by 7 August. If other streams surveyed were more advanced 

 chronologically, birds might have already left for the coast by ■ 

 the time the streams were surveyed for broods. However, most 

 females and young were still present on 11 August at McDonald 



