Record Details
Field | Value |
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Title | Habitat use, movements, and behavior of postbreeding female canvasbacks in Manitoba |
Names |
Devries, James H.
(creator) Jarvis, Robert L. (advisor) |
Date Issued | 1993-02-11 (iso8601) |
Note | Graduation date: 1993 |
Abstract | The habitat use, movements, and behavioral energetics of unsuccessfully breeding female canvasbacks (Aythya valisineria) were examined during the preflightless period in southern Manitoba during 1989-90. Following breeding attempts, unsuccessful females generally expanded their home range on the breeding area, remained there for up to one month, preferentially used large semipermanent and permanent wetlands, and were gregarious. Nocturnal shifts in habitat use were apparent and may be an adaptation to avoid predation by mink. Unsuccessful females depart the breeding area to participate in a moult migration of up to 300 km independent of the departure of males. Wetlands approximately 40 km north of the breeding area appear to serve as staging wetlands for the moult migration. Both Swan Lake and Dauphin Lake in central Manitoba appear to be important moulting waters for unsuccessful females. Time spent on the breeding area and on staging wetlands may be required to replenish fat reserves for the moult migration, the moult itself, and upcoming fall migration. During the preflightless period, females spend approximately 40% of their diurnal energy budget feeding and their daily energy expenditure is approximately 1200-1300 kJ. The cost of the moult migration from the breeding area to Swan Lake is estimated to be between 1700 and 3100 kJ requiring between 40 and 80 g of stored body fat. This study underscores the importance of breeding, staging and moulting habitats to female canvasback populations in Manitoba. |
Genre | Thesis/Dissertation |
Topic | Canvasback -- Manitoba |
Identifier | http://hdl.handle.net/1957/36003 |