Breeding Chronology ,,.ii..f • : ' 



Breeding was early again this year, probably due to rapid spring runoff in May. As a result, 

 many females apparently began incubation by mid-May. All young were nearly or completely 

 fledged by the end of July on the Lower Clark Fork and North Fork Flathead drainages and 6 

 August on the South Fork Flathead drainages. This may have caused us to miss some broods on 

 streams in both the lower Clark Fork drainage and Trail Creek. However, very low reproduction 

 on Logan Creek this year, and high reproduction on the South Fork Flathead drainages make 

 evaluation of this situation questionable. 



Reproduction /'' 



Harlequins were present this year on at least 1 1 streams in the study area (not including 

 Glacier National Park) and adult females or broods were seen on 8 of those streams. A minimum 

 of 35 adult females were present. Late- July to early- August brood size on all streams averaged 

 4.00 (n= 1 0). This was higher than in 1 992 (3 .27) or 1 993 (2.8 1 ). Most broods were seen in 

 Class III or fledged stages of development (Bellrose 1976:27), and we made no adjustment for 

 age of broods in our calculation of mean brood size. 



We identified 30 individual females on streams during spring and summer surveys. In 

 addition, 5 females were identified during summer surveys where no spring surveys were 

 conducted. Of 30 potential broods on streams surveyed both in spring for pairs and summer for 

 broods, a minimum of 10 broods were produced for a 33% success rate of broods per adult 

 female (Table 1). From 1989 to 1994 (Table 2), the success rate averaged 44.8% (range = 24- 

 55%; n = 230 pairs on 35 streams). In 1994, the differences in numbers of young produced 

 between the South Fork Flathead drainage (50) and other drainages (17 plus ?? in Glacier 







