We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
The distribution, phenology, and prey of harlequin ducks, Histrionicus histrionicus, in a Cascade Mountain stream, Oregon
- Authors
Jarvis, Robert; Bruner, Harold; Dowlan, Steve; Li, Judith L.; Wright, Kristopher K.
- Abstract
We examined the phenplogy, abundance, and in-stream habitat use of Harlequin Ducks (Histrionicus histrionicus) and their primary prey, the caddisfly larvae Dicosmoecus gilviper, in a Cascade Mountain streamfrom 1994-1997. Harlequins and U. gilvipes inhabited the stream fromlate April through late July, and both frequented areas with high proportions of bedrock. When broods were present in late June and July,D. gilvipes made up over 80% of harlequin diets. Although harlequinsforaged intensively on D. gilvipes, we found no direct relationship between harlequin distribution and caddisfly abundance at nine 50 m study sites. After a severe flood in early 1996, we observed reductions in overall harlequin numbers, a seasonal delay in brood development, and a decrease in abundance of D. gilvipes.
- Subjects
OREGON; UNITED States; EGG incubation; HARLEQUIN duck; PHENOLOGY; PREDATION; RIVER ecology
- Publication
Canadian Field-Naturalist, 2000, Vol 114, Issue 2, p187
- ISSN
0008-3550
- Publication type
Article